Horse Power, Track Shit, Torque, Cubic Inches, Liters, Run What Ya Brung, Auto or Cycle

I spun my LSA to 7100 with the stock heads, and those have some heavy valves. A set of stiff valvesprings and Ti retainers did their jobs - it never broke anything, just wore out valve guides kinda quickly. As you're well aware, the various forces increase with higher revs at an exponential rate, and road courses put some nasty demands on a motor. A single 20-minute session might be equal to a half-season of 1/8-mile passes, so be careful from whom you solicit advice.

It may be worthwhile to check out an aftermarket intake manifold. The factory LS2, LS3, and TrailBlazer SS intakes are outstanding for street cars which operate in the midrange, but something with shorter runners might work better in your application.
 
I spun my LSA to 7100 with the stock heads, and those have some heavy valves. A set of stiff valvesprings and Ti retainers did their jobs - it never broke anything, just wore out valve guides kinda quickly. As you're well aware, the various forces increase with higher revs at an exponential rate, and road courses put some nasty demands on a motor. A single 20-minute session might be equal to a half-season of 1/8-mile passes, so be careful from whom you solicit advice.

It may be worthwhile to check out an aftermarket intake manifold. The factory LS2, LS3, and TrailBlazer SS intakes are outstanding for street cars which operate in the midrange, but something with shorter runners might work better in your application.

Yea im aware of the LS's wearing shit at an exponential rate. I had a C6Z with the infamous valve guide wear issue. Had the heads redone, did a small BTR cam and all that shit. Everybody said change the valve springs every 20k miles LOL.

The LS's once you get a roller rocker on them are much more gentle on the valve guide and valve stem because you stop side loading them.

I'll likely run something "cheap" like a Yella Terra.

I also wont run GM lifters as they are garbage... Might run Johnsons, but really want to run a solid roller, especially if I am going to run something like a Yella Terra thats adjustable. Johnson doesnt make a solid roller for the LS. Morel does, but I dont know much about their quality. Johnson big wheel lifters are interesting as they supposedly slow the wheel speed down and give better life, but damn they are fucking pricey, then you have to get a cam cut for them.

I'm looking at shelf cams and seeing Tick has a road race cam which I have read a bit about and seems like their lobe's are pretty gentle. I like BTR stuff but their road course(if you can call it that) cam is not in production anymore. I'm partial to Cam Motion cores, but they dont have any cams for road course stuff, only drag racing, nitrous, etc...
 
Yea im aware of the LS's wearing shit at an exponential rate. I had a C6Z with the infamous valve guide wear issue. Had the heads redone, did a small BTR cam and all that shit. Everybody said change the valve springs every 20k miles LOL.

The LS's once you get a roller rocker on them are much more gentle on the valve guide and valve stem because you stop side loading them.

I'll likely run something "cheap" like a Yella Terra.

I also wont run GM lifters as they are garbage... Might run Johnsons, but really want to run a solid roller, especially if I am going to run something like a Yella Terra thats adjustable. Johnson doesnt make a solid roller for the LS. Morel does, but I dont know much about their quality. Johnson big wheel lifters are interesting as they supposedly slow the wheel speed down and give better life, but damn they are fucking pricey, then you have to get a cam cut for them.

I'm looking at shelf cams and seeing Tick has a road race cam which I have read a bit about and seems like their lobe's are pretty gentle. I like BTR stuff but their road course(if you can call it that) cam is not in production anymore. I'm partial to Cam Motion cores, but they dont have any cams for road course stuff, only drag racing, nitrous, etc...


I know you are looking for an aluminum block but I have a fresh from machine shop built 5.3 iron block with new Gen IV rods and new LS pro pistons for sale. $2400
 
I know you are looking for an aluminum block but I have a fresh from machine shop built 5.3 iron block with new Gen IV rods and new LS pro pistons for sale. $2400

to heavy for a miata unfortunately... I need the weight savings of aluminum. I have read the iron LS motors are about 100lbs heavier than the aluminum equivalent. I've read the Gen 4 motors are about 10-15 lbs heavier than the Gen 3 due to all the added strength in the block, but IMO thats good added weight. Probably lightest LS motor would be an LS6 or late LS1(after the basically became an LS6 minus the cam and some other bits).

