110º or 112º lobe seperation opinions???

[Lee Thompson]

cam

I was talking about the 208-224

 

[turbo buicks]

lee, hows the idle on that 208-224?

thanks

 

[Lee Thompson]

idle

It seem to me that with the 4.1, the idle was a little more lumpy than with the 3.8.
Overall---just enough difference to let everyone that it was not stock. My chip idles at 850 so that could make a difference.

 

[turbo buicks]

what about cutting the valve guides down to fit the lift of the cam, did you have to do this on the 3.8 to "fit" the 208-224.

 

[Lee Thompson]

valve guide

My heads were already done. Yes that is something that you will have to watch for especially on the exhaust side. Forgot that!! Some of these after market springs can be installed @ a taller height than the stock 1.727 Mine were @ 1.750

 

[turbo buicks]

will the edelbrock 204-214 cam w/CC980 springs work fine on stock heads

 

[Intercooler]

Originally posted by turbo buicks
will the edelbrock 204-214 cam w/CC980 springs work fine on stock heads

I do believe. I think over .480 lift you need to have it checked. My heads had to be cut to fit the .532 lift roller.

 

[HRpartsNstuff]

I put a cam in mine back in 96? I believe it was. They were just getting into cams over the "club" 200/200 cam for stk converter street use it seemed. Me being one to always press the rules & envelope, I got a custom grind from Comp Cams. It was their standard 262 or 268 cam (not sure now) that had 206* @ .050 int/exh. It was normally on a 112 c/l, but I had it done on a 108 c/l. I had always heard that it gains a bunch of power low/mid, without sacrificing much if any on the top end. But the real reason was:

The tighter (lower #) the c/l, the more overlap it will have. To me, that meant the boost on the intake would send more fresh air in to replace the exhaust gasses that might not have got out before. Kinda like flushing it out better so a cleaner charge for next combustion. Another gain was that it sent some extra fuel out the exhaust, which burned there & made the boost come up faster & allowed it to go higher.

Bottom line, my car idled fine, VERY streetable. It may have been a bit smoother with 110 or 112 c/l, but sure didn't need to be. With a 3000 stall converter, I could bring it into the lights at 0 boost, stage, mash it, & the boost would come up faster than the tach. Once it went over 20, I would let it rip! It pulled hard to around 5350, but I had stk heads slowing that down a bit I'm sure. Biggest problem was I couldn't tame it down on boost for pump gas easily. It always wanted to boost up to 22 psi min. Probably needed a bigger wastegate hole too. Loved it. I would go with the 110 in your case, good comprimise & should idle fine.

I also like the straight patterns to myself. At max boost, you have a boat load of pressure in the exhaust side. To let the exh valve stay open longer is not as beneficial as you would think. There is a point where the exh gasses won't push out against the pressure in the exh. The reason the dual patterns might help is that the extra duration actually increases the overlap. This is somewhat like changing it from a 112 to a 108 in a way. I would be more worried about the agressive ramps in the design. I could have went with several other "grinds" that had a much faster ramp speed that would make more power. I went with the milder grind to ensure it would last. You can compare the advertised & the duration at .050 to see if one grind is quicker than another. I would rather add a pound of boost to get more air in than to do it with an aggressive cam profile.

Just some more thoughts & ramblings for you to consider

 

[turbov6joe]

Paul,
Thanks for sharing your thoughts on this subject. After much deliberation on my part, I decided to go with the Comp Cams
212-212 on a 112º LS and a matching lifter set. Although I really don't want to mess with breaking in a new cam, it seems such a waste not to replace it while I'm SO far into the motor this winter. I figure the extra HP I see from this cam should offset my switching from drag radials to mushy slicks
My goal for this car was to leave it as close to stock as possible, but y'all know how that goes when I was bit by the "gotta go faster" bug some 12 years ago when I picked up my first LC2 car. I did however make the final decision to not touch the block internals untill something lets go on its own. I was going to change out all the fasterners and bearings, but decided to leave'em alone for now. I'm curious to see how long the "If it ain't broke...don't fix it" motto lasts with this motor??? I finger that the lift on this new cam, coupled with the 1.65 ratio of the rockers, should prove to make some serious HP at 26+ psi...
Come spring 2003 when the local track opens, I'll prolly get to make 4 passes before they throw me out on my duppa for not having a rollbar in my mint TTA Oh well, I don't really need to go that fast anyhow....NOT!