Ontario73

DucatiDon

Well the overall plan is to use 1.75 headers with the 2.5" exhaust.
The intake will be restrictive...I'd prefer not to go aftermarket ....so maybe I should stick to 195 heads. Anyone have flow numbers for stock intakes l76 vs z28 vs perfRPM? Be curious ....just how much I'd be giving up

DucatiDon

This....with a 383.....
http://forums.corvetteforum.com/c1-a...yno-video.html

Scott Marzahl

I don't follow. Joe isn't running a 383 and he is running large 220cc+ heads. A RPM and Z28 intake are pretty darn close in configuration. I ran a 383 back in 1980 when all these big heads and intakes were not common place. The heads were some old Brownfields 195ish ccs. The intake was Holley's copy of a Z28 intake which had to be extensively ported to mate up to the intake ports on the heads. If you are set on a factory intake, mate up the intake gasket reuquired for the 210 heads and see how much porting your intake requires.

cardo0

How bout a Zora Duntov single plane made by Holley and has the snowflake foundry logo? They have EGR fittings also. Not as powerful as is a bragg'n right item. They arent very expensive either - but used condition only.

http://www.chevelles.com/forums/atta...5&d=1368481053

Just a thought for sleeper vintage build sbc.

TCracingCA

First I would hope that all of the engineering and build specs have been decided on prior to buying expensive stuff, but it looks like great last minute advice is rolling in to get the project that final looking over for hoped success.

But then I would think that with as long as the 383 config has been around that someone would have figured it all out by now with a proven combination of power and reliability! But then there is always the latest and greatest coming out in the way of Cams and Heads!

For me and I tend to be old school, I looked for a proven combination and landed back when dinosaurs roamed the planet on mimicking the F-5000 builds of the 70's, with some Smokey Yunick and Bob Grumpy Jenkins and other tips thrown in!

Thus all of my engines that I have built have copied the porting, cams, head selections and such of those built, but with a few modern twists in the parts and techniques.

But even thou I am not fond of math, but it can be essential when absolutely necessary, there sure is a lot of good math going on here and I hope the slide rule approach turns out good results in the end, instead of just finding a successful role model! Maybe I am not going into the ranks of the great engine builders of the 20th Century by copying the work of Masters that came before, but they sure have held together and ran good!

65tripleblack

That's a .030 over 327 (331). Heads are ported 195s which are out to more than 200 cc.

DucatiDon

Ok, who has a flow bench and data?

A 327 using a Z28 intake (how many ccs?) and 220cc heads can run how many RPMs? (We see it is at least 7200 in the video above...)

How about a 383, using same intake, same heads...what RPM would it be limited to?

I guess I really need flow data for intakes...(ill check google right away)
If the Z28 or RPM intake can only flow, lets say 180cc, with 383 cubes, how much head will it prefer? Is 210 wasted? Is 195 better? Or canit handle 220? I need facts. not guesses.


Id like to see some hard numbers before I make some expensive decisions.

claysmoker

Here you go. Maybe this will help.

http://www.users.interport.net/s/r/s...ehdc.htm#Chevy

DucatiDon

Good Head data..still searching for intake data.
best Ive found is:

Perfomer RPM: 210 cfm
Victor Jr : 237 cfm
L76: ?
Z28/Lt1: ?

63mako

http://www.summitracing.com/parts/WND-7530/ Depending on hood clearance they have a + 3/4 (7532) or a +2" (7531) this fits stock C3 hood and 210 ports and gives up very little to nothing at off idle and gains a lot up top because you use the entire port. It is pretty much 0 restriction to the head port.

resdoggie

A lot of folks recommend the Eddie RPM Air Gap for its dual plane design, higher rpm range and more torque lower down. I used the Team G 7530. Am I losing that much low down torque to switch to an Air Gap? I'm somehow thinking not enough to justify the switch. And if not, then the guys who are concerned with hood clearance I would recommend you move to the SP Team G in your build as some of the experienced builders in this forum have suggested as an alternative to the Air Gap.

DucatiDon

Is the team G available with an oil fill tube hole?

Scott Marzahl

I think you are going to need a vintage type manifold for an oil fill tube. Here is a Weiand single plane with provision for fill tube.

http://www.ebay.com/itm/WEIAND-SBC-ALUM-SINGLE-PLANE-HIGH-RISE-INTAKE-MOD-7521-/251572171991?pt=Motors_Car_Truck_Parts_Accessories&hash=item3a92deb4d7&vxp=mtr
Otherwise if you stick with a dual plane intake, you will need to have a something like the RPM or LT1 intake ported to match the intakes of the heads you select.

Mr D.

Sweet

I also have a 512 large journal block with breather hole, picked it up about 3 months ago after looking for one for several years.

cardo0

Im surprised at all these large journal blocks as they had to be CE type "warranty replacements" for a '62-'63 as '62-'63 was the only years 512 casting # installed sb and was a small journal (327"). Several 512 casting numbered BB's for '68-'70 but not sbc.

maybe someone can elaborate here were the large journal sbc 512 blocks were installed?

JohnZ

THOUSANDS of them were installed, and they were still being cast well into the 70's; the 512 block never really had a production application - they were used exclusively for Service and warranty replacement, and were cast with and without the rear block vent hole, and were machined in both small and large journal versions.

The disastrous 5/50 powertrain warranty didn't start until 1967, and was gone by 1972, but the liability remained in the field into 1976.

65tripleblack

Chrysler had it for years. Maybe GM should have built high quality engines like Chrysler did.
I can hear all those NCRS guys muttering............."GM had a good reason for building it that way, so don't change it..............."

cardo0

Thx for explanation JohnZ.

Pop Chevy

I myself would limit a 383 to 6800 rpm due to piston wall speed, No I didn't do the math.