View Poll Results: which heads should i upgrade with?
vortec heads 64cc
34
69.39%
l98 corvette aluminum heads 58cc
15
30.61%
Voters: 49. You may not vote on this poll
poll about which heads...again!
Thread Starter
Burning Brakes
Joined: Sep 2005
Posts: 832
Likes: 0
From: Sarasota Florida
i dont know what head you have. 882 casting would be my guess, any way they dont flow as well as a vortec but the port is smaller and low lift numbers are pretty close only a few cfm more for the vortec, but with a bigger port. only at the top of your cam will you see much flow increase and its not their long, mainly in the .150 to .300 lift area. i am not trying to deter you from what you want to do, just help you get the most out of your time, and money.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
compression first & foremost
Just my observation & 2 cents worth of broad generalization:
Seems Andy has large chambers, dished pistons, low compression and big cam.
Seems to me Andy's primary need is more compression ... and seems he ain't likely to change pistons ... seems his primary need is smaller chambers. Better flow is secondary or tertiary ... seems about any head will flow enough for Andy's street use. But not any head will make compression ... 882 and their ilk sure won't.
Seems Andy has large chambers, dished pistons, low compression and big cam.
Seems to me Andy's primary need is more compression ... and seems he ain't likely to change pistons ... seems his primary need is smaller chambers. Better flow is secondary or tertiary ... seems about any head will flow enough for Andy's street use. But not any head will make compression ... 882 and their ilk sure won't.
Thread Starter
Burning Brakes
Joined: Sep 2005
Posts: 832
Likes: 0
From: Sarasota Florida
Just my observation & 2 cents worth of broad generalization:
Seems Andy has large chambers, dished pistons, low compression and big cam.
Seems to me Andy's primary need is more compression ... and seems he ain't likely to change pistons ... seems his primary need is smaller chambers. Better flow is secondary or tertiary ... seems about any head will flow enough for Andy's street use. But not any head will make compression ... 882 and their ilk sure won't.
Seems Andy has large chambers, dished pistons, low compression and big cam.
Seems to me Andy's primary need is more compression ... and seems he ain't likely to change pistons ... seems his primary need is smaller chambers. Better flow is secondary or tertiary ... seems about any head will flow enough for Andy's street use. But not any head will make compression ... 882 and their ilk sure won't.
Safety Car
Joined: Oct 2005
Posts: 3,570
Likes: 1
From: Algonac Michigan
I must say....I have never heard or had bad advice from Jackson!!!
A engine GURU in my book. Thank you for the advice in the past.
Check into the heads HE has for sale!!!
If they are not for you he will tell you so!!
I try to get all my eng advise from him.
A engine GURU in my book. Thank you for the advice in the past.
Check into the heads HE has for sale!!!
If they are not for you he will tell you so!!
I try to get all my eng advise from him.
Race Director
Joined: Oct 2000
Posts: 15,014
Likes: 79
From: central FL, near the beach.
andy
i don't know why u don't want a smaller cam?
cheap fix.
.
but the 50cc EngineQuest $475/pr bare would get u to 10:1 way more power
i don't know why u don't want a smaller cam?
cheap fix.
.
but the 50cc EngineQuest $475/pr bare would get u to 10:1 way more power
Last edited by Matt Gruber; Nov 29, 2007 at 04:52 PM.
Thread Starter
Burning Brakes
Joined: Sep 2005
Posts: 832
Likes: 0
From: Sarasota Florida
i had a smaller cam and upgraded to this one. it has a much better powerband up top. the problem i have is the low compression. i have been emailing jackson, and he has been helping me extensively. he said that with this cam, i could probably go with either head and expect 340-355 hp, which is comparable to a zz4 crate.
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
The 58 cc aluminum head is what you need for your L/48' if you
end up with 10.0 comp. that would be fine with an aluminum head,
the problem comes with your future plans, that L/98 head has small
runners, valves, ment to work on a 350 with a fuel injection system that was all done in providing air at 4500 rpm. you put them on a 383
they will strangle it for air. your going to end up with both to small
of runners and tiny ( for a 383 size engine ) 1.94/1.50 valves.