With an aluminum motor, TKX 5spd and an aluminum Ford 8.8 IRS rear end you end up ~100lb total weight difference from the OEM setup. A miata motor is ~300lbs while an LS is ~400-415. TKX 5spd weighs 100lbs, Miata 6spd weighs ~90lbs. Rear Miata diff is ~61lbs. Aluminum ford 8.8 is ~67lbs... You drop like 10lbs off the front using the V8Roadsters front subframe... So you can realistically stay within 100-120lbs of the factory setup. My LS setup shouldnt weigh quite 415 as I wont have power steering pump, AC, etc... which is usually figured into those hanging weights....

Appreciate the offer though.
 
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That was honestly my original intent with this car was a K24A2...

But I've read of FAR to many that blow up when using them on the track exclusively... I know personally 3 guys that blew up K24 motors in their miata's on track. I think on street they are a fantastic swap, but for a dedicated track car, no thanks.

They have the same "basic" issue that the Mazda BP engines have as far as longevity goes... you have to beat the dog brains out of them and spin them to the moon to be in the power band. With an LS you simply dont have to do this so longevity goes way way way up. Put a trans thats 600hp capable behind a 300hp engine and a rear end that handles 800hp Mustang Cobra launches and you have a pretty bullet proof platform. You can lope around the track in an LS miata as they have more torque just off idle than a BP or K series has at peak.
 
The K24Z3 is naturally aspirated and only gets to 200ish-whp, when you turn't up with turbo stuff goes kaboom on circuit (ask me how I know).

Grassroots Motorsports put a GM LFX 3.6L V6 into their Miata, that seems like a pretty good compromise - cheaper and less weight than a LS while still 300bhp+
 
The K24Z3 is naturally aspirated and only gets to 200ish-whp, when you turn't up with turbo stuff goes kaboom on circuit (ask me how I know).

Grassroots Motorsports put a GM LFX 3.6L V6 into their Miata, that seems like a pretty good compromise - cheaper and less weight than a LS while still 300bhp+

I know what the K24Z3 is...doesnt change the fact that there are lots of blown up K series motors in dedicated track cars... to many for me to want to gamble on it at the costs involved of 12-15k to do everything correctly... If you dont blow the motor up, the power is on the edge of what the Miata 6 spd can reliably hold... so then you blow transmissions up... Its just something I dont want to play with..ragged edge shit and on the verge of blowing up shit. If you do the swap thinking "ill keep the Miata 6 spd" you then have a 2k dollar adapter plate and clutch for that transmission... if you decide after you blow up a trans or two that you want to swap to the BMW ZF trans you gotta sink another 2k bucks into a different adapter plate and clutch for the BMW trans...

And the LFX has its own issues of blowing up due to oil starvation. My buddy almost bought an LFX powered Miata that came with 2 spare motors...because they constantly blew up according to the seller LOL. They "thought" they had the issue sorted with the motor in the car and I think modified oiling system, might have done a custom dry sump. Then you have the not great trans they are paired with.. Again, for the cost and possible headache, the LS swap makes more sense. Its only about 30-40lbs heavier than the LFX swap and you get to use a trans thats beefcake.

There is a reason a ton of people swap LS motors into these cars... You arent driving them on the ragged edge. Everything for LS is designed for cars that are 3500+ lbs and trucks that are 5k+ lbs... and you put that stuff in a car that weighs 2300lbs that you cant put enough tire on to cause issues.
 
Anybody have a decent source for LS2 or other aluminum 6.0 blocks or short blocks that arent raped by BFC priced?

Starting to look for parts to LS swap the Miata and everything local to me is stupid fucking money for a junkyard pull... Sorry not paying 3k bucks for a 195k mile junkyard pull longblock...

Looking at doing a de-stroked LS2 with a 4.8 crank to slow piston speed down when spinning to 7500-8k RPM. Probably throw some 821 LS3 heads on it so it can breath. Some kind of solid roller lifters and roller rockers.
IIRC there's a few kits for putting a 5.0 Ford in the Miata. The one I saw you could run the stock hood up to 500 hp.
 
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Well, the whole exponential-wear thing ain't just a LS phenomenon - physics is a bitch. It's just more of a bitch when revving to the moon with a heavy and flexible set of Tinker Toys in the valvetrain. If you're a recovering LS7 owner, then I'm not telling you anything new.

Much of my response in this dialogue is being swayed by my current projects which are generally not high-revving affairs. If you wanna zig this thing to the far reaches of the tach, I'm excited to see the results. Should be a hell of a build (y)

Sucks to hear that the LFX isn't a workable option - seems like a good match to a vehicle that's 1500 lbs lighter than a Camaro.
 
