LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Hitting 400rwhp NA in an LT1

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Old Feb 19, 2004 | 06:30 PM
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Question Hitting 400rwhp NA in an LT1

In a few weeks I will be strapping on some fully ported 195cc AFR LT4 heads. I have longtube headers, Corsa, K&N, etc. I want to hit 400rwhp minimum. I have a 225/232 Crower cam, but I've done some research and question asking and the consensus is that I'm unlikely to hit 400rwhp with that cam. I am considering upgrading to one of two cams: Comp 230/236 or 233/239 (ground by Combination Motorsports).

Questions:
1. How high will the 230/236 and the 233/239 rev to, respectively? I would like to avoid running my motor past 6700rpm.

2. This is my daily driver. Drivability is a concern. Obviously, the 230/236 should idle better than the 233/239. I have 4:11 gears and would be happy with either cam if I could go up and down the road comfortably at 60mph in 6th gear (~1900rpm). Is this reasonable for the cams?

Any additional input would be appreciated.
Old Feb 19, 2004 | 06:52 PM
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The XE 230/236 makes peak power around 6100-6300 rpm.

You might also want to consider a cam from Lloyd Elliot. Around the same duration but they produce more power.
Old Feb 19, 2004 | 06:58 PM
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Kewl. I assume he custom grinds them - for about how much? I've seen a lot about his cylinder heads. Never heard of him making cams.
Old Feb 20, 2004 | 03:12 AM
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Originally posted by Elysian
Kewl. I assume he custom grinds them - for about how much? I've seen a lot about his cylinder heads. Never heard of him making cams.
He now offers cams also. Mainly to match his heads that he ports, but maybe you can get him the flow numbers on your heads and he can get a cam matched up for ya. Custom cams are $400 I believe, but well worth it.
Old Feb 20, 2004 | 09:16 PM
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Anyone with dyno-graphs running the 230/236 or 233/239? Just curious.
Old Feb 20, 2004 | 09:48 PM
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save yourself a bunch of money and go with Lloyd Elliots heads/cam package. For $1100-$1500 you can get your heads ported by him and get a custom cam to match. I have heard of one person in the 425RWHP range with his package, and a couple in the 400-415RWHP area (the cams are still new, not many have them yet)
Old Feb 20, 2004 | 11:30 PM
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You're splitting hairs with 3* of duration - go with the bigger one.

I drove a 235/242 cam with 3.42 gears for a year. Had some surge, but it was only below 40mph 1600-1900rpms. Freeway speeds were just as stock. With your gears, I wouldn't be afraid to go big (over 235 intake).

Ryan
Old Feb 21, 2004 | 02:15 AM
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If you want a custom, custom cam, we do those as well. Nothing off the shelf. Inverse radius, ramps steeper than solid roller stuff. Every cam has it's own master made just for that customer. Dyno numbers have these inverse radius cams making 30+ more horsepower than the similar Comp lobes, but they are killer on the valve train and not worth the trade off for most street cars. Race car? Absolutely. The custom cam system we use was designed by Terry Kell of NHRA and PSCA fame and "Old Man" Jones, who was the lead designer of the legendary Offenhauser Indy engines. Throw Kevin Kroyer in, Winston West engine builder of the year 4 years running and runner up in the Craftsman Truck series (Orleans Racing), I think we've got ourselves a serious resume'. If there's going to be a custom cam horsepower war, count us in.

Also, horsepower is not the be all, end all to speed. It's all about the setup.

p.s. All in good fun, Lloyd is a good friend and all around great guy

Seth

Last edited by cmotorsports.com; Feb 21, 2004 at 02:20 AM.
Old Feb 21, 2004 | 02:23 AM
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p.s. The 233/239 has hit 400rwhp on numerous occasions with various heads, ours, Lloyds, GTP's, etc. It's not too tough with a good setup.
Old Feb 21, 2004 | 08:20 AM
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Thanks for the replies all. Appreciate it.

Quite honestly, I would be perfectly happy just hitting 400rwhp. It may not be the "be all end all," but it's a nice benchmark. This is my daily driver, so going with the more serious lobes you guys were talking about probably isn't worth the tradeoff for me. Was pretty seriously considering the cmotorsports 230/236 .622/.624 112 lsa. I've got 1.5 rockers so the lift wouldn't be so absurd. Any opinions?
Old Feb 21, 2004 | 08:59 PM
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If AI or lloyd was to custom grind a cam to fit your heads and you had hopes of hitting 400rwhp, if they accomplished this with a relatively small cam, would this be able to pass emissions?
Old Feb 21, 2004 | 10:06 PM
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Inverted flank lobes would require regular checks on spring prssures and or spring replacement.. the quick opening time and valve movement wouldnt be suited for a street application or even a street /strip application... the lobes are way to aggressive for anything short of a strip only...CM nice thought ,but not very wise to be trying to promote cams with those profiles for the average street/strip guy out there..Inverted flank lobes have been out for sometime now it isnt anything new...having a aggressive cam lobe is one thing, valve /spring control is another.. the lobes your talking about actually float higher lifts ..common "cam lift rule" class trick used in many classes..But there again not wise for the average racer or anyone going by advertised lift figuring p/v clearance only to find a bunch of bent valves after a hard pull on the dyno..
Old Feb 21, 2004 | 10:21 PM
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Like I said before, some cams are not for the street/strip guy/gal. There is a balance in all cam design, you never EVER gain something without sacrificing something as well in cams. Of course inverse radius cams have been around a while, so has the 2 valve small block chevy...yet there are advancments every hour in both.

Last edited by cmotorsports.com; Feb 21, 2004 at 10:24 PM.
Old Feb 21, 2004 | 10:29 PM
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Yes there sure is,no doubt about that...I wasnt trying to bust up your post..i just think before someone goes to that extreme it would better to run a solid..inverted flank lobes were developed to cheat classes as it were where lift rules were enforced in alot of S/E classes and organizations abroad.Thats pretty ,uch why they were developed in the first place.. Theres power there, but at a price . Attention to springs and tolerances are a must and as you mentioned earlier ..make havoc on valve train parts ..
Old Feb 21, 2004 | 11:21 PM
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Originally posted by magius231
save yourself a bunch of money and go with Lloyd Elliots heads/cam package. For $1100-$1500 you can get your heads ported by him and get a custom cam to match. I have heard of one person in the 425RWHP range with his package, and a couple in the 400-415RWHP area (the cams are still new, not many have them yet)
were did you come across people with this set up ive been trying to find what # people are puting down with this set up but i cant find anyone



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