Think about this just on the valves in your future plan for a stroker 383,
chevy came out with the 1.94/1.50 valves on the power pack 283s
you will end up with the same valve size in an engine with 100 more
cubic inches.
end up with 10.0 comp. that would be fine with an aluminum head,
the problem comes with your future plans, that L/98 head has small
runners, valves, ment to work on a 350 with a fuel injection system that was all done in providing air at 4500 rpm. you put them on a 383
they will strangle it for air. your going to end up with both to small
of runners and tiny ( for a 383 size engine ) 1.94/1.50 valves.
Think about this just on the valves in your future plan for a stroker 383,
chevy came out with the 1.94/1.50 valves on the power pack 283s
you will end up with the same valve size in an engine with 100 more
cubic inches.
Last edited by Little Mouse; Nov 29, 2007 at 05:16 PM.
Thread Starter
Burning Brakes
Joined: Sep 2005
Posts: 832
Likes: 0
From: Sarasota Florida
The 58 cc aluminum head is what you need for your L/48' if you
end up with 10.0 comp. that would be fine with an aluminum head,
the problem comes with your future plans, that L/98 head has small
runners, valves, ment to work on a 350 with a fuel injection system that was all done in providing air at 4500 rpm. you put them on a 383
they will strangle it for air. your going to end up with both to small
of runners and tiny ( for a 383 size engine ) 1.94/1.50 valves.
Think about this just on the valves in your future plan for a stroker 383,
chevy came out with the 1.94/1.50 valves on the power pack 283s
you will end up with the same valve size in an engine with 100 more
cubic inches.
end up with 10.0 comp. that would be fine with an aluminum head,
the problem comes with your future plans, that L/98 head has small
runners, valves, ment to work on a 350 with a fuel injection system that was all done in providing air at 4500 rpm. you put them on a 383
they will strangle it for air. your going to end up with both to small
of runners and tiny ( for a 383 size engine ) 1.94/1.50 valves.
Think about this just on the valves in your future plan for a stroker 383,
chevy came out with the 1.94/1.50 valves on the power pack 283s
you will end up with the same valve size in an engine with 100 more
cubic inches.
i can have a bit higher compression with aluminum heads...what compression should I aim for for street/strip? i'd have around 9.5:1 w/ vortecs and 9.75-10:1 with aluminum.
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Thread Starter
Burning Brakes
Joined: Sep 2005
Posts: 832
Likes: 0
From: Sarasota Florida
Racer
Joined: Oct 2006
Posts: 435
Likes: 18
From: Florida
Yes they can be made to, but i dont believe its just a spring swap, i believe they have to be machined...... i am not positive though. no i dont, i do think they are a good head. I happen to have trick flow twisted wedge heads on a 383 with the biggest comp extreme 4x4 cam, weind stealth intake and somewhere in the 10.0:1 compression range.
Thread Starter
Burning Brakes
Joined: Sep 2005
Posts: 832
Likes: 0
From: Sarasota Florida
Yes they can be made to, but i dont believe its just a spring swap, i believe they have to be machined...... i am not positive though. no i dont, i do think they are a good head. I happen to have trick flow twisted wedge heads on a 383 with the biggest comp extreme 4x4 cam, weind stealth intake and somewhere in the 10.0:1 compression range.
Thread Starter
Burning Brakes
Joined: Sep 2005
Posts: 832
Likes: 0
From: Sarasota Florida
okay so i found a nice pair of vortec heads for sale. i have a few questions...
1. can i use the stock EXHAUST manifolds on the vortec heads?
2. will all my accessories bolt right up to the heads?
1. can i use the stock EXHAUST manifolds on the vortec heads?
2. will all my accessories bolt right up to the heads?
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
Actually, no I don't. The motor I have is an aggressively built 350 of unknown year and origin. It's a motor I rebuilt about ten years ago when the block in my Vette cracked. The engine came out of one of my other two '77 Vettes when I replaced them with crate motors.