Well, the whole exponential-wear thing ain't just a LS phenomenon - physics is a bitch. It's just more of a bitch when revving to the moon with a heavy and flexible set of Tinker Toys in the valvetrain. If you're a recovering LS7 owner, then I'm not telling you anything new.

Much of my response in this dialogue is being swayed by my current projects which are generally not high-revving affairs. If you wanna zig this thing to the far reaches of the tach, I'm excited to see the results. Should be a hell of a build (y)

Sucks to hear that the LFX isn't a workable option - seems like a good match to a vehicle that's 1500 lbs lighter than a Camaro.

I mean all the motor swaps are within a little bit of money of each other. The LS swap is definitely on the higher end simply due to engine and trans cost. It used to not be a problem to get an LS/T56/6060 pull from a Camaro for dirt cheap, like 3k all in. But not anymore...

I just see me getting a 5.3 pull out for 2000 or whatever and then cracking it open to put bearings, rings, head gaskets, cam, lifters, roller rockers, etc... into it and im thinking I might be better off $$$$ just building something and knowing what I have... problem is staying under control. But I have no need for any crazy forged pistons or rods or anything at the power levels I am talking about running so I can find take off parts from guys who HAVE done those swaps for cheap. Im finding used GM rods and pistons for like 100 bucks for a set.
 
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Probably just noise from the direct injection. I've heard those injectors can be loud.
I appreciate your optimism...but in this case, its definitely mechanical and most likely a bearing departed the chat. In person it sounds like a 12v Cummins or if I'm being generous, a shitbox diesel Jetta.

I'm just glad the damn thing started so I could get it off the trailer for its heart transplant.
 
I appreciate your optimism...but in this case, its definitely mechanical and most likely a bearing departed the chat. In person it sounds like a 12v Cummins or if I'm being generous, a shitbox diesel Jetta.

I'm just glad the damn thing started so I could get it off the trailer for its heart transplant.

Yeah, my comments were in jest, and my condolences for your loss. What's going in next?
 
Yall seen anybody throw a couple snails or a blower on the LT6 and see what that bitch will do? Looks pretty legit. Sounds like they liked what they saw in Ford's 5.2 GT350 motor...


Unless its got the same ECU as the Stingray, there will be no way to tune it(currently)... HP Tuners has cracked the Stingray ECU.

And it being a fairly high strung engine anyway, I dont think I would trust a piggyback running an extra set of injectors.
 
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376172017_9928817300525008_7366947006625992306_n.jpeg
 
Saw this outside my local(ish) hardware store today…I thought it was actually pretty cool.

View attachment 8234225

Not every day you see a beat to hell and bubbafied, lifted AWD turbodiesel Merc!
Not everybody can afford a level 7 armored G-wagon or Unimog... some have to make do with "tactical" lever guns instead.
 
OK I know there are quite a few guys in here that REALLY know LS's... far better than I...

So looking for some opinions and advice on what I am thinking for my track Miata... I'm not after an HP monster as its not needed... and having lower torque is actually an advantage to not spinning the car at every fucking corner.

De-stroked 6.0 back to a.......5.3 LOL... basically to slow piston speed down when trying to rev it to 7500ish...

To rev to 8k+ seems to require a dry sump and a really really stout top end...7500 is a different ball game and much easier to attain... 7k is childs play. Not trying to kill myself financially with this build, but im not seeing any pull outs that are "cheap"... an aluminum 5.3 pull out is like 2500-3k with 150-200k miles on it... and I would still probably want to do bearings and rings and any truck pull needs a car intake manifold for my swap...plus an oil pan... so I have been contemplating building something "low dollar" from a bare block.

6.0 LS block, probably an L76 block as thats what's available without spending way to much on a fucking bare block. Can get one for like 600 bucks. Obviously needs a DOD delete valley plate, but every block I look at doesnt have any valley plate so 70 bucks solves that.

4.8, 58x crank. Will get some cheap OE crank from a dismantler and have the machine shop polish everything and balance it.

4.8 GM rods... they will definitely withstand the HP levels I am after.

6.0 pistons... cheap is used GM, probably ok for me with new rings. Summit has some decently priced forged pistons, but I dont know that they are needed at the power level I am looking at, BUT the resistance to detonation damage is enticing... I only want to run 93 as its easy to get, but E85 is in the cards, just not readily available at every track I go to so...

821 LS3 heads... some kind of dual springs, depends on the cam obviously... titanium valves... was thinking Titanium intake and GM LY6 Inconel exhaust, but I dont think the Inconel is needed for an N/A motor and the lighter titanium is probably where I want to be for valve train stability at high RPM anyway... Mast makes both titanium intake and exhaust for a decent price... Titanium retainers...

