Will I break 500rwhp?
12-16-2018, 03:03 PM
#1
Will I break 500rwhp? Reworking my c5z due to low oil pressure. Current build did 445/440 (404 ls2 stroker, worked 243 heads, unknown cam, 1.75 kooks, fast 90/90.) was pretty impressed when I was sold the car as I was told it was an ls6. After loosing oil pressure a week after buying it, and then finding out it was a stroked ls2... those numbers were pretty weak.
I’m thinking previous cam had ivc way too soon for stroker (dyno graph kinda confirms this with super early power band), and heads were too small and milled too much for a stroker (measured at .035
New recipee is 405 stroker (4.015 bore je asymmetric pistons), same 6.125 lunati I beam rods, same eagle 4” crank, prc 227 heads, cam motion 238/252 114+3, ported fast 102/ 90mm tb, tsp 1.72 roller rockers, same 1.75 kooks, 11.8 to 12:1 comp, 10% ati crank pulley, Johnson 2126st axle oiling lifters, improved racing crank scraper, 11/32 pushrods
really shooting for 500/500rw with a tq curve that doesn’t fall off after peak. Any last minute changes I should consider?
I’m thinking previous cam had ivc way too soon for stroker (dyno graph kinda confirms this with super early power band), and heads were too small and milled too much for a stroker (measured at .035
New recipee is 405 stroker (4.015 bore je asymmetric pistons), same 6.125 lunati I beam rods, same eagle 4” crank, prc 227 heads, cam motion 238/252 114+3, ported fast 102/ 90mm tb, tsp 1.72 roller rockers, same 1.75 kooks, 11.8 to 12:1 comp, 10% ati crank pulley, Johnson 2126st axle oiling lifters, improved racing crank scraper, 11/32 pushrods
really shooting for 500/500rw with a tq curve that doesn’t fall off after peak. Any last minute changes I should consider?
12-16-2018, 04:18 PM
#2
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I would go to larger primaries and def go 102mm. I think you may want larger heads too. Something like AFR 230
12-16-2018, 04:21 PM
#3
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Looks good, except for the cam IMO 14* exhaust split not needed with Aftermarket
cathedral Heads. Even with 1 3/4 LTs + 6-8* should be plenty with your exhaust and will
drive much better. Something like 238/246 114*+3* but contact Cam Motion ... or
your vendor of choice. You should clear 500 RWHP comfortably.
Also use VMax TB Spacer with 90 MM TB with FAST 102 Intake.
I agree with Darth AFR 230s & 1 7/8 LTs would add ~25 to your combo
if in the budget.
cathedral Heads. Even with 1 3/4 LTs + 6-8* should be plenty with your exhaust and will
drive much better. Something like 238/246 114*+3* but contact Cam Motion ... or
your vendor of choice. You should clear 500 RWHP comfortably.
Also use VMax TB Spacer with 90 MM TB with FAST 102 Intake.
I agree with Darth AFR 230s & 1 7/8 LTs would add ~25 to your combo
if in the budget.
Last edited by NAVYBLUE210; 12-16-2018 at 04:26 PM.
12-16-2018, 05:25 PM
#5
Correction on the headers they are 1 7/8. Autocorrect got me. Also already have the vmax ring mentioned
was using the prc227 because #1 I got a hell of a deal for them, and #2 reading up on the intake flow threads, I didn’t think I could use all of the flow out of those heads now. As in I’m already intake manifold limited to 300cfm
was using the prc227 because #1 I got a hell of a deal for them, and #2 reading up on the intake flow threads, I didn’t think I could use all of the flow out of those heads now. As in I’m already intake manifold limited to 300cfm
Last edited by bthomas; 12-16-2018 at 06:24 PM.
