Next project - 402 or 418 stroker - piston question
07-08-2014, 02:48 PM
#1
Next project - 402 or 418 stroker - piston question So, I am already starting to plan my next build with either an LS2 or LS3 block. The price difference is pretty minimal and generally speaking, the LS3 is probably the best bang for the buck block available.
However, I would like to reuse my TEA Stage 2 LS6 heads, have them opened up to maybe 65cc (don't think I can go much bigger than that), and have 2.055" or larger valves installed along with some hand porting and anti-detonation tricks done to the chamber. I think for my goals of a pretty strong 402/418 with 530+rwhp the heads will achieve it.
My question is around the pistons themselves. I've seen a lot on flat top vs dish pistons and I'm not real sure if there is much difference in an NA build as long as the dish pistons have a quench area. But is there much difference? Would running high compression with the dish be bad for knock vs running the flat tops?
I am looking at 12.1:1 with the 402 and Flat Tops with 2cc valve reliefs and about 12.5:1 with the LS3 using my heads with a quench of around .035". And yes, yes, I know, sell them and get LS3 heads. And the answer is no. I invested in these heads with the intent to move to a 402/416 down the road and give me great throttle response and usable torque/power.
Given the compression I'm looking at because of the heads smaller chamber size, does it make more sense to do the 402 or 418 with that much compression and flat tops? Or will the dish hurt anything? Right now I'm leaning to the 402 as the 2.055" valve would work better there and provide 12.1:1 compression, which is good for 93 with the cam I intent to use... an EPS 248/254 .625"/.620" 111+3. 12.5:1 might be pushing it...
If the dish will work okay, getting some 8cc dish pistons will get the 418 down to 11.6:1 or so, which will be more than fine with 93.
Any thoughts? Plan to reuse my Kooks 1-7/8" and True Duals as well as the ported FAST 102.
However, I would like to reuse my TEA Stage 2 LS6 heads, have them opened up to maybe 65cc (don't think I can go much bigger than that), and have 2.055" or larger valves installed along with some hand porting and anti-detonation tricks done to the chamber. I think for my goals of a pretty strong 402/418 with 530+rwhp the heads will achieve it.
My question is around the pistons themselves. I've seen a lot on flat top vs dish pistons and I'm not real sure if there is much difference in an NA build as long as the dish pistons have a quench area. But is there much difference? Would running high compression with the dish be bad for knock vs running the flat tops?
I am looking at 12.1:1 with the 402 and Flat Tops with 2cc valve reliefs and about 12.5:1 with the LS3 using my heads with a quench of around .035". And yes, yes, I know, sell them and get LS3 heads. And the answer is no. I invested in these heads with the intent to move to a 402/416 down the road and give me great throttle response and usable torque/power.
Given the compression I'm looking at because of the heads smaller chamber size, does it make more sense to do the 402 or 418 with that much compression and flat tops? Or will the dish hurt anything? Right now I'm leaning to the 402 as the 2.055" valve would work better there and provide 12.1:1 compression, which is good for 93 with the cam I intent to use... an EPS 248/254 .625"/.620" 111+3. 12.5:1 might be pushing it...
If the dish will work okay, getting some 8cc dish pistons will get the 418 down to 11.6:1 or so, which will be more than fine with 93.
Any thoughts? Plan to reuse my Kooks 1-7/8" and True Duals as well as the ported FAST 102.
07-08-2014, 09:11 PM
#3
418 w/ TEA STG2 243s is my goal too. should be a torque monster.IMHO
07-08-2014, 09:56 PM
#6
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Jake, I was where you are a year ago. Truthfully, when you look at all the cost, the difference between a forge built 402/416 and an ERL/RED sleeved block build is less than 1k. I came to the conclusion that if the difference between me being satisfied with a 402/416 or me being thrilled with an LS7 headed big bore monster was only 1k, I was going to do it! So I did, it. Now, that was me going with new heads on either build, but still, bottom end difference isn't that different.