Morel solid roller lifters. Would love Johnsons, but they are real proud of their shit...2x + as expensive as morel's.

Yella Terra roller rocker arms... these are "cheap" and are bolt on... I dont really want to get into much machining of the head or anything like that for shaft mount rocker system or anything crazy... These arent the lightest solution, but its bolt on... ~600 bucks... I mean shit a CHE trunion bushing kit for factory rockers is north of $200...and you are still dealing with GM rockers side loading the valves...

Cam... I have a few contacts on getting me a cam setup. I prefer cam-motion cores so... Looking at BTR or Tick or have a local place(Horse Power Research) that does good shit and I know what of the guys there.


There's obviously a bunch of ancillary shit that goes on a motor, but that stuff is less about options and more about "this is the only thing that fits"... Mast oil pan, LS3 intake manifold, GTO exhaust manifolds(or high dollar V8R headers), etc...

Planning to run it all on a Terminator of some sort.
 
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OK I know there are quite a few guys in here that REALLY know LS's... far better than I...

So looking for some opinions and advice on what I am thinking for my track Miata... I'm not after an HP monster as its not needed... and having lower torque is actually an advantage to not spinning the car at every fucking corner.

De-stroked 6.0 back to a.......5.3 LOL... basically to slow piston speed down when trying to rev it to 7500ish...

To rev to 8k+ seems to require a dry sump and a really really stout top end...7500 is a different ball game and much easier to attain... 7k is childs play. Not trying to kill myself financially with this build, but im not seeing any pull outs that are "cheap"... an aluminum 5.3 pull out is like 2500-3k with 150-200k miles on it... and I would still probably want to do bearings and rings and any truck pull needs a car intake manifold for my swap...plus an oil pan... so I have been contemplating building something "low dollar" from a bare block.

6.0 LS block, probably an L76 block as thats what's available without spending way to much on a fucking bare block. Can get one for like 600 bucks. Obviously needs a DOD delete valley plate, but every block I look at doesnt have any valley plate so 70 bucks solves that.

4.8, 58x crank. Will get some cheap OE crank from a dismantler and have the machine shop polish everything and balance it.

4.8 GM rods... they will definitely withstand the HP levels I am after.

6.0 pistons... cheap is used GM, probably ok for me with new rings. Summit has some decently priced forged pistons, but I dont know that they are needed at the power level I am looking at, BUT the resistance to detonation damage is enticing... I only want to run 93 as its easy to get, but E85 is in the cards, just not readily available at every track I go to so...

821 LS3 heads... some kind of dual springs, depends on the cam obviously... titanium valves... was thinking Titanium intake and GM LY6 Inconel exhaust, but I dont think the Inconel is needed for an N/A motor and the lighter titanium is probably where I want to be for valve train stability at high RPM anyway... Mast makes both titanium intake and exhaust for a decent price... Titanium retainers...

Morel solid roller lifters. Would love Johnsons, but they are real proud of their shit...2x + as expensive as morel's.

Yella Terra roller rocker arms... these are "cheap" and are bolt on... I dont really want to get into much machining of the head or anything like that for shaft mount rocker system or anything crazy... These arent the lightest solution, but its bolt on... ~600 bucks... I mean shit a CHE trunion bushing kit for factory rockers is north of $200...and you are still dealing with GM rockers side loading the valves...

Cam... I have a few contacts on getting me a cam setup. I prefer cam-motion cores so... Looking at BTR or Tick or have a local place(Horse Power Research) that does good shit and I know what of the guys there.


There's obviously a bunch of ancillary shit that goes on a motor, but that stuff is less about options and more about "this is the only thing that fits"... Mast oil pan, LS3 intake manifold, GTO exhaust manifolds(or high dollar V8R headers), etc...

Planning to run it all on a Terminator of some sort.
@E. Bryant
 
OK I know there are quite a few guys in here that REALLY know LS's... far better than I...

So looking for some opinions and advice on what I am thinking for my track Miata... I'm not after an HP monster as its not needed... and having lower torque is actually an advantage to not spinning the car at every fucking corner.

De-stroked 6.0 back to a.......5.3 LOL... basically to slow piston speed down when trying to rev it to 7500ish...

