how much gain with a cam swap?

[trbojo]

with the combo listed in my sig., how much h.p. increase and e.t. drop could i expect with a cam swap, and what is a good reccomendation for one? i had plans of doing heads and cam this winter, but at the very least will do the cam if it will be a noticeable improvement.

 

[trbojo]

ttt

 

[don86T]

This spring I went from a stock cam to a 204 -214 cam. Returned to the track with the same boost and about the same weather as last fall. The results were exactly the same as last fall.

This was with a TA 49, home ported heads, big neck intercooler and 2800 D5 converter.

I'm sure others have had better results but I wasn't impressed.

Don

 

[rodman99999]

I'm in the process of rebuilding my engine(just finished tearing down yesterday, and found a wiped lobe), and have the same question. If I have my facts straight: Some cams are designed to give more oomph in the bottom of the power curve, and some to extend the RPM limit(breathe better/give more torque at the top). With the latter, to realize a gain in the 1/4, you'd have to change your shift points and probably launch at higher RPM. We have a narrower power bandwidth to work with than say a Chevy, being our engines/computers don't care for more than 5900RPM(with a mostly stock combo anyway). HP is a function of torque and RPM, so it's easier to get big numbers if you have higher RPM/more cubes(like that SB Chevy). SO: we're faced with always getting the max exhaust flow to the turbo(our source of HP), and balancing that with huffing enough fuel/air through our narrower powercurve. Since moving air is what cams are about, everything before the intake and after the exhaust valve have to be big enough to support flow too, or you wasted your money/time. It seems getting the lobe separation/overlap and duration just right for these puppies has been a mix of science, magic and art for the last 18 years. I could be all wet-but, I think I've got most of that right.(AT LEAST- What I've said should generate some more input on this thread anyway!) Help me get my thinking straight, and make some cam suggestions guys!! Thanx

 

[Cheeseburger]

with the combo listed in my sig., how much h.p. increase and e.t. drop could i expect with a cam swap, and what is a good reccomendation for one? i had plans of doing heads and cam this winter, but at the very least will do the cam if it will be a noticeable improvement.

Do not change cams untill you are ready for consistant 10 second performance.
Stock cam and good valve springs and a bone stock motor was good for consistant bottom 11s for me, and a huge amount of fun!

 

[Ormand]

Going to a roller cam- either hydraulic or solid- will let you pick up a little power, as well as get rid of the possible "wiped lobe" that plagues some cams. The roller will let you have more lift without going to long duration, and will open the valves quicker, giving more flow at reasonalbe rpm. Like rodman pointed out, the stock Buick engine isn't good for super high rpms, so you don't want or need a 7,000 rpm cam. But a roller, with peak power somewhere near 6,000, would probably buy you at least a few horsepower, on top of the better efficiency from lower friction.

 

[CraigT]

I got the advertised .15 sec and 1.5 mph on a 200 cam back in 1993. Same 60 ft and the same summer humid weather in Fl. Went 12.93 @ 105 on 93 gas.

 

[Quick6'n'-K.C.]

As cheeseburger said, dont replace it unless its broken...

Lots of people running low 11s with a stock cam, aftermarket cams will not last as long as the stocker.... i know this.

buy a alky kit or intercooler or something that is easier to do in a few hours
BW

 

[Grumpy]

if it ain't broke leave it alone !!

 

[rodman99999]

WELL- Mine's broke!! Doesn't anyone have any suggestions on a good cam for the street/track, with a set-up like mine? Has anyone used Poston's 107 or 110T? Didn't mean to highjack your thread TRBOJO, but maybe we can use the same answer!

 

[corsair231]

I had a Poston's 107 in my 87 daily driver. It was put in after a fresh rebuild. Developed a burp and power died off after a couple of months. I thought I had a collapsed lifter so I pulled it apart and I had wiped two lobes. I don't know if it was the cam itself or if I had too much lifter preload. I didn't check it. Didn't know better then but after this learning experience I do now. Anyway, the car ran great with it until then. It seemed more responsive and stronger but the engine had been worked so I can't say it was just the cam. I did some research on the Buick sites and several people recommended the comp cams 206. (Except comp cams who recommended their 212 ). But since I am running stock stall I wanted good street manners and everyone I talked with said the 206 was a good choice including an article in GMHTP. I got mine from John's Performance Parts. Talked to John himself, seems like a super nice guy, and got a fairly decent price. I haven't fired it up yet but it's almost ready to drop back in.

 

[rodman99999]

Hi CORSAIR- I'm assuming you replaced the lifters, so how many pounds were the springs? Has anyone else had a Poston's cam wear out really quickly? I'm not into pulling my engine apart every season. Postons's been around along time(so has comp cams). You'd think they'd know what they were doing. I wonder who's making their cams? Did you get all the parts from Poston for that build? thanks for the insights.

 

[corsair231]

Yes, I did replace the lifters. They were the hi-rev lifters offered by Poston's. The springs were the stock LT-1 95# springs that everyone runs. I think the problem I had with lifter preload was due to surfacing the block and heads. The machinist was just supposed to true them up but may have decked them thus reducing the installed height of the rocker shaft. The forged pistons and rings came from summit. The springs and bearings came from the machinist because he prepped and clearanced everything. I like Poston's and have nothing against them and will use them in the future but due to my problem I chose to go with another cam manufacturer, just in case . I'm not sure and I may be wrong, but I think someone said that Poston's cams came from a manufacturer in Canada.

 

[rodman99999]

Canada, huh? The way those hosers hate us, maybe they're sabotaging our cams now?(probably was that shaving on the heads and block though) I'm really leaning towards that Comp 212/212. I've read alot of good stuff about it in here. It's cheap at Jeg's too!

 

[WHEEZER]

I went with a 205/205 Reeds. It has a really strong low and mid range "seat of the pants" which is exactly what I wanted. I only do 1/8's and quick Chevy, Ford and Beemer kills on the street. :biggrin: