1970 351 Cleveland 4v d1ae ga heads (Jefferson hills) on craigslist in Pittsburg
Already has studs.
Not mine, just passing it on.
https://pittsburgh.craigslist.org/pts/5074424089.html
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D1 = 1971
those are 1971 heads, although I believe that is also the casting number for the "spares" Ford cast a few years later.
those are 1971 heads, although I believe that is also the casting number for the "spares" Ford cast a few years later.
That is the Crane rocker arm stud kit.
http://www.summitracing.com/pa...Sg6n9EFdoRoCO0Hw_wcB
They show 7/16" on the outside but are 5/16" mounted to the head where the bolt on rocker arm normally goes to.
This saves you from the effort and cost of machining the pedestals to the Boss302/351 style.
Personally I would not trust that size bolt, i.e., 5/16", on a high performance application. They will snap pretty easily if you raise the spring pressure to 350 to 380 which is what you normally would use with a high performance, non-stock camshaft and valve train.
Don't pay extra for that conversion that is shown. They are not reliable.
http://www.summitracing.com/pa...Sg6n9EFdoRoCO0Hw_wcB
They show 7/16" on the outside but are 5/16" mounted to the head where the bolt on rocker arm normally goes to.
This saves you from the effort and cost of machining the pedestals to the Boss302/351 style.
Personally I would not trust that size bolt, i.e., 5/16", on a high performance application. They will snap pretty easily if you raise the spring pressure to 350 to 380 which is what you normally would use with a high performance, non-stock camshaft and valve train.
Don't pay extra for that conversion that is shown. They are not reliable.
quote:Originally posted by PanteraDoug:
That is the Crane rocker arm stud kit.
http://www.summitracing.com/pa...Sg6n9EFdoRoCO0Hw_wcB
They show 7/16" on the outside but are 5/16" mounted to the head where the bolt on rocker arm normally goes to.
This saves you from the effort and cost of machining the pedestals to the Boss302/351 style.
Personally I would not trust that size bolt, i.e., 5/16", on a high performance application. They will snap pretty easily if you raise the spring pressure to 350 to 380 which is what you normally would use with a high performance, non-stock camshaft and valve train.
Don't pay extra for that conversion that is shown. They are not reliable.
...Ageed! Doug is Absolutely Right! Those things shouldn't even be on the Market, Period! Summit has opened themselves up to a great liability. In My Opinion, they are a Cheap Short-Cut to milling/drilling/tapping the Stud Bosses, That WILL FAIL the very first Day!!
Get rid of them! Or Sooner than Later...'It' will be Much More Expensive than doing the Machining, In The First Place! That Any Shop will do for $200.00....7/16" ARP Studs, less than $100.00
Local Pantera guy has had the Crane Rocker Arm kit on his Pantera engine for at least a decade. This includes many track days at various facilities. He has never had a problem with the kit. I too was skeptical when he installed them. However, I am no longer.
So are these concerns based on known failures or well intentioned engineering hypotheticals?
So are these concerns based on known failures or well intentioned engineering hypotheticals?
quote:Originally posted by JTpantera:
Local Pantera guy has had the Crane Rocker Arm kit on his Pantera engine for at least a decade. This includes many track days at various facilities. He has never had a problem with the kit. I too was skeptical when he installed them. However, I am no longer.
So are these concerns based on known failures or well intentioned engineering hypotheticals?
All I said was that I wouldn't trust them.
Show me how a 5/16" stud equals the strength of a 7/16" stud? You can't.
The 7/16" studs aren't installed on the Boss heads by the factory on a whim.
You want to defend them, be my guest. I am not that foolish.
Vote where YOU want to with YOUR MONEY. That's what I do...and that's how I pay for my mistakes.
quote:Originally posted by JTpantera:
Local Pantera guy has had the Crane Rocker Arm kit on his Pantera engine for at least a decade. This includes many track days at various facilities. He has never had a problem with the kit. I too was skeptical when he installed them. However, I am no longer.
So are these concerns based on known failures or well intentioned engineering hypotheticals?
...I'am NOT Concerned! It's NOT MY Engine!!
Hypotheticals? No! More like 45+ years of Machining Practice. I 'Think' I know Steels and Heat Treating along with just a 'little-bit' of knowledge In Physics and Engineering. LOL The 5/16' end, where it meets the Flange of the 7/16" Stud, 'barely' has any kind of a Fillet, at all. Not to mention the 'Sharp' Thread of the 'Minor Diameter'. OK, It did not snap on the First Day. But the man is racing on Borrowed Time. I'll take your word for it, that the engine has seen racing at higher RPM's.
The One thing I Do know is 'The Harder You make Steel, the Closer You get to the Brittleness of Glass!'. Here, I'am Not going to get into Annealing and Work Hardening.
When building Engines, I Believe in 'Massive Overkill'!! It'll Never be 'TOO' Strong. My point being...Why would anyone want to build a Cleveland Engine as WEAK as Possible?? And for Racing, No less?
So, go ahead a defend the use of these parts, I would love to see YOU put them in YOUR Engine!! Now THAT would Prove your No longer skeptical, and Not just BS'n.
"....Listen to Me now, Or Believe Me Later!".
The good news is that those stud-adapters can be removed, and the pedestals properly machined.
The picture of the kit that Doug posted would make me think twice about using them - just my $.02.
Rocky
The picture of the kit that Doug posted would make me think twice about using them - just my $.02.
Rocky
quote:Originally posted by Rocky:
The good news is that those stud-adapters can be removed, and the pedestals properly machined.
The picture of the kit that Doug posted would make me think twice about using them - just my $.02.
Rocky
I am not here to rain on anyone else's parade.
Crane created those studs as a solution to a specific problem of how to simply add adjustable rocker arms to the heads without removing the heads and machining the pedestals down and retaping them for 7/16" studs.
Consider what you are looking at, Marlins remarks and the fact that even with 7/16" studs many have found that even more strength was required in the valve train in the form of stud girdles.
The stud girdle ties all the studs together to act as a single entity in order to reduce flexing of the studs and thus stud fatigue and shearing at the base.
It is my opinion that the Crane kit will in fact work if the stresses do not exceed those of the ORIGINAL valve train.
That means original valve springs, original camshaft, original 5,800 rpm limit.
If those heads are off the engine (and that's what the pictures would indicate) remove the kit, machine the heads to the Ford specifications, install new ARP 7/16" x 7/16" studs.
Drop them off here. I'll do them for you. Ain't no BFD and I'm not a machine shop. Wait...no, don't bring them here, go to your local shop. Those things are too heavy to be humpin' around. I went 'luminum!
