Who sells larger size intake valves?
 

Re: Who sells larger size intake valves?
 

Larger valves are probably not going to be readily available from the standard suppliers of Model "A" parts.
You can source them from places like Dennis Piranio https://www.modelaparts.net/
I am sure there are others, possibly Red's Headers etc.
There are pretty well known conversions, one that comes to mind is a Chevy Bigblock valve, this can be researched in automotive catalogs.
Adding larger valves is not just a bolt in operation, it requires other work and more than likely other components.

Best to keep asking, Jim Brierley is a great source of information.

Good luck, John

Re: Who sells larger size intake valves?
 

I have a box of US made valves that are of the exact same dimensions as original type Model A/B valves except that they are 1/8 inch oversize. I had never seen or heard of oversize valves from that era and wonder if these were intended for the Model A or were for some other engine and just happen to fit the A/B block?

This came from some parts that came from the estate of a guy that was involved with racing in the 30's and 40's. Somebody beat me to the really good stuff but I did get some oddities such as a set of rebabbitted rods that were modified to have extended oil scoops in the caps (!?).

Re: Who sells larger size intake valves?
 

If you are speaking of valve head size, then one of the easiest suppliers would be Rich Fallucia at Antique Engine Rebuilders. He offers them in a kit.

Re: Who sells larger size intake valves?
 

Berts

https://modelastore.com/index.php?ro...&category_id=0

Re: Who sells larger size intake valves?
 

Re: Who sells larger size intake valves?
 

ursus, those valves could be for 1941 Ford 6 cyl. Later Ford 6's had 11/32" stems, '41 was the only one with 5/16" stems and would fit right into the Model A, with minor enlarging of the ports.

Re: Who sells larger size intake valves?
 

Thanks, Jim. I was hoping that somebody with extensive knowledge of this area would respond. One would think that use of such oversize valves would have been more widespread, especially with engines needing inserts because of worn out and overly recessed valve seats.

Re: Who sells larger size intake valves?
 

I've used them, sort of. They are 0.2" over size but I didn't like the idea of removing good solid, original cast iron from right where the Model A block is already prone to cracking. I didn't want to put hardened seats in so my compromise was to reduce the valves to 0.1" oversize. That still meant a new seat higher in the block but not much cast iron gone. Even with that, it is my best breathing Model A engine.
If I were to build another engine, I think I'd put the larger valves in with seats.

Re: Who sells larger size intake valves?
 

Many years ago before titanium valves we used John Deere valves made by SBI, for model B hot rod applications. The intake heads were a bit over 1.8 and the ex. were a bit over 1.7.
The stems were 5/16 and chromed. The stems were WAY too long so we had to cut them and regroove them. We usually had to do that anyway with any valve used because of cam design. They lasted many moons in race applications.
I did a quick search and couldn't find that number but someone must still make them because many of the engines they went in are still around.
Find a parts house with a friendly counter person that will let you look through his progressive size charts. You will need new springs, retainers and split locks also. All still available. Hot rod and racing equipment catalogs are good sources of info and parts also.
Putting in big valves won't help much unless you do some porting and install a modified cam also.
In another thread on here, cost of modifications was discussed.