To rev to 8k+ seems to require a dry sump and a really really stout top end...7500 is a different ball game and much easier to attain... 7k is childs play. Not trying to kill myself financially with this build, but im not seeing any pull outs that are "cheap"... an aluminum 5.3 pull out is like 2500-3k with 150-200k miles on it... and I would still probably want to do bearings and rings and any truck pull needs a car intake manifold for my swap...plus an oil pan... so I have been contemplating building something "low dollar" from a bare block.

6.0 LS block, probably an L76 block as thats what's available without spending way to much on a fucking bare block. Can get one for like 600 bucks. Obviously needs a DOD delete valley plate, but every block I look at doesnt have any valley plate so 70 bucks solves that.

4.8, 58x crank. Will get some cheap OE crank from a dismantler and have the machine shop polish everything and balance it.

4.8 GM rods... they will definitely withstand the HP levels I am after.

6.0 pistons... cheap is used GM, probably ok for me with new rings. Summit has some decently priced forged pistons, but I dont know that they are needed at the power level I am looking at, BUT the resistance to detonation damage is enticing... I only want to run 93 as its easy to get, but E85 is in the cards, just not readily available at every track I go to so...

821 LS3 heads... some kind of dual springs, depends on the cam obviously... titanium valves... was thinking Titanium intake and GM LY6 Inconel exhaust, but I dont think the Inconel is needed for an N/A motor and the lighter titanium is probably where I want to be for valve train stability at high RPM anyway... Mast makes both titanium intake and exhaust for a decent price... Titanium retainers...

Morel solid roller lifters. Would love Johnsons, but they are real proud of their shit...2x + as expensive as morel's.

Yella Terra roller rocker arms... these are "cheap" and are bolt on... I dont really want to get into much machining of the head or anything like that for shaft mount rocker system or anything crazy... These arent the lightest solution, but its bolt on... ~600 bucks... I mean shit a CHE trunion bushing kit for factory rockers is north of $200...and you are still dealing with GM rockers side loading the valves...

Cam... I have a few contacts on getting me a cam setup. I prefer cam-motion cores so... Looking at BTR or Tick or have a local place(Horse Power Research) that does good shit and I know what of the guys there.


There's obviously a bunch of ancillary shit that goes on a motor, but that stuff is less about options and more about "this is the only thing that fits"... Mast oil pan, LS3 intake manifold, GTO exhaust manifolds(or high dollar V8R headers), etc...

Planning to run it all on a Terminator of some sort.

I'm telling you, lol, ive got the shortblock that you need other than it being a 5.3 iron block.

As far as lifters go, I know u don't want to pay Johnson lifter money but the Johnson short travels are going to be the ones to allow revs to 8k plus without the solid lifter drama. It's actually a great place to spend the money.
 
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I'm telling you, lol, ive got the shortblock that you need other than it being a 5.3 iron block.

As far as lifters go, I know u don't want to pay Johnson lifter money but the Johnson short travels are going to be the ones to allow revs to 8k plus without the solid lifter drama. It's actually a great place to spend the money.

yea im not sold on going one way or the other...

The yella terra non-adjustables for a hydraulic roller are ~100 cheaper...(450 vs. 650).

The lightweight Morel solid rollers are ~500... For what I am doing the lightweight ones "should" be more than enough strength. Johnson short travel's are 875... So a $375 swing, but a $100 savings to be able to run non-adjustable roller rockers so $275...which in the grand scheme isnt a huge amount.

I dont think I am going to, at least initially, spin the motor to 8k since that really requires a dry sump setup and the Avaid stuff is ~3k...and packaging all of that plus a 2-3 gallon reservoir in a miata engine bay is, lets just say, difficult.

Im planning to run a Holly 302-3 pan that ill snag from Improved Racing with their pan baffle, 3/4 windage tray, etc... that setup should be pretty good and be 1/3 the price of a dry sump. Probably run a regular Katech pump.

I probably will run an accusump though.
 
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OK I know there are quite a few guys in here that REALLY know LS's... far better than I...

So looking for some opinions and advice on what I am thinking for my track Miata... I'm not after an HP monster as its not needed... and having lower torque is actually an advantage to not spinning the car at every fucking corner.

De-stroked 6.0 back to a.......5.3 LOL... basically to slow piston speed down when trying to rev it to 7500ish...

To rev to 8k+ seems to require a dry sump and a really really stout top end...7500 is a different ball game and much easier to attain... 7k is childs play. Not trying to kill myself financially with this build, but im not seeing any pull outs that are "cheap"... an aluminum 5.3 pull out is like 2500-3k with 150-200k miles on it... and I would still probably want to do bearings and rings and any truck pull needs a car intake manifold for my swap...plus an oil pan... so I have been contemplating building something "low dollar" from a bare block.