12-16-2018, 06:41 PM
#6
Correction on the headers they are 1 7/8. Autocorrect got me. Also already have the vmax ring mentioned
was using the prc227 because #1 I got a hell of a deal for them, and #2 reading up on the intake flow threads, I didn’t think I could use all of the flow out of those heads now. As in I’m already intake manifold limited to 300cfm
was using the prc227 because #1 I got a hell of a deal for them, and #2 reading up on the intake flow threads, I didn’t think I could use all of the flow out of those heads now. As in I’m already intake manifold limited to 300cfm
12-17-2018, 08:46 AM
#7
FWIW - pI'd go bigger than a 227 cc head on a 404. The 227's are nice for an LS1, good for a LS2 or OK for a 383 LS1 stroker but a 4 inch bore 404 will want more airflow than those engines.
If the PRC 227's flows ~ 310 cfm, (I don't know what the head flows) the 102 Fast will reduce peak flow of the cylinder head by probably ~15 to 25 cfm leaving about ~ 290 cfm of air flow.
ROUGH rule of thumb the LS2 404 stroker at ~ 6,500 rpm will want about 320 cfm of air flow for best power.
I think someone mentioned Darin Morgan used this formula for basic airflow required as a rough estimate.
CFM = (CID x rpm x .000978474)/8
CFM =(404 cid x 6,500 rpm x .000978474)/8 = 320 cfm
So as the others mentioned, I would want the bigger 237 PRC heads for the 404 stroker. They will probably flow a little more air with the 102 Fast intake and feed the 404 stroker better than the 227's.
If the PRC 227's flows ~ 310 cfm, (I don't know what the head flows) the 102 Fast will reduce peak flow of the cylinder head by probably ~15 to 25 cfm leaving about ~ 290 cfm of air flow.
ROUGH rule of thumb the LS2 404 stroker at ~ 6,500 rpm will want about 320 cfm of air flow for best power.
I think someone mentioned Darin Morgan used this formula for basic airflow required as a rough estimate.
CFM = (CID x rpm x .000978474)/8
CFM =(404 cid x 6,500 rpm x .000978474)/8 = 320 cfm
So as the others mentioned, I would want the bigger 237 PRC heads for the 404 stroker. They will probably flow a little more air with the 102 Fast intake and feed the 404 stroker better than the 227's.
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12-17-2018, 03:33 PM
#8
I think you'll do over 500. For an example..
I put together a car for a buddy out of parts he had laying around. Pretty much all of the stuff he had was used and he wasn't 100% sure on all specs which really sucks when trying to build something for someone and they don't know much about what they give you to build the car with, anyway the cam was a bit smaller than what you're using and probably over 10 years old so the cam tech wasn't what it is now. It was around an 11:1 compression car. Had a 406 stroker, PRC 2.5 heads (used to be 243 heads?). A fast 102, 4L60 with an unlocked 3600 converter with a 12 bolt and it did 497 to the tires. It wasn't stellar but it was using cathedrals, and a bunch of questionable parts lol so it wasn't horrible either. Your list is a little better so I would imagine you'd do a little better. Even with the undersized heads. That and I'm assuming you'll be using a manual trans since it's a c5z.
All that being said, can you safely take an LS2 to 4.015?
I put together a car for a buddy out of parts he had laying around. Pretty much all of the stuff he had was used and he wasn't 100% sure on all specs which really sucks when trying to build something for someone and they don't know much about what they give you to build the car with, anyway the cam was a bit smaller than what you're using and probably over 10 years old so the cam tech wasn't what it is now. It was around an 11:1 compression car. Had a 406 stroker, PRC 2.5 heads (used to be 243 heads?). A fast 102, 4L60 with an unlocked 3600 converter with a 12 bolt and it did 497 to the tires. It wasn't stellar but it was using cathedrals, and a bunch of questionable parts lol so it wasn't horrible either. Your list is a little better so I would imagine you'd do a little better. Even with the undersized heads. That and I'm assuming you'll be using a manual trans since it's a c5z.
All that being said, can you safely take an LS2 to 4.015?
01-15-2019, 04:19 PM
#15
Slight update on parts list. TEA is cutting me some ls3 hollow stem intake valves, also was able to get a 102mm Tb, halltech 102mm intake bridge (will convert to card maf), and D585 coils to up spark a hair.
I plan on getting a maf honeycomb and a 4.5” intake filter to go with the new air bridge.
I plan on getting a maf honeycomb and a 4.5” intake filter to go with the new air bridge.
