5.3L LS.. 491 hp and 445 tq... woot!

[Steve1968LS2]

Since I have the dyno sheets I thought I would post..

We took off the car headers and put on a set of sand rail headers.. went to 499 hp and 455 tq.. lol.. but we can't count that one.

Here's the best with the car headers.
https://static1.pt-content.com/images/pt/2009/06/rtneys-1.jpg

https://static1.pt-content.com/images/pt/2009/06/2573x1c-1.jpg

Here's what was in the engine:

5.3 block aluminum (doesn't really matter if it's iron)
4.8 flat top pistons
5.3 rods - ARP rod bolts
5.3 crank
LS2 timing chain on 5.3 sprockets
LS2 intake/injectors/fuel rail (modified by Turn Key)
90mm Turn Key throttle body
220/224 112 LSA Trick Flow cam (.575 lift)
Trick Flow 205 CNC ported heads (assembled)
Harland Sharp pedestal mount 1.7 rockers
Trick Flow 7.500 chromemoly pushrods

Correction factor was 1.046

91 octane pump gas on a Superflow 901 engine dyno. We estimate compression at around 11.5:1

Would have pulled farther but was running out of voltage at the the upper RPM (dropping to 10.8 volts).. we need a new dyno battery.

Pretty darn happy, especially with the torque curve.

https://static1.pt-content.com/images/pt/2009/05/96answ-1.jpg

[skeeters65]

WOW great numbers...

I love the Valve covers!!!

[UNmolestedTA]

:hail: 5.3!

[ajjones44]

Damn good numbers for a 5.3!

[nightrunner]

nice numbers!

was the intake manifold modified by turn key or just the fuel rails? could probably get better numbers with a different intake manifold.

[Taylor1969]

Is there a budget buildup like this that would make close to the same power?

What would you get out of stock heads with a minor workover? I have been strongly considering a 5.3, but putting on a $2000+ set of heads kills the wallet.

[Steve1968LS2]

Is there a budget buildup like this that would make close to the same power?

What would you get out of stock heads with a minor workover? I have been strongly considering a 5.3, but putting on a $2000+ set of heads kills the wallet.

Yea, why not?

They are just 205 heads.. if you worked over a set of GM heads I imagine the power would only be down a bit. Just like the rockers.. put on the cheaper stock rockers and maybe loose 10 hp..

The biggest key to the power here was the use of 4.8 pistons which raised the compression and that's a cheap trick.

[Steve1968LS2]

nice numbers!

was the intake manifold modified by turn key or just the fuel rails? could probably get better numbers with a different intake manifold.

Stock LS2 intake.. although the IAT was mounted it it by Turn Key.

[6'9"Witha69]

Sweet. That's good power for 326 cid. And that tq curve is pretty nice as well.

[Jagarang]

Sexy!

[1badchevelle]

sure is purdy!!!

[NOPANTS-68]

simply bitchin.

Think of the costs of a Gen 1 it takes to rival that. Pretty amazing.

[SoCal Cruzer]

That's Wicked sick!!!! It would be interesting to see the power numbers below 3000 rpm to see how it would be on the street. Either way WOW!

[67CamNKC]

Very Nice......

Any plans on where you're mounting the coils and what bracket are you using?

[Steve1968LS2]

That's Wicked sick!!!! It would be interesting to see the power numbers below 3000 rpm to see how it would be on the street. Either way WOW!

We couldn't get the dyno to pull down that low.. Will try on the chassis dyno.

[Steve1968LS2]

Very Nice......

Any plans on where you're mounting the coils and what bracket are you using?

JCG Restorations made me a set of super bad ass coil relocation brackets (they in Oxnard, ask for Cris).

They will be mount below the firewall where it slopes back to the floor (sort of above the headers).

I just need to extend a few wires.

[4086D9]

Great numbers!

[formula]

JCG Restorations made me a set of super bad ass coil relocation brackets (they in Oxnard, ask for Cris).

They will be mount below the firewall where it slopes back to the floor (sort of above the headers).

I just need to extend a few wires.

Gotta see these--are they planning to sell them/you think they'd fab up another set/got any pics of the brackets/will you give them to me if I offer to fix your clock? I've been hemming and hawing over the different kits--wish the ATS kit was still available.

[BossaNova]

Beautiful engine!

[Samckitt]

That is awesome from a 326. I am about to the conclusion that I need to look for an LSx motor. Surely here in truck country I can find oodles of the 5.3s or 6.0L engines. Hmmm, then I will have to get a differrent tranny too. :-(

So the only difference in the 4.8 & 5.3 pistons is it raises compression?