6.0 LS block, probably an L76 block as thats what's available without spending way to much on a fucking bare block. Can get one for like 600 bucks. Obviously needs a DOD delete valley plate, but every block I look at doesnt have any valley plate so 70 bucks solves that.

4.8, 58x crank. Will get some cheap OE crank from a dismantler and have the machine shop polish everything and balance it.

4.8 GM rods... they will definitely withstand the HP levels I am after.

6.0 pistons... cheap is used GM, probably ok for me with new rings. Summit has some decently priced forged pistons, but I dont know that they are needed at the power level I am looking at, BUT the resistance to detonation damage is enticing... I only want to run 93 as its easy to get, but E85 is in the cards, just not readily available at every track I go to so...

821 LS3 heads... some kind of dual springs, depends on the cam obviously... titanium valves... was thinking Titanium intake and GM LY6 Inconel exhaust, but I dont think the Inconel is needed for an N/A motor and the lighter titanium is probably where I want to be for valve train stability at high RPM anyway... Mast makes both titanium intake and exhaust for a decent price... Titanium retainers...

Morel solid roller lifters. Would love Johnsons, but they are real proud of their shit...2x + as expensive as morel's.

Yella Terra roller rocker arms... these are "cheap" and are bolt on... I dont really want to get into much machining of the head or anything like that for shaft mount rocker system or anything crazy... These arent the lightest solution, but its bolt on... ~600 bucks... I mean shit a CHE trunion bushing kit for factory rockers is north of $200...and you are still dealing with GM rockers side loading the valves...

Cam... I have a few contacts on getting me a cam setup. I prefer cam-motion cores so... Looking at BTR or Tick or have a local place(Horse Power Research) that does good shit and I know what of the guys there.


There's obviously a bunch of ancillary shit that goes on a motor, but that stuff is less about options and more about "this is the only thing that fits"... Mast oil pan, LS3 intake manifold, GTO exhaust manifolds(or high dollar V8R headers), etc...

Planning to run it all on a Terminator of some sort.

So to be up front, none of this is a bad plan, even if it tends to go in the opposite direction that my recent thinking (which is building a 6.0L torquer for a 4250 lb sedan).

Factory cranks are great. Have your machine shop give it a once-over and that's the last time you'll think about it, or at least until the bearings go because of oil starvation due to sustained 2g+ cornering.

My biggest concern with using factory pistons would be: 1) the resulting compression ratio is likely not high enough for my liking when combined with the huge can required to spin to 8k; and 2) you can't do a simple 0.005" clean-up pass on the block. Are those good enough reasons to drop another $1500-2000 on some fancy forged parts? Not my checkbook, not my call. I'd love to be a snob here, but too many people have beaten the piss out of junkyard motors for the past two decades for me to act like the factory parts are inadequately strong.

Rec-port heads are a great choice on a budget. If you're doing new intake valves then you can indeed buy the cheaper LY6/L96 truck heads and get the Inconel exhaust valves. I'd be fine with running factory LS3 valves on both sides; as you point out, Inconel on the exhaust is overkill for N/A and I don't get warm fuzzies from the LS9 Ti valves (especially at $125/each). I don't think you need to get too fancy with porting on an engine of this displacement, but Katech has some decent prices if you decide to go that route. I would try to leave the combustion chamber untouched to retain as much comp ratio as possible.

The intake manifold will be just as critical as the cam selection in making power up top. Fortunately, almost all of the aftermarket intakes that fit under a car hood have shorter runners than the LS3 manifold, and that's the direction you need to go. Something like the BTR Trinity will trade power below ~6k for much more up top compared to the long-runner LS3. I don't know exactly what fits under your hood, but I think you'll find plenty of good choices.

Can you fit the 2014-'15 Z28 headers? If not, then I might look at the various shorty/mid-length tubular header options for 4th-gen F-bodies or older GM swaps, since at least one of them is likely to get you an exhaust outlet in roughly the correct spot relative to cast manifolds. I haven't personally run factory cast manifolds at anything close to these revs, but I can't imagine that they are optimal.

Good luck - this will be a wickedly fun car.
 
So to be up front, none of this is a bad plan, even if it tends to go in the opposite direction that my recent thinking (which is building a 6.0L torquer for a 4250 lb sedan).

Factory cranks are great. Have your machine shop give it a once-over and that's the last time you'll think about it, or at least until the bearings go because of oil starvation due to sustained 2g+ cornering.

