R1 vsR3 heads

[dixchief]

I am not finding the specs that make an R3 head.
were the head castings all the same?differences in valve size?
Can an head be modified to R3 specs?
TIA
Richard

[52-fan]

I am not an R-3 expert, but I think I can safely say that you cannot make an R-3 head out of an R-1. The pictures I have seen show an R-3 to have much taller ports and it takes a different intake manifold. The R-1 casting can be modified with R-3 size valves and ported to give excellent performance.
I'm sure someone more knowledgeable will fill in the missing info. Some pictures would be nice. Many of the experts may be cruising with their club today and not on the forum this morning.


1952 Champion Starlight, 1962 Daytona, both w/overdrive.Searcy,Arkansas
"I may be lazy, but I'm not shiftless."

[JDP]

quote:Originally posted by dixchief

I am not finding the specs that make an R3 head.
were the head castings all the same?differences in valve size?
Can an head be modified to R3 specs?
TIA
Richard

Different casting. You can install the R3 valves, but can't replicate the ports by using standard heads.

JDP/Maryland

[Alan]

The R3 heads are casting no 1555479. The valves are 1.910" apart on center same as a SBC. On R1 heads the valves are 1.780" apart. That is why I run .250" offset Procomp roller rockers on my R3's.

[Mike Van Veghten]

Richard -

Two part answer.

Part 1 -
Can a standard head be made into an R3 head.
Maybe close.
Not without a LOT of work and money.
You have to move the valves and do a lot of material removal, then welding, then reshaping new ports. You'd likely have 10 grand in them by the time you were done.

Part 2 -
Can a standard head be made to flow very well, better than most need. Very close to lightly modified R3 flow numbers (as I recall).
Yes, you can if you are, or you know someone good with a hand grinder, and have a good machine shop close by.
I am currently working on instructions to tell you how to do just that.
It'll be a couple more weeks before I'm done.
I thought I'd be done by now. Several things have slowed the process....including way more pages than I thought..!

Mike

[dixchief]

Thanks Mike. Your #2 answer is what I was looking for. I will await your advice when you have it together.Put me on your list or I will check back with you. I am rebuilding an R1 motor and would like to get the most punch for the buck. thanks again
Richard

[okc63avanti]

Michael Myers is going to do something very similar to the #2 option above on my R1 heads.

<div align="left">John</div id="left">

<div align="left">'63 Avanti, R1, Auto, AC, PW (unrestored)</div id="left">

[Mike Van Veghten]

I'm up to 17 pages and counting...

All from the experimenting I've been doing in the last year or so.
I was able to get 200CFM (stock is about 134cfm) with a 1.800" dia. intake valve. And the valve turned out to have a somewhat crummy shape (backside) by the time I was done. A better shaped valve should bring that 200cfm even higher.

This project has gotten much larger than I thought it would. Getting the details in there so they are somewhat understandable has beeen a challenge.

I'm worken on it...

Mike

P.S. - incase you havent seen these...something to look at -

http://public.fotki.com/-Mike-/

Double click to enlarge.

[tluz]

Interesting thread, guys. Mike and Richard, I am also planning to have some work done on my R1 heads and would be very excited to have some skinny to take to the machine shop. Mike, when you get done I'd love to get on the circulation list.

Thanks,

Tom