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07-08-2014, 10:41 PM
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Your splitting hairs..if the quench is right and you get the desired compression... No difference flat-top VS dish, or better yet a Concave piston from Wiesco: somthing I learned from: S.A.M. 434ci SBF.
Also JE's new design is the bomb. Lighter & stronger VS others..= 2more HP.
You need 7500 on the spot 2 talk your way out of ERL with a shortblock. Every1 can't start @ that price level. With factory parts any1 can have 400-1200 hp from nothing other than common sense.
Also JE's new design is the bomb. Lighter & stronger VS others..= 2more HP.
You need 7500 on the spot 2 talk your way out of ERL with a shortblock. Every1 can't start @ that price level. With factory parts any1 can have 400-1200 hp from nothing other than common sense.
Last edited by lil john; 07-08-2014 at 10:55 PM.
07-08-2014, 11:01 PM
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427 I don't want 2 seem rude but if we were 2 do a cost to HP ratio...on pump gas my
LQ9 stroker with Frankenstien LS3 heads & a solid roller was Dirt cheap well under 7000 grand and I bought every part, also... I will not take Anything less than 700fwhp under 7500rpm or this was just a USE-LESS BUILD.
LQ9 stroker with Frankenstien LS3 heads & a solid roller was Dirt cheap well under 7000 grand and I bought every part, also... I will not take Anything less than 700fwhp under 7500rpm or this was just a USE-LESS BUILD.
Last edited by lil john; 07-08-2014 at 11:08 PM.
07-09-2014, 05:41 AM
#15
And yes, yes, I know, sell them and get LS3 heads. And the answer is no. I invested in these heads with the intent to move to a 402/416 down the road and give me great throttle response and usable torque/power.
In the end you will probably spend the same and have some killer heads (not that worked TEAs are not) that will provide all the throttle response and usable power you want.
07-09-2014, 06:11 AM
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Well Redtan Y in the hell did a pair of stock ported heads do just as well as Mast Heads on the Hot Rod 408...
Every1 thinks that spending more is better...... if the port is bigger than a aftermarket port a good cam will level the playing field.
OK try this. My engine has 2 pair of heads. TFS 255 bare 1050 .oo each = 2100 + tax.
My 823 casting cost 175.oo ea and 1100.oo for porting... Now can you help me? Will both reach a goal of 500-700 hp? Both heads will but @ what cost....
The factory has all that is needed, the Aftermarket just charges you for a Tweaked product of a factory part...255cc 12 degree LS3 VS stock 15 degree 260cc .. Cnc makes either 1 shine...
Every1 thinks that spending more is better...... if the port is bigger than a aftermarket port a good cam will level the playing field.
OK try this. My engine has 2 pair of heads. TFS 255 bare 1050 .oo each = 2100 + tax.
My 823 casting cost 175.oo ea and 1100.oo for porting... Now can you help me? Will both reach a goal of 500-700 hp? Both heads will but @ what cost....
The factory has all that is needed, the Aftermarket just charges you for a Tweaked product of a factory part...255cc 12 degree LS3 VS stock 15 degree 260cc .. Cnc makes either 1 shine...
Last edited by lil john; 07-09-2014 at 06:18 AM.
07-09-2014, 08:14 AM
#17
In theory, a dish or concave piston is better because it acts sort of like a catchers mitt for the flame propagation. Whether or not that translates into handling higher cylinder pressures for a given octane, I don't know. Personally, I would keep the compression down to about 11.8:1 max for 93 octane and keep a margin of safety. More than that, and I would consider E85.
07-09-2014, 08:19 AM
#18
Jake, I was where you are a year ago. Truthfully, when you look at all the cost, the difference between a forge built 402/416 and an ERL/RED sleeved block build is less than 1k. I came to the conclusion that if the difference between me being satisfied with a 402/416 or me being thrilled with an LS7 headed big bore monster was only 1k, I was going to do it! So I did, it. Now, that was me going with new heads on either build, but still, bottom end difference isn't that different.