The high cost of building iron...
- Thread starter Tom Kochtanek
- Start date
I understand the "challenge" aspect of any build. The challenge of doing it my way, the challenge of having my end result. I'd better understand the challenge. My chosen challenge is old school style with new school tech.I agree with your comments on "old iron". That's why I went in this direction. I understand some builder's fondness for aluminum, but wanted to stay old school.
I think it's a challenge to resurrect these 50 year old parts
TomK
It isn't wrong, it isn't right, it's just what I want
The sad thing is that one of the cam companies I talked too wanted the flow numbers from the heads to help him pick a grind and that would mean more money would have to be thrown at them.
You can guaranteed I will and Tom is going to have a big smile on his face watching and listening them babies scream down the track.
And if someone shows up without a ride they could get a chance at them also.
Skip FIx
Well Known Member
Flow numbers actually are important at least exhaust/intake ratios to base duration splits for the cam. Why my Edelbrock head 409 has a single pattern cam, and why a "reverse split"- more exhaust duration worked better on one of my Pontiac heads that had > 85% exhaust flow/intake flow.
Why is wanting the flow numbers a sad thing? They want to be able to specify the most appropriate specs for his individual engine. Anything else would just be an assumption and result in a best guess grind.
That was just having to spend more money on them
Anyone know what the "stock" flow numbers are for a set of unmodified 583s?
TomK
TomK
Figure the intake for 300 @.500, 310 @ .600, and 315 @ .700. I don't know what valve shape you went with or valve angles, but those numbers should be more than good enough for figuring a cam. The exhaust would be 225 @ .500, 235 @ .600, and 245 @ .700. That is with a 1.75 valve.
Dan:
Thanks for the quick reply. The intakes are now 2.25" and the exhaust is 1.80". Not sure of valve shape/angles, will ask at the machine shop.
These 583 heads and the new cam are for the next engine build, a 460" stroker. James is hoping to get it together in a month for Byron and stuff it in BA409. We'd also like to get the Pontiac rear end setup this summer.
For now we've got a stock stroke truck block with used pistons and R&R'd con rods along with modified 690s. James put a posi together with better axles and different gears to replace the welded up open rear we used last year.
Getting ready to depart in the early AM for Bowling Green with the BA409 in tow .
Cheers!
TomK
Thanks for the quick reply. The intakes are now 2.25" and the exhaust is 1.80". Not sure of valve shape/angles, will ask at the machine shop.
These 583 heads and the new cam are for the next engine build, a 460" stroker. James is hoping to get it together in a month for Byron and stuff it in BA409. We'd also like to get the Pontiac rear end setup this summer.
For now we've got a stock stroke truck block with used pistons and R&R'd con rods along with modified 690s. James put a posi together with better axles and different gears to replace the welded up open rear we used last year
.Getting ready to depart in the early AM for Bowling Green with the BA409 in tow
.Cheers!
TomK
I only had one cam company ask.
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61 Bubble
Well Known Member
DOUBT these are STOCK flow numbers? reason is:
"330 cfm at .700 with a 690 head is very difficult to do. I think I am at 312 or so at .700 and 318 at .800 with a 2.275 intake valve and a LOT of porting. The pinch area is as thin as I can get it and a lot of bowl work. I have a 3/8 valve stem so that hurts a little. Unless you are stuck on using the iron heads (like me), you would be time and money ahead to get the edelbrock or BWR heads with one of the cnc programs out there to get 330 cfm. 330 out of a 690 would likely require brazing, welding, or epoxy to fill in certain areas and patch the holes in the port you are bound to make."
YOU posted that on Feb 24th in my thread about stroked 409 RPM limitations! So now your saying that a stock 583 will flow 315 @.700, and a 690 with a 2.275 312? LESS than a the stock 583????? So you have a set of 690's PORTED with a 2.275 valve and they flow less then a set of 583's?
Those are ported numbers. I ported the heads he has now the same as mine. I gave him those numbers based on what mine flowed so he would have a basis to go off of. I don't know how the heads were finished so those are round numbers to give him a good idea. Does that make sense to YOU now?