I do know it wasn't a Corvette specific block but it was all I had and didn't know squat about motors. It was the first engine I ever built and it still runs great.
I'd guess around 300 HP.
I have considered the Vortec swap but this 350 is on borrowed time anyway. I have a roller 400 built and ready to go with LT1 heads and an LT1 fuel injection manifold.
If I didn't have the 400, I would do a Vortec swap for sure.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
Also ... all "legal" late model & charger class circle track cars in my region required to run 1.94/1.5 in UNported production 75-76cc heads milled ... most milled to rule minimum 70cc ... Most run about 375fwhp ... but I've seen several legal ones flirt w/ 400FWHP on dyno (110 race gas) with A TWO barrel ... well over 400 w/ 4 barrel ... that's unported 1.94/1.5 production heads ... just pickin'. BTW ... most are 355-360ci ... all are 75-76cc production heads milled to 70cc minimum /rule ... flattops /rule ... .480" max Vlift /rule. We see cheating every week ... but we don't see folks doing it by going to larger valves. Keep in mind those are not street motors ... they spend about an hour /weekend at around 6.5-7K ... w/ 1.94/1.5 ... just pickin'
Le Mans Master
Joined: Apr 2006
Posts: 5,403
Likes: 95
Just pickin' ... but what size valves came in sbc400 (17 more inches than planned 383) ??????? I've got a coupla pair of OE sbc400 heads ... both sets have 1.94/1.5 ... just pickin' ... I know your avg OE sbc400 ran about as quick as a bassackwards drut ... just pickin'
Also ... all "legal" late model & charger class circle track cars in my region required to run 1.94/1.5 in UNported production 75-76cc heads milled ... most milled to rule minimum 70cc ... Most run about 375fwhp ... but I've seen several legal ones flirt w/ 400FWHP on dyno (110 race gas) with A TWO barrel ... well over 400 w/ 4 barrel ... that's unported 1.94/1.5 production heads ... just pickin'. BTW ... most are 355-360ci ... all are 75-76cc production heads milled to 70cc minimum /rule ... flattops /rule ... .480" max Vlift /rule. We see cheating every week ... but we don't see folks doing it by going to larger valves. Keep in mind those are not street motors ... they spend about an hour /weekend at around 6.5-7K ... w/ 1.94/1.5 ... just pickin'
Also ... all "legal" late model & charger class circle track cars in my region required to run 1.94/1.5 in UNported production 75-76cc heads milled ... most milled to rule minimum 70cc ... Most run about 375fwhp ... but I've seen several legal ones flirt w/ 400FWHP on dyno (110 race gas) with A TWO barrel ... well over 400 w/ 4 barrel ... that's unported 1.94/1.5 production heads ... just pickin'. BTW ... most are 355-360ci ... all are 75-76cc production heads milled to 70cc minimum /rule ... flattops /rule ... .480" max Vlift /rule. We see cheating every week ... but we don't see folks doing it by going to larger valves. Keep in mind those are not street motors ... they spend about an hour /weekend at around 6.5-7K ... w/ 1.94/1.5 ... just pickin'
Chevy did it for yrs, You could easly make 400/450 hp or way more
out of any 350 with any kind of head you want to use, just
spin it fast enough, but what does that prove most people want
a little low rpm hydraulic cam with torque down low today, they don't
even want to be bothered with adjusting solid cams anymore.
400s were just a real low rpm torque engine to get that heavy 70 monty carlo
rolling, chevy did not bother to make a performance engine out of it.
Guy I knew in the 70s ran a 292 factory heads ran low 10.0s
with it but it was spinning to the moon lol. His car was a
65 coupe, he had the E-mod production record for a short time,
had 5.57 rear, doug nash 5 speed, he had those monster 202/160
valves,
Believe racing head service in memphis did the portingwork, this was when I lived in Little Rock just south of Big Rock.
Last edited by Little Mouse; Dec 2, 2007 at 06:37 AM.