81 engine freshen need estimate please!
Thread Starter
Instructor
Joined: Feb 2005
Posts: 136
Likes: 0
81 engine freshen need estimate please!
Alright all you pro covettest's have an 81 vette stock motor 8.2.1 compresson, going to put:
edelbrock performer eps
holley street avenger 670 cfm carb
mallory 85 series hei distributor
no egr no computer
comp cam specs bellow
Intake Duration at 050 inch Lift: 224
Exhaust Duration at 050 inch Lift: 224
Duration at 050 inch Lift: 224 int./224 exh.
Advertised Intake Duration: 270
Advertised Exhaust Duration: 270
Advertised Duration: 270 int./270 exh.
hooker super comp side pipes with no mufflers(straight pipe)
can some one tell me an estimated hp at the flywheel?
I have a buddy with 1988 iroc z enginge stock only mods are cat back system, hp chip and kn air filter who wants to race do I have a Chance
Please help
edelbrock performer eps
holley street avenger 670 cfm carb
mallory 85 series hei distributor
no egr no computer
comp cam specs bellow
Intake Duration at 050 inch Lift: 224
Exhaust Duration at 050 inch Lift: 224
Duration at 050 inch Lift: 224 int./224 exh.
Advertised Intake Duration: 270
Advertised Exhaust Duration: 270
Advertised Duration: 270 int./270 exh.
hooker super comp side pipes with no mufflers(straight pipe)
can some one tell me an estimated hp at the flywheel?
I have a buddy with 1988 iroc z enginge stock only mods are cat back system, hp chip and kn air filter who wants to race do I have a Chance
Please help
Race Director
Joined: Jul 2004
Posts: 12,706
Likes: 329
From: Scottsdale Arizona
Originally Posted by bickel
for a low price what heads would you recomend?
Drifting
Joined: Aug 2004
Posts: 1,883
Likes: 124
From: Lubbock TX
You could pick a better, more modern cam. That one doesn't come alive until about 3K and is pretty much a dog below that. Try the voodoo 231/239 - it'll suit your needs better. Also look at different heads, those are pretty sorry as far as power makers go.
Safety Car
Joined: Dec 2004
Posts: 4,071
Likes: 0
From: San Diego CA
Can probably find a set of rebuilt heads with better flow for $400.
A pair of vortec heads + intake manifold will run ya about $700, that'd eat him alive.
His cam's operating range is probably 2300 - 5500. The L82's cam is 222/222 but I don't know the lift on either so I can only guess.
Junking your emissions system and going with electric fans will give you a chance, too.
A pair of vortec heads + intake manifold will run ya about $700, that'd eat him alive.
His cam's operating range is probably 2300 - 5500. The L82's cam is 222/222 but I don't know the lift on either so I can only guess.
Junking your emissions system and going with electric fans will give you a chance, too.
Melting Slicks
Joined: Jan 2005
Posts: 3,028
Likes: 0
From: Madison Ms
Espcially the GM vortec heads..........Often ignored, but mostly copied. These are very good street heads!! Make sure you free up your exhaust in order to gain the full benefits of your mods!!
Melting Slicks
Joined: Jan 2004
Posts: 2,672
Likes: 1
From: New Cumberland PA
Since you are planning on replacing the intake, the Vortec heads make a lot of sence. The only downside if you choose the Vortec heads is that the cam will be limited to .480" or less unless they are modified. If your goal is a stout street machine (330-400hp), I think the cam limitation will not be a factor since there are cams out that should work fine. Some performance shops will sell you everything you need to make the swap/upgrade; including gasket set, bolts, rockers, valve covers, etc.
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Melting Slicks
Joined: Jan 2005
Posts: 3,028
Likes: 0
From: Madison Ms
Originally Posted by mandm1200
Since you are planning on replacing the intake, the Vortec heads make a lot of sence. The only downside if you choose the Vortec heads is that the cam will be limited to .480" or less unless they are modified. If your goal is a stout street machine (330-400hp), I think the cam limitation will not be a factor since there are cams out that should work fine. .
Melting Slicks
Joined: Aug 2003
Posts: 3,416
Likes: 291
From: dayton oh
you're only halfway there
OK -- you've solved the intake/carb problem (inhale), and the exhaust problem (exhale)..................
BUT heads are where the power is at. I started out trying to upgrade my stock heads -- most shops wouldn't touch them due to the thin castings cracking when port/polising. Then went on head info search for 18 months reading every article i could find. For heads on a budget, you'd be hard-pressed to beat the Vortecs or the World S/R Torquers. you'd need a different intake for the Vortecs, while the intake you're planning on using would work with the S/R Torquers.
I ended up with the alum AFR 180's so i could squeeze more CR on pump gas, but those 2 above were VERY close flow contenders in cast iron.
Also, what rearend you running?? going from 3.08 to 3.73/3.90 would make your semi-stock motor feel MUCH more powerful....and cheaper than heads
BUT heads are where the power is at. I started out trying to upgrade my stock heads -- most shops wouldn't touch them due to the thin castings cracking when port/polising. Then went on head info search for 18 months reading every article i could find. For heads on a budget, you'd be hard-pressed to beat the Vortecs or the World S/R Torquers. you'd need a different intake for the Vortecs, while the intake you're planning on using would work with the S/R Torquers.
I ended up with the alum AFR 180's so i could squeeze more CR on pump gas, but those 2 above were VERY close flow contenders in cast iron.
Also, what rearend you running?? going from 3.08 to 3.73/3.90 would make your semi-stock motor feel MUCH more powerful....and cheaper than heads
&amp;quot;Rodstoration &am p;quot; In Progres
Joined: Jun 2004
Posts: 1,397
Likes: 1
From: Frisco TX
I did some comparison analysis after I had my Edelbrock RPMs ported and polished... here is the link with graphs and data for several heads.
http://forums.corvetteforum.com/show....php?t=1326866
http://forums.corvetteforum.com/show....php?t=1326866