Other than the heads it sounds like a pretty low budget build.

[Mr.VENGEANCE]

niiiiiceee!!!

[6'9"Witha69]

So the only difference in the 4.8 & 5.3 pistons is it raises compression?
Yes. 4.8 Pistons are flat top. 5.3 are dished. They are the same bore. easy and cheap swap.

[67CamNKC]

Same weight or is a rebalance needed?

[Steve1968LS2]

Same weight or is a rebalance needed?

We rebalanced.. I would doubt they would weigh the same (flat top vs. dish)

[Damn True]

any photos of those coil mount thingys?

[Samckitt]

If someone was to build this engine, about what would it cost?

[Samckitt]

What is the differrence in a 5.3L engine from a FWD car compared to the truck one?

[jaybee]

Sure, if you tried hard enough you could get that hp out of a 327. It sure wouldn't have that torque curve, though. A person could have a lot of fun with that under the hood.

[Samckitt]

Sure, if you tried hard enough you could get that hp out of a 327. It sure wouldn't have that torque curve, though. A person could have a lot of fun with that under the hood.

OK I am confused. What do you mean the 327 wouldnt have that torque curve? According to Steve1968ls2 these numbers are coming from a 5.3L/327.

[CarlC]

A Gen1/traditional 327.

[Samckitt]

Ah.

[lt1chevelle]

so by taking the flat tops out of the 4.8 and putting them into the 5.3 you up the compression because they 5.3 are dished?

[6'9"Witha69]

Si senor.

[camaro2nv]

any photos of those coil mount thingys?
Nice numbers!
I would like a pic also.
Are they like these?
http://www.automotivedesigneng.com/products/coil_pack.html

[jilge71]

besides used what other options on pistons are out there?

[Steve1968LS2]

Nice numbers!
I would like a pic also.
Are they like these?
http://www.automotivedesigneng.com/products/coil_pack.html

Working on it.. I forgot them at the shop. They were made by Cris over at JCG restorations in Oxnard.

[alowerlevel]

besides used what other options on pistons are out there?



They may not all make ones for 5.3's but they all have them for other LS' - Diamond, Mahle, Wiseco, JE, Probe, CP, SRP

[Steve1968LS2]

besides used what other options on pistons are out there?

Turn key does sell the pistons new and I don't think they are very spendy.

Other than that.. used. You could do the same deal with fancy aftermarket pistons but that would defeat the point.

[Steve1968LS2]

so by taking the flat tops out of the 4.8 and putting them into the 5.3 you up the compression because they 5.3 are dished?

Yup..

[1badchevelle]

Steve will the lq9 flat pistons work as well? is the reason the 4.8 were listed is for budget build?

[Steve1968LS2]

Steve will the lq9 flat pistons work as well? is the reason the 4.8 were listed is for budget build?

I'm not sure.. what bore size are they for? We used the 4.8 since they are the same bore size as the 5.3L .. that means no machine work is needed.

[Jimmy Sean]

any photos of those coil mount thingys?


Steve would these be them?

found here http://www.lateral-g.net/forums/showthread.php4?t=22536&page=3


https://static1.pt-content.com/images/noimg.gif
https://static1.pt-content.com/images/noimg.gif

[Mark Antrim]

This makes me want to junk the gen 1 and build one of these engines. I did price the pistons at work for the 4.8 stock pistons and they are a little pricey. It would be different, but dont tell the wife.

[93Polo]

Steve will the lq9 flat pistons work as well? is the reason the 4.8 were listed is for budget build?

They will not as the lq9 is a 6.0ltr with 4" bore vs. a 3.78 bore for the 5.3.

A 4.8 shares the same bore as 5.3 but a smaller stroke.

Gen 3/4 5.3s, 5.7s, 6.0s, and 6.2s all have a 3.622" stroke, and the bore keeps growing from 3.78" to 3.9" to 4.0" to 4.06" respectively.

[93Polo]

I like the dyno results and have been researching a 5.3 truck block build as they can be found cheap. Very intersting build with the piston swap.


This makes me want to junk the gen 1 and build one of these engines. I did price the pistons at work for the 4.8 stock pistons and they are a little pricey. It would be different, but dont tell the wife.
Another option maybe to buy a 4.8 take out motor and find crank and rods from a stroker build. I am not sure what length the 5.3 rods are and if they are the same as the other motors that share the same stroke listed above. You can get the 3.622" stroke crank from several motors. Also be sure the reluctor is the same count as the PCM.

