mando_88iroc-z

i have an 88 iroc-z with a 305 tpi an a t-5 transmission, overhauling the motor soon an want to upgrade the cam while it is already open. the car has is mainly stock few upgrades like k&n filters, bosch platnium 2 plugs, accel cap/rotor, accel 8.8 mm plugs, true dual exhaust with no cat.
i was looking at a comp cam thumpr cam for the choppy idle i desire, but idk if it will fit right or what else must be done??? so any advice on that or any other cam all the advice will be great, thanks....

fireturd350

iTrader: (8)

Call up Comp Cams. You need to find one that will match the RPM range of the TPI System and is compatiable with the computer. Back when I was in High School another student wanted to put a hi-po cam into his TPI camaro and picked a super lumpy one cause it looked "Fast". It made the idle horrible and the ECM did not care for the camshaft at all. Frankly it ran horrible in my opinion.

Doing a camshaft during motor overhauling I would recommend going to a double timing chain, replacing your valve stem seals, and springs for the new camshaft lifts.

After you find out what exactly you want don't be affraid to shop around. I use google and also froogle to find the best deals. Summit Racing and Jegs will both price match and beat competitors as long as they have a store front. I once made Summit Racing beat the price on a 3 piece aluminum Comp Cams cover which was around $100 difference and they did.

sofakingdom

iTrader: (1)

The Comp "500" grind is a good choice for an otherwise unmodified 305 TPI car like yours.

http://www.summitracing.com/parts/CCA-08-500-8/

You DO NOT want a cam that will create a "choppy" idle. That is the path right straight to a car that looks and sounds "great" but gets spanked by a Hyundai Sonata.

BGonski

What about when they say "lumpy" idel?
I had just purchased a comp cam performace valve train package.
This is what it says for it, but i'm waiting until spring to put all the new performance parts in.

But I have the cam, lifters,valve springs, timing set.
(Other parts yet to be installed: JEGS fuel pump; Chevy Throttle Bracket; JEGS fuel pump pushrod; Edelbrock performer 2011 intake manifold also edekbrock chrome valve cover and chrom fuel pump cover)
The car has no cat with flowmaster exhaust.



comp cam thumpr 279t H-107
The newest line of camshafts from Comp Cams is the "Thumpr". This line of retro-fit hydraulic roller and hydraulic flat tappet cams is designed for use in engines that originally used a flat tappet cam. It will give a significant increase in horsepower over an identical flat tappet grind. The "Thumpr" uses lobe profiles and grind characteristics that produce an early valve opening, long exhaust duration, and a generous overlap to give the engine a powerful and hard hitting exhaust note and a rough idle without sacrificing power output or streetability.

RPM Range: 2,000 to 5,800 rpm
Duration @ .050" lift: 227/241 (int/exh)
Valve lift: .479/.465 (int/exh)
Ideal for high performance street use, stock converter ok, best with
2000+ converter and gears, choppy, thumping idle.
Comp Cams 12-600-4

• Muscle car sound is back
• Hard hitting, lumpy idle
• Excellent throttle response and "streetability"
• Significant horsepower increase

Red 87 GTA

the cranes 2032 gets some bad rep but it is a great cam have it in my 350 and it woke that engine up like a freeken bat outa hell. its good with stock heads in the 350 but you should check your lift limit for the 305 because when it says limit it means the limt or you will have some major problems i recomend staying shy of it by about .020 or better. here are the specs for it

Brand: Crane Cams
Product Line: Crane CompuCam Camshafts
Part Type: Camshafts
Cam Style: Hydraulic roller tappet
Basic Operating RPM Range: 2,000-5,500
Intake Duration at 050 inch Lift: 214
Exhaust Duration at 050 inch Lift: 220
Duration at 050 inch Lift: 214 int./220 exh.
Advertised Intake Duration: 270
Advertised Exhaust Duration: 276
Advertised Duration: 270 int./276 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.452 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.465 in.
Valve Lift with Factory Rocker Arm Ratio: 0.452 int./0.465 exh. lift
Lobe Separation (degrees): 112
Intake Valve Lash: 0.000 in.
Exhaust Valve Lash: 0.000 in.
Computer Controlled Compatible: Yes
Grind Number: 2032
CARB EO Number: D-225-22

vetteoz

iTrader: (13)

Won't even sound that great because the low LSA (107 ) that the thumper series has to give the idle sound
you "want "; gives the computer a heart attack.
The valve overlap is so big the computer can not measure fueling correctly ;so thinking the engine is running lean it dumps in more fuel to the point where your eyes are watering from the raw fuel coming out the exhaust at idle and engine idles like a pig
Computer controlled engines like a LSA of 112 or higher

bcmag

ditto in my experience anything less than 114 is a crap shot.....wo a custom chip.doesnt need to sound nasty to be nasty!

vangogh4560

i have the CompuCam 2032 in my 305 and love it i have tried other cames over the years and i always go back to the 2032. its like a 450$ cam but worth it its got a nice sound and my baby not so stock 305 will run down a stock 350 all day long

vetteoz

iTrader: (13)

What about this similar spec cam ( w/ more lift ) for half the price?
http://www.summitracing.com/parts/HRS-180235-14/

even these two are over $100 cheaper

http://www.summitracing.com/parts/LUN-54779LUN/
http://www.summitracing.com/parts/LUN-50155/

vangogh4560

never used the 2 brands so cant say nothing good or bad..BUT at time's you do get what you pay for and a part like that is not one you would like to Grenade

sofakingdom

iTrader: (1)

Without trying to get into which is "best", any of the cams that have been suggested are appropriate, except for the Thumpr which will produce the perfect example of what I spoke of. You can't go too far wrong with any of them. They're all reputable brands.

However, ALL of them will give you a relatively smooth idle; which is one of the reasons they're appropriate in the first place.

vetteoz

iTrader: (13)

And many times you are paying extra for a " name" given that a lot of cam blanks in the USA only come from one source and are machined by different brands who put their names on them
Both Howards and Lunati are long established (1960's) companies with good racing history

camshafts are not something that generally grenades; they just wear the lobes off

Red 87 GTA

no no no stock lift limit on factory heads is 470/480 using these will make it go boom

Red 87 GTA

the cranes 2032 will make your car shake like crazy i have it and my antenna looks like its gonna have a heart attack with that much shake

vangogh4560

GENERALLY!!!!!! like i said cant say good or bad things about the brands

vetteoz

iTrader: (13)

So spend $50 on some new valve springs ( your old 150K ones are probably shot anyway ) and enjoy the extra lift

vetteoz

iTrader: (13)

Wasn't asking your "opinion" about the brand ; Most know they make quality stuff
Question was about using alternative cams with similar spec to the Crane for less $$$

vangogh4560

i did not give you my "opinion" I'm sure it was just the opposite of one