My biggest concern with using factory pistons would be: 1) the resulting compression ratio is likely not high enough for my liking when combined with the huge can required to spin to 8k; and 2) you can't do a simple 0.005" clean-up pass on the block. Are those good enough reasons to drop another $1500-2000 on some fancy forged parts? Not my checkbook, not my call. I'd love to be a snob here, but too many people have beaten the piss out of junkyard motors for the past two decades for me to act like the factory parts are inadequately strong.

Rec-port heads are a great choice on a budget. If you're doing new intake valves then you can indeed buy the cheaper LY6/L96 truck heads and get the Inconel exhaust valves. I'd be fine with running factory LS3 valves on both sides; as you point out, Inconel on the exhaust is overkill for N/A and I don't get warm fuzzies from the LS9 Ti valves (especially at $125/each). I don't think you need to get too fancy with porting on an engine of this displacement, but Katech has some decent prices if you decide to go that route. I would try to leave the combustion chamber untouched to retain as much comp ratio as possible.

The intake manifold will be just as critical as the cam selection in making power up top. Fortunately, almost all of the aftermarket intakes that fit under a car hood have shorter runners than the LS3 manifold, and that's the direction you need to go. Something like the BTR Trinity will trade power below ~6k for much more up top compared to the long-runner LS3. I don't know exactly what fits under your hood, but I think you'll find plenty of good choices.

Can you fit the 2014-'15 Z28 headers? If not, then I might look at the various shorty/mid-length tubular header options for 4th-gen F-bodies or older GM swaps, since at least one of them is likely to get you an exhaust outlet in roughly the correct spot relative to cast manifolds. I haven't personally run factory cast manifolds at anything close to these revs, but I can't imagine that they are optimal.

Good luck - this will be a wickedly fun car.

Yea the factory cranks at the power level I will be at ~300-350 are plenty capable. The bearing starving issue is why I will likely run an accusump as well as the baffle from Improved Racing. I will also likely drill the lifter buckets to let oil drain to the pan faster.

If I get a block thats clean, I will likely either dingle-ball hone it at the house or pay to get it power honed...or maybe not if the cross hatching still looks good...but at a minimum ill likely dingle ball hone it. The forged pistons from Summit are only like 600 bucks so they are relatively cheap. And again, the cast factory pistons are likely completely up to the task of my power goals... only thought on forged is for a bit more robust piston in case of detonation. Ill likely run a bit wider ring gap on whatever I run. Getting a block setup for forged pistons with a small cut and hone is likely at least 1k bucks in machine work... I would "like " to avoid that kind of expense... at that point getting a "cheap" used block goes out the window reman blocks from GM can be had for ~1500...and I dont have to waste time at the machine shop...

I have found a few decently price used sets of 821 heads... they should have hollow stem intakes at least. Titanium valves are probably well outside of my budget and purpose really. Not planning on doing anything to the heads but a light refresh with seals, MAYBE an 020 deck, and check the guides. Then throw new springs, titanium retainers and the yella terra roller rockers on them.

I'm likely just going to with LS3 intake manifold for now as they are cheap. LS6/LS2 manifolds are expensive, like 1000 bucks expensive, where as LS3 manifolds are like 200 bucks... One guy I know is running ITB's and they sound fucking glorious...


As far as headers/manifolds, there are only a very few that will fit at all. GTO manifolds fit and are cheap. Can likely send them for some porting and coating. V8R makes headers but they are $1200... and again, at the power level I am going to be at, cast manifolds are fine. I think there are maybe 2 or 3 other options, but not much out there that fit.
 
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Tell me you're a pilot without telling me you're a pilot...lol

Its all in the planning stages now. I tend to plan big projects out to the n-th degree months in advance.

I'm not making any big financial moves right now until we get a contract which I am expecting a 30-34% pay raise. Im also about to go to captain upgrade in the next 6 months unless age 67 passes so that is another ~40% pay raise(we make 60% of an equivalent year captain on the pay scale). Then once I upgrade I will stop contributing to the 401k because the companies direct contribution plus profit sharing will fill the bucket completely... So those few things combined will basically double my salary, hopefully in the next 6 months. I also have a retro check I will have to figure out how to spend...

This project I would like to get knocked out in the off season between 2024 and 2025, so I need to start gathering parts as I find deals. There is, what looks like, a pretty clean 6.0 aluminum block in Houston for 750 bucks... im going down to Houston friday to see some family so I "may" snag it as the price is pretty good for what it looks like.
 