Another option for saving some money would be porting the early truck 4.8/5.3 heads. They flow really well when ported. I have a set of stg 2s from http://www.totalengineairflow.com/ on my ls1 that made 436rwhp/415rwtq running a Futral 228/230 112+4, LS6 intake and stock 78mm TB that had been polished up. You would give up some power compared to the TFS heads which are very nice but it would be a heck of a bang for the buck. The 1.5 with a stock exhaust valve actually flow better than the stg 2s.

The 4.8/5.3 heads were the casting most used before aftermarket castings came out. They flowed better when ported than the Ls1 heads and were cheaper than the 243 castings from the LS6. 243 (ls6/ls2) and 317 (lq4/lq9) flowed better were normally bigger budget.

Ls1tech has all the casting #s in their FAQs.

[93Polo]

Steve, What size primaries were used on the headers. I apologize if I missed it. Great tq for a little motor.

[Samckitt]

Steve will the lq9 flat pistons work as well? is the reason the 4.8 were listed is for budget build?

The LQ9 is a 4.0" bore, the 5.3 is a 3.78" bore.

[19,69camaro]

This may sound like a dumb question and I apologize if it is but if I was to go for a budget 4.8, 5.3 or 6.0 build what would be the best donor Im not looking for crazy numbers just a even 350/350 would be fine. Ohh and aluminum is a plus trying to loose some front end weight. Also would like to mate it with a t56 any ideas it would appreciate it.

[Samckitt]

If I was looking for an LS motor (which I may do here soon) I think I would look for an LQ9 or an LY6. According to the latest Chevy Hi Po magazine, the LQ9 can be found in 02-06 Escalades, 03-07 Silverado SS & Sierra. Rated at close to 350 hp & 380 lb-ft. LY6 can be found in 07+ 3/4 ton Silverado, Sierra, Suburban and Yukons. Rated at 352 hp & 382 lb-ft.

Then I probably wouldn't be able to leave well enough along & I would get a 4" stroke crank & drop in to make a 402 ci engine.

[93Polo]

If I was looking for an LS motor (which I may do here soon) I think I would look for an LQ9 or an LY6. According to the latest Chevy Hi Po magazine, the LQ9 can be found in 02-06 Escalades, 03-07 Silverado SS & Sierra. Rated at close to 350 hp & 380 lb-ft. LY6 can be found in 07+ 3/4 ton Silverado, Sierra, Suburban and Yukons. Rated at 352 hp & 382 lb-ft.

Then I probably wouldn't be able to leave well enough along & I would get a 4" stroke crank & drop in to make a 402 ci engine.
If you're building a 402 don't forget the LQ4. The LQ4 is just about the same motor as a LQ9 except for piston dish both were iron block 6.0s with 317 heads unless the LQ9 changed late in the run. You could always swap to smaller chamber heads later on if you wanted more compression on a stock shortblock build.

[pjku79]

This seems to have been dead for a few years. Are people still doing this on budget builds? What are the down sides?

I have a guy at work that has been trying to sell me an engine and he has a 4.8 and 2-5.3 engines in pieces right now. I could use the stock 5.3 with 4.8 pistons, ls6 cam, and yellow springs.

Should be able to get the whole thing for $650. Keep in mind he tears down to inspect then rebuilds if everything looks good.

[hifi875]

I have a 5.3 w milled z06 heads custom cam 218/222. 595/598 lift. In my camaro. Runs good.

[DroptopJ]

Those are some awesome numbers for a 5.3L

[austindub]

Great numbers for a 5.3, but I have to ask the question... why a 5.3? Unless you just had an aluminum 5.3 laying around why not start with an iron 6.0 if you are going to go with aftermarket heads, change the intake, accessory drive, etc.? Either way, that motor looks pretty sharp and makes awesome power!

[trex1270]

I took a 5.3, punched to 5.7 using a torquer V2 on 112, carbed with PRC heads with a holley 750 ultra double pumper, put 420 to the tires with a manual...I figures 526 at the crank..oh yeah 10.8 compression.

[pjku79]

Because 5.3 are about $500 cheaper (iron to iron at least)

[pjku79]

This seems to have been dead for a few years. Are people still doing this on budget builds? What are the down sides?

I have a guy at work that has been trying to sell me an engine and he has a 4.8 and 2-5.3 engines in pieces right now. I could use the stock 5.3 with 4.8 pistons, ls6 cam, and yellow springs.

Should be able to get the whole thing for $650. Keep in mind he tears down to inspect then rebuilds if everything looks good.


Any comments to my message above?