New engine project nearly done and ready for tuning
06-11-2017, 05:24 PM
#22
Burning Brakes
Right on, I’ll post up a full bolt on vs. previous head/cam setup, and the H/C vs. the current 402.
As all dynos read differently, so I feel it would add more accurate data points knowing how different components affected the hp/tq on the same dyno.
As all dynos read differently, so I feel it would add more accurate data points knowing how different components affected the hp/tq on the same dyno.
Last edited by HC Mechanic; 06-11-2017 at 05:27 PM.
06-11-2017, 07:54 PM
#23
Burning Brakes
Thread Starter
Very impressive thanks for sharing. What rear tire are you using on the street (mfg., model, size). Any details about the build you would care to share (heads, cam, intake, headers & mufflers, crank & rod mfg. etc.)
I will rely on BT for a more radical cam for the stroker. I asked Spin last year if he had a suggestion and he replied that he had not developed a stroker cam. He also said the 230/234 cam he developed was to small for a LS3 stroker.
I will rely on BT for a more radical cam for the stroker. I asked Spin last year if he had a suggestion and he replied that he had not developed a stroker cam. He also said the 230/234 cam he developed was to small for a LS3 stroker.
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HC Mechanic (06-12-2017)
06-12-2017, 02:48 AM
#24
Burning Brakes
Thanks Brother, can't wait to see what you end up with 
Yes, once you up the stroke your potential flow at low revs is much better, so it opens the door for a much more aggressive cam. I'm not certain on the difference in cam selection on my car, but I know it was quite a bit. The compression is on the edge, I suspect to make the most of a larger cam down low.
The heads are max effort 243's and 102 manifold is port matched to them. The 102 tb ended up being worth 10-15rwhp, so we ditched the stocker. Headers are actually a used LG set from the man Spinmonster himself, of which I was informed came off Lou's race car. So I guess I'm the 3rd owner. Cats are high flow(Random Technologies) and mufflers are from Burns Stainless, the whole system was put together by a Burns Stainless approved fabricator.
Crankshaft came from Molner, wish I could have afforded an American crank. Rods are Carrillo, pistons are custom forged models from CP. I come from road racing background, and I can tell you from experience that CP and Carrillo are on par with the best out there. CP has a very extensive way they machine a piston.
As for the tires, I really appreciate a tire that can corner as well as accelerate, it is a Corvette after all...having said that, I like my new cup 2's a LOT. 315/30/19 / 285/30/18
Yes, once you up the stroke your potential flow at low revs is much better, so it opens the door for a much more aggressive cam. I'm not certain on the difference in cam selection on my car, but I know it was quite a bit. The compression is on the edge, I suspect to make the most of a larger cam down low.
The heads are max effort 243's and 102 manifold is port matched to them. The 102 tb ended up being worth 10-15rwhp, so we ditched the stocker. Headers are actually a used LG set from the man Spinmonster himself, of which I was informed came off Lou's race car. So I guess I'm the 3rd owner. Cats are high flow(Random Technologies) and mufflers are from Burns Stainless, the whole system was put together by a Burns Stainless approved fabricator.
Crankshaft came from Molner, wish I could have afforded an American crank. Rods are Carrillo, pistons are custom forged models from CP. I come from road racing background, and I can tell you from experience that CP and Carrillo are on par with the best out there. CP has a very extensive way they machine a piston.
As for the tires, I really appreciate a tire that can corner as well as accelerate, it is a Corvette after all...having said that, I like my new cup 2's a LOT. 315/30/19 / 285/30/18
06-12-2017, 08:58 AM
#25
Cool builds guys!
I know nothing about building engines, but I'm curious.
Why did the OP mill the heads 0.30", then add it back with 0.40" head gaskets?
I know nothing about building engines, but I'm curious.
Why did the OP mill the heads 0.30", then add it back with 0.40" head gaskets?
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HC Mechanic (06-12-2017)
06-12-2017, 09:38 AM
#26
I think he's using 0.04" thick gaskets, which are thinner than stock head gaskets, which are ~0.051", iirc.
Last edited by CI GS; 06-12-2017 at 09:39 AM.
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dmk0210 (06-12-2017)
06-12-2017, 10:59 AM
#27
06-21-2017, 05:16 PM
#28
Burning Brakes
Thread Starter
That is correct the stock gaskets are .051 (compressed and the Cometic's are .040). This motor has stock pistons so the stock pistons had to have valve reliefs cut on the intake side for adequate P/V clearance. All this was covered in detail by Spin in his original posts concerning using his 230/234 cam and raising the stock compression ratio. Those threads have disappeared off the site for some reason.
Last edited by jstewart; 06-21-2017 at 05:18 PM.
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dmk0210 (06-22-2017)
08-14-2017, 01:23 PM
#29
Tech Contributor
Great results.
08-14-2017, 01:43 PM
#31
Tech Contributor
CI GS the cam specs on the custom BT cam are:
intake lobe--13097, intake duration--229, IVO-4, IVC-44.5
exhaust lobe--3655, exhaust duration--244, EVO-60, EVC-4
LSA-114+4
Jason I don't know if BT has used this spec cam before. I filled out a custom cam request form from him which listed all the engine specs and gave BT the specs on you're cam. I asked him to give me a cam that would make more HP while sacrificing as little low end and drivability as possible. I went to his shop with the form and he came up these specs in about 5 minutes of study. After the car was tuned at Shore Tuning I asked the owner & tuner at Shore tuning, who works pretty closely with BT, if he thought the custom BT cam would gain additional HP & TQ. Based on the dyno pulls and results he recommended I leave the 230/234 in the car unless I increased the displacement with a stroker crank.
intake lobe--13097, intake duration--229, IVO-4, IVC-44.5
exhaust lobe--3655, exhaust duration--244, EVO-60, EVC-4
LSA-114+4
Jason I don't know if BT has used this spec cam before. I filled out a custom cam request form from him which listed all the engine specs and gave BT the specs on you're cam. I asked him to give me a cam that would make more HP while sacrificing as little low end and drivability as possible. I went to his shop with the form and he came up these specs in about 5 minutes of study. After the car was tuned at Shore Tuning I asked the owner & tuner at Shore tuning, who works pretty closely with BT, if he thought the custom BT cam would gain additional HP & TQ. Based on the dyno pulls and results he recommended I leave the 230/234 in the car unless I increased the displacement with a stroker crank.
The cam above has an 8.5 overlap vs 4 degrees for my cam.
Big splits came about because people thought the lower head CFM meant bad flow when in fact is was just a higher velocity. Extending the exhaust side duration came about to make up for people's belief that it would help a poor flowing head. On comp's website and if you do a general search on Google (I searched exhaust duration torque) shows that extending the exhaust duration too much hurts low end Tq. I guess it is a balancing act.
Too bad you didnt use the cam and overlay the two graphs. I think it would have been a good read as to how much it helps or hurts. My cam is a great balancing act with crazy high end Tq. I've seen a ton of cams make near the same power but why have more overlap? FWIW I also used a 230/230 114 and it was 3hp lower which is dyno variance. Selling people on a single pattern cam here is like like trying to sell ice to a penguin. I use it on automatics because it is 2 degrees overlap.