L83/L98 head swap
12-21-2012, 12:06 AM
#21
Team Owner
Pro Mechanic
What does ^that^ have to do w/what the OP is asking about?? FYI, bored TB's won't gain you squat on a stock or stocish engine, and especially on a 350 CID sized engine.
There IS a port match issue when using any non-Vortec intake on "Vortec" or any high port head (Vortec, LT1, LT4, Fastburn...). It CAN be worked around, but unless you get into welding and grinding, the workarounds (stacked gaskets, porting with THIN flanges) are less than ideal. Most people would see the mismatch and conclude that the parts won't work together. They CAN work together, but reliability and flow is somewhat compromised. Still, the Vortec head is cheap, great and I've had pretty good results bolting a CFI intake to Vortec heads -using "workarounds". NOTE that Vortec heads have an entirely different bolt pattern for the intake and using an older intake on Vortec heads requires plugging the Vortec head bolt holes, and drilling/tapping new intake manifold bolt holes, in the head.
There IS a port match issue when using any non-Vortec intake on "Vortec" or any high port head (Vortec, LT1, LT4, Fastburn...). It CAN be worked around, but unless you get into welding and grinding, the workarounds (stacked gaskets, porting with THIN flanges) are less than ideal. Most people would see the mismatch and conclude that the parts won't work together. They CAN work together, but reliability and flow is somewhat compromised. Still, the Vortec head is cheap, great and I've had pretty good results bolting a CFI intake to Vortec heads -using "workarounds". NOTE that Vortec heads have an entirely different bolt pattern for the intake and using an older intake on Vortec heads requires plugging the Vortec head bolt holes, and drilling/tapping new intake manifold bolt holes, in the head.
12-21-2012, 08:04 AM
#23
I had my throttle bodies bored by extreme efi I am really going slow on this rebuild/refresh but the throttle bodies seem to be done very nicely but I still need a few weeks to finish so I cant comment on how they work yet.Ive taken a few pics but I havent posted any yet.
12-21-2012, 08:06 AM
#24
What does ^that^ have to do w/what the OP is asking about?? FYI, bored TB's won't gain you squat on a stock or stocish engine, and especially on a 350 CID sized engine.
There IS a port match issue when using any non-Vortec intake on "Vortec" or any high port head (Vortec, LT1, LT4, Fastburn...). It CAN be worked around, but unless you get into welding and grinding, the workarounds (stacked gaskets, porting with THIN flanges) are less than ideal. Most people would see the mismatch and conclude that the parts won't work together. They CAN work together, but reliability and flow is somewhat compromised. Still, the Vortec head is cheap, great and I've had pretty good results bolting a CFI intake to Vortec heads -using "workarounds". NOTE that Vortec heads have an entirely different bolt pattern for the intake and using an older intake on Vortec heads requires plugging the Vortec head bolt holes, and drilling/tapping new intake manifold bolt holes, in the head.
There IS a port match issue when using any non-Vortec intake on "Vortec" or any high port head (Vortec, LT1, LT4, Fastburn...). It CAN be worked around, but unless you get into welding and grinding, the workarounds (stacked gaskets, porting with THIN flanges) are less than ideal. Most people would see the mismatch and conclude that the parts won't work together. They CAN work together, but reliability and flow is somewhat compromised. Still, the Vortec head is cheap, great and I've had pretty good results bolting a CFI intake to Vortec heads -using "workarounds". NOTE that Vortec heads have an entirely different bolt pattern for the intake and using an older intake on Vortec heads requires plugging the Vortec head bolt holes, and drilling/tapping new intake manifold bolt holes, in the head.
12-21-2012, 10:30 AM
#26
Team Owner
Pro Mechanic
No. What he meant was that Edelbrock makes intake manifolds for "Carb" applications and "TPI" applications in two versions; 1. for standard Chevy heads from '55 - '~mid '90s, and the other for "Vortec" heads, that has slightly raised ports.
Edelbrok doesn't make anything for the CFI platform; standard or "Vortec".
When you port your intake, port the WHOLE runner(s). From mouth to exit. You'll need to get a long grinding bit, and also a "drill bit extension" to reach all the way through. "Port matching" -which is about all most folks do, helps, but leaves a lot on the table. The more you grind out of that casting, the faster your car will go. It's THAT big of a restriction, in stock form.
Edelbrok doesn't make anything for the CFI platform; standard or "Vortec".
When you port your intake, port the WHOLE runner(s). From mouth to exit. You'll need to get a long grinding bit, and also a "drill bit extension" to reach all the way through. "Port matching" -which is about all most folks do, helps, but leaves a lot on the table. The more you grind out of that casting, the faster your car will go. It's THAT big of a restriction, in stock form.
12-21-2012, 10:47 PM
#27
No. What he meant was that Edelbrock makes intake manifolds for "Carb" applications and "TPI" applications in two versions; 1. for standard Chevy heads from '55 - '~mid '90s, and the other for "Vortec" heads, that has slightly raised ports.
Edelbrok doesn't make anything for the CFI platform; standard or "Vortec".
When you port your intake, port the WHOLE runner(s). From mouth to exit. You'll need to get a long grinding bit, and also a "drill bit extension" to reach all the way through. "Port matching" -which is about all most folks do, helps, but leaves a lot on the table. The more you grind out of that casting, the faster your car will go. It's THAT big of a restriction, in stock form.
Edelbrok doesn't make anything for the CFI platform; standard or "Vortec".
When you port your intake, port the WHOLE runner(s). From mouth to exit. You'll need to get a long grinding bit, and also a "drill bit extension" to reach all the way through. "Port matching" -which is about all most folks do, helps, but leaves a lot on the table. The more you grind out of that casting, the faster your car will go. It's THAT big of a restriction, in stock form.
to your first point - I knew that. My response just a gentle nudge to try to keep comments on topic.
to your second point - thanks, great input. I remember lots of porting details and pictures to with it back on crossfire injection vault, when i was considering this a few years back, but then life intervened, and now that site appears to have vanished. I will take your advice.
any opinions on ported cfi vs x-ram for stock moter and tb's, with 1.6 rr's and a hypertech chip? i've got an unused xram sitting in box also. another remnant from a few years back.
12-21-2012, 11:10 PM
#28
X-Ram will be an improvement. If you live in a really cold part of the country, it may run poorly while warming up..
12-22-2012, 06:29 PM
#29
Team Owner
Pro Mechanic
X-Ram will be an improvement over ann UNported, stock intake, for sure. I don't know anyone who's compared a stock, FULLY ported intake to the other options.
It is MY opinion (though I haven't tested back to back) that the FULLY ported stocker and an e-ram will perform about the same, except the Ported stocker will have better cold weather performance. The "plenum" in the X-ram is a joke, IMO. A bad joke.
The hypertech likely won't gain you a thing, and in fact I know several people who went slower with one. Spend your money and efforts elsewhere. Oops....you already have the Hypertech?
The hypertech likely won't gain you a thing, and in fact I know several people who went slower with one. Spend your money and efforts elsewhere. Oops....you already have the Hypertech?
12-23-2012, 03:45 PM
#31
Team Owner
Pro Mechanic
If you're going that route, it would be smarter to weld up the roof of the intake runners and grind them higher. Better transition, and you're not defeating the purpose of the "high port" fastburn heads. Make the (Crappy) intake better...don't "dumb down" the good heads.
12-23-2012, 09:00 PM
#32
Le Mans Master
If you're going that route, it would be smarter to weld up the roof of the intake runners and grind them higher. Better transition, and you're not defeating the purpose of the "high port" fastburn heads. Make the (Crappy) intake better...don't "dumb down" the good heads.
Very true!
