Valve differences

Zeke...PA

Zeke...PA

Well-known member
What is the difference between 49-50 and 51-53 intake & exhaust valves. I know the 49- 50 block usually has hardened seats. Thanks Zeke
 
tI'm doing research on this righ now. I talked to Mac VanPelt yesterday about buying various parts to compare the two. I did get this much from Mac (the valve is longer on the '51-'53), spring (shorter on the '51-'53), spring retainer (Part 1BA-6517) (cupped for the sleeve) and a sleeve? (part #1BA-6517) are all different than the '49 and '50 valve assemblies. I also talked to Mac's Auto Parts about this as they don't list the sleeve in their catalog. I e-mailed them the attached pic and they are going to research it. Supposedly the change allowed the valves to rotate on the '51 thru '53 engines. It may take a couple of weeks but I will develop a post when I have the full info. Basically only the valve guides and horseshoe clips are the same.

Jim

Here's a pic from Mac VanPelt's website:

391495718.jpg
 
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blown49 said:
tI'm doing research on this righ now. I talked to Mac VanPelt yesterday about buying various parts to compare the two. I did get this much from Mac (the valve is longer on the '51-'53), spring (shorter on the '51-'53), spring retainer (cupped for the sleeve) and a sleeve? (part #1BA-6517) are all different than the '49 and '50 valve assemblies. I also talked to Mac's Auto Parts about this as they don't list the sleeve in their catalog. I e-mailed them the attached pic and they are going to research it. Supposedly the change allowed the valves to rotate on the '51 thru '53 engines. It may take a couple of weeks but I will develop a post when I have the full info. Basically only the valve guides and horseshoe clips are the same.

Jim

Here's a pic from Mac VanPelt's website:

391495718.jpg
Click to expand...



The info in the picture is 100% correct. call c&g ford parts 1-760-740-2400 I think they sell the # 6514 & #6517 as a pair. I have rebuilt a few 51 engines and they all had the rotating valve assy. some say it started in 52 but they actually started in 51.
 
Many of the late 51 to end flathead V8 valves were replaced with the earlier type due to lack of availability back in the 60s. The "rotator" type valve stuff was hard to find and still is to a certain extent (parts are available but you have to really dig to find some of them). Everthing but the guide and the horse shoe clip is different in the basic valve & spring assembly.

Kerby
 
My experience differs slightly. To my recollection, the valves were the same length, but the keeper position is higher which makes room for the additional cone, the primary component which makes the rotation possible. Having experience with both systems, my preference is for the later technology, hard seats or not. It gives you a little more room to work on adjusting, either with adjustables or stem grinding.
 
Thanks, this is great information. I still think the change came sometime in 51, but I could be wrong. Anyway, what you do with the info is up to you.
 
Let me skin my ignorance here. Don't all early Fords have hardened valve seats? Isn't that why unleaded gas doesn't matter in the flatheads? Inquiring minds want to know.
 
Seats are cheap, got them a few times at NAPA. They have no valve angle at all, have to eat up some coarse stone to whittle out a valve surface.
 
Ol' Ron, I am sure you are correct. All the literature suggests that all the 51s had rotators but both of my early 51 Mercurys have old style. I don't know when the change came but it was some where closer to mid 51 production. The valves are a different length (near .030" or .040" I can't remember) and the keeper grooves are in a different location.
 
I received my order from Mac VanPelt and proceeded to make some CAD drawings of the various assemblies and components with part numbers.

The critical dimension, as I see it, is the dimension in the block from the center of the valve seat to the top of the horse shoe clip slot in the guide. If the block has been decked or major grinding of the valves or seats has occurred, the valve in theory becomes longer from the lower spring retainer to the guide spring seating surface and lengthens installed spring height and owers seat pressure.

Comments appreciated.

I'm also working on a drawing for using C**** Manley Street Flow Stainless valves in the Ford flattie with stock springs or ISKY 185G springs.

More later

Jim
 

Attachments

Here's another drawing I made of valve choices including the Manley SS Street flow valves (according to Joe Abbin flow bench testing yields up to a 4% gain in flow using these velves) and a Buick V-6 valve they make for severe duty. I have listed the individual valve weights for the Manley valves but have not measured the weights of the Ford valves.

Jim
 

Attachments

Thanks, I printed this info for future use. FYI the amt of material removed fron seat grinding will have little or know affect on spring pressure. Stainsles steal valves are bad for cast guides unless chrome plated. Most aftermarket guides are too oose for the valve. Knurling and fitting the valves to .0005-.001" stem clearance prevents oil contamination of the combustion chamber.
A thin coating of RTV on the guide is all that's necessary cor intake guide seal. Harden seats on the intake valves is un-necessary.
This is most of the valve info I have.
 
My experience. I needed 3 ea .060 shims to get the valve spring installed heigth right. The Isky springs are wound backward from Ford springs and it is hard to get the pry bar in them. The Chvy valves were so long,almost all the adjustment had to be out of the lifters. The keeper/retainer set made them so close to the end of the valve plus the adjuster all the way down made it impossible to adjust the valves. I put in Ford valves and springs.
 
Lawson Cox said:
Let me skin my ignorance here. Don't all early Fords have hardened valve seats? Isn't that why unleaded gas doesn't matter in the flatheads? Inquiring minds want to know.
Click to expand...

I think that somewhere around the last year for the flathead the seats were ground right into the block. Dont remember if it was just the intake side or both intake and exhaust.
 
Thanks Jim for taking the time to do the drawings and sharing them with us, much appreciated and good information to have.

Vergil
 
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