I appreciate your optimism...but in this case, its definitely mechanical and most likely a bearing departed the chat. In person it sounds like a 12v Cummins or if I'm being generous, a shitbox diesel Jetta.

I'm just glad the damn thing started so I could get it off the trailer for its heart transplant.
Sounds more like piston slap or convertor/flywheel bolts (cracked flywheel/flexplate ?).
Usually a rod knock doesn't sound like that at idle but only when you *lightly* rev it just a tad.

Should be an easy check if you know how to be creative.

[edit]
Almost forgot.
I have seen balancers make that exact kinda noise too....that's a very easy check.
 
Sounds more like piston slap or convertor/flywheel bolts (cracked flywheel/flexplate ?).
Usually a rod knock doesn't sound like that at idle but only when you *lightly* rev it just a tad.

Should be an easy check if you know how to be creative.

[edit]
Almost forgot.
I have seen balancers make that exact kinda noise too....that's a very easy check.
its a LOT louder when you give it even a smidge of gas....low oil pressure and a farkton of knock recorded on VCM Scanner.
 
its a LOT louder when you give it even a smidge of gas....low oil pressure and a farkton of knock recorded on VCM Scanner.

but did you develop any new holes in the block?

If no, its not really blown up...yet...

Keep sending and get back to us.


Guy at a track day last year had a "new" Supra out there... He got towed off the track at some point. His car was still sitting at the end of the day and him and his buddy were looking at it so I wandered over. I asked what had happened and he said "the insides are on the outside now"... I asked if it was stock and he said "no has a tune" and I asked "who tuned it" "i did"... hmmmm... no warranty for you... He also had no trailer so...


I cant find the video of my friend blowing the motor up in his Miata... he pulled off track immediately after it let go because he was 100% sure the insides were now outside LOL... he was right...
 
I knew that Richard Holdener must have done a video on a destroked LS and here it is:



The whole video is worth a watch as the combo worked really well, but there are some particularly salient thoughts starting around the 5:30 mark.
 
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I knew that Richard Holdener must have done a video on a destroked LS and here it is:



The whole video is worth a watch as the combo worked really well, but there are some particularly salient thoughts starting around the 5:30 mark.

I think I watched that before, but im going to watch it again.

I've reached out to BTR to see if they have any shelf cams they would recommend with that combo or if thats getting into custom grind area. Ill likely reach out to Tick also.
 
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Can you fit the 2014-'15 Z28 headers? If not, then I might look at the various shorty/mid-length tubular header options for 4th-gen F-bodies or older GM swaps, since at least one of them is likely to get you an exhaust outlet in roughly the correct spot relative to cast manifolds. I haven't personally run factory cast manifolds at anything close to these revs, but I can't imagine that they are optimal.

Looks like the LS3 Camaro manifolds work and they can be bought cheap... They dont look "terrible" honestly.
 

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If those work, will the LS7 Camaro headers also fit?

View attachment 8236662

I dont think so... at least I havent found any reference.

Looks like people either use Camaro LS3, V8R headers or Sanderson supposedly makes a set of block huggers that fit.

Honestly the Camaro LS3 will flow plenty for the power I am trying to make. If this car has 300whp it will be a fucking rocket ship... Shouldnt be hard to make 400+ at the crank so like 340-350 at the wheels... Probably doing either a 3.31 or 3.55 rear...
 
I am deeply skeptical of that thing's ability to rev to 4000 RPM or make 177 HP.
Vintage aluminum Mickey Thompson valve covers are good for a guaranteed 20 additional horsepower.
Surprisingly after 20 years of sitting in a barn it fired right up.
The thing about old Dodge pick-ups here in Oregon is that most of them went to work in the logging industry then got all used up and thrown away.
This particular unit is a one owner and as far as I can tell doesn't have but one single door ding in it.
Nor does it look like it's hauled anything in its bed.
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I got the most useless reply from BTR possible...

"you will need a custom cam for what you are doing"...

No suggestion, no questions on the overall setup, etc.... just a completely lazy response...

Pretty sure I know who I wont be buying a cam from.
 
I got the most useless reply from BTR possible...

"you will need a custom cam for what you are doing"...

No suggestion, no questions on the overall setup, etc.... just a completely lazy response...

Pretty sure I know who I wont be buying a cam from.

Talk to Aaron Shoal from SDPC. He just spec'd out my cam for this new build. Great people to deal with and Aaron's personal race car is a bad mother fucker.
 
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