I have not been able to find this information. I would like to know the diameter specification, and also the +/- tolerance, or else the min and max diameter specification, if that is how it is given. As I understand it, this specification is the same for regular wedge FEs and cammers. Thanks in advance - Jay


Jay Brown
1968 Shelby GT 500 Convertible, 492" 667 HP FE
1969 R code Mach 1, 490" supercharged FE, 9.35 @ 151.20, 2007 Drag Week Runner Up, Power Adder Big Block
2005 Ford GT, 2006 Drag Week Winner, 12.0 Daily Driver
1969 Ford Galaxie XL, 460 (Ho Hum....)
1964 Ford Galaxie 500, 510" SOHC

0.839 - 0.840



68 Mustang F/B
67 Fairlane GT

scan from '66 manual (temporary picture)

edited- add picture

The 67 Factory Manual

Rocker Arm Shaft O.D. 0.839 - 0.840
Rocker Arm To Shaft Clearance 0.0030 - 0.0055 Wear Limit -0.0060
Rocker Arm Bore Diameter 0.843 - 0.844




68 Mustang F/B
67 Fairlane GT

check oout the size from Bills' post on the '58!
Apparently this was changed allot.

I think I read that you were using a heavy duty shafts on your motor.
Where did you get them? I'll need some for my 428 at some point in the next year.
My old TP that I raced had gun drilled shafts that I got from FPP. I'm not sure who made them but I would like to find another set.

Mike G

.

Jay Brown
1968 Shelby GT 500 Convertible, 492" 667 HP FE
1969 R code Mach 1, 490" supercharged FE, 9.35 @ 151.20, 2007 Drag Week Runner Up, Power Adder Big Block
2005 Ford GT, 2006 Drag Week Winner, 12.0 Daily Driver
1969 Ford Galaxie XL, 460 (Ho Hum....)
1964 Ford Galaxie 500, 510" SOHC

n/m

Courtesy of the '67-'68 Ford Shop Manual The Old Car Manual Project

352 specs are on the far right. Courtesy of The Old Car Manual Project. Previous post was '67-'68 T-bird

My 68 manual says the same .839-.840 shaft dia with a rocker to shaft clearence of .003-.0055 with a wear limit of .0060. John

It is rather interesting that there is a little variation in the specs, but what is clear is that the clearance is a lot more than .001", which is what my T&D rockers measured. I'll make sure that T&D gets this information - Jay

Jay Brown
1968 Shelby GT 500 Convertible, 492" 667 HP FE
1969 R code Mach 1, 490" supercharged FE, 9.35 @ 151.20, 2007 Drag Week Runner Up, Power Adder Big Block
2005 Ford GT, 2006 Drag Week Winner, 12.0 Daily Driver
1969 Ford Galaxie XL, 460 (Ho Hum....)
1964 Ford Galaxie 500, 510" SOHC

The SAE paper on GT-40 engine development has the rocker-to-shaft clearence at .0015-.003.

According to the print on Dave's Supermotors file site.

http://www.supermotors.net/vehicles/registry/media/158543_1





1912 Model T Ford touring Salmon (ugh!)
1913 Model T Ford Touring original Black paint
1915 Model T Ford Roadster Black
1915 Model T Ford touring Black of course!
1967 Cougar GT 390 Cardinal Red / Black
1968 Cougar GTE 427 Augusta Green / Saddle
http://www.supermotors.net/vehicles/registry/15029/50071-2

I had my rockers honed to about .001-.0015 clearance. Guess that's why I do not need restrictors with my EBOK heads and got away with .090 restrictor in my CJ heads.
My thought is a small shaft needs tighter clearance to keep oil pressure up on the bearing surface.

I wonder if the specs really mean anything.

They were created with grocery getting in mind, not performance.
So how did it matter how loose or tight they were? It was assumed that there would always be sufficient oil, so if you used a rocker with a two inch bore on a one inch shaft, it probably would have worked ok. Then came the y-block which was the poster child of rocker arm/shaft wear, thanks to the crummy oil of the day and crummy oiling system.

If you are doing a high revolution performance engine of any configuration, seems like a set of proper clearances for that would need to be developed from scratch. At high rpm with high valve spring load, I bet a rocker with a two inch bore would bounce pretty good on a one inch shaft. The idea then would seem to me to get the bore of the rocker close enough to the shaft so that it would always be in contact with the oil film.

I have seen some great video of a valve spring in action at high speeds. I wonder what a rocker/push rod etc would look like in high speed action.

...my 1965 service specs for cars & trucks, rocker arm to rocker shaft clearance:
__________________________________________________________

*Cars*, 352, 390, 427 & 430/ 0.003-0.005 wear limit 0.006
__________________________________________________________

*Trucks*, 352/ 0.0035-0.0055 wear limit 0.0065

330, 361 and 391/ 0.0025-0.0050 wear limit 0.0060
__________________________________________________________

Since all FE and FT engines are performance engines, these are performance specs.

They turned out to be terribly wide, so I got a set of oversized shafts from Doug,(POP) and got my clearance down to .002. Huge difference. .0015-.0025 is as tight and wide as I would go.