who has tried a cam with less than a 110 LCA/ICL and less than 216 duration? Any dynos?

 

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You are probably familar with Bret Bauer (SStrokerAce). He did a camshaft for a guy who has this 402 w/ Dart heads and a valve job. The cam that the customer was using before hand was your typical 242/248-112. I can't say for sure, but from what I gather Bret uses a lot of tight LSA profiles for his customers setups. After questioning Bret on this particular setup, he told me I was aiming in the right direction.

I wrote : Any more hints on what you did with the cam? If duration was smaller, I'd have to guess the LSA was tightened to increase overlap for the new cam. No? Just a guess based off of how the same peak HP numbers were met.

In the dyno below, you'll see how average power was increased and peak numbers were also met. Basically what he did was shrunk the duration and tightened the LSA which created an overall better package as TQ was increased across the graph. Now relate that to your VEs and you'll get what is going on.

The dyno

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I'm kind of shy to give you results on my old 214 profile. Something was wrong. This cam and the one I had cut for my dad's C5Z both used SBF/SBC lobes out of the Comp catalog. On both of our cams, I used Ford on mine and Chevy journal sizes on the intake lobes. Results? Both cams are real finicky on the bottom end. I had a 226/224 profile cut for a friend's truck and the torque curve was amazing. The difference between my dad's cam and the 226/224 profile was the intake lobes journal size. When you order a cam you can have it on a R journal (LS1), F jounral (SBF), S journal (SBC), B (BBC), etc. What this does is change the cam specs... They either shrink or grow... usually growing when you put them on a R because of the larger journal of the LS1.
... Basically, I'd hate to give you feedback on my old cam incase there actually was a problem. That would be really misleading.

 

do you have the specs before and after on that cam?

I appreciate your honesty on your cam. I was planning on just using both xe lobes on a 55mm journal, Id like xfi but worry about my 918's with 32k miles on em plus the heads have 50 off and Im running bigger valves.
Thats got to wreak havock on your valve train geometry with different lobes. That might have been part of the problem with different amounts of preload or causing a bouncing effect when the valve seats(just thinking out loud).

I see what your saying on shrinking the lsa/icl and duration it keeps overlap in the same spot but shuts the IVC earlier=more tq and the EVO=decreases.

Thats one thing Im wondering about is dropping the EVO, Id like to open it earlier but obviously duration goes up. You can run an exhaust bias but to an extent the bias will hurt low end. I figure there has too be a medium. Ive been reading a book by Vizard where he says blowdown from exhaust bias can hurt low end by as much as 5%.
Im interested to see the specks on the two cams from brett.

 

I'd guess it would be something like this for us....
222/224 XE 112LSA 108ICL vs. 214/216 XE 108LSA 108ICL
Try what you have planned. It should work fine. The biggest pain is the amount of RPM you are going to have to cover with that stock converter.

I'm sorry, which one?

 

You were saying he was using a 242/248-112, then bret dropped the duration and lca/icl. What were the after specs?

 

He didn't release them. I only made the assumption that the duration decreased and LSA/ICL was narrowed based off of the dyno graph and he stated that those were the correct steps.

 

[QUOTE=Sport Side]The biggest pain is the amount of RPM you are going to have to cover with that stock converter.[QUOTE]
Thats what Im worried about Id rather shoot for off idle than have it bog down low.

 

I think I found the Holy Grail. It's a Crane Cam specs out at .525/.525 200I and something like 208E at .050". It's a 112LSA. I was looking to add a litle punch down low in my 5.3................