head bolts 51 f1 8ba

[51secondchance]

hello can any one please tell me if I'm nuts or just paranoid I'm putting together my 51 8ba engine and I'm to the point of installing the cast iron heads and a lot of post i have read says 55 to 60 lb. torque but my ford book says 65 ,70 ft lb. its not a rocket engine I'm just curious if the reason most people go lighter and retorque after run in a couple times is to minimize warpageor has everyone from experience found that 55 to 60 is just fine ?? thoughts please

 

[JWL]

Never more than 50 ft. Lbs. on any style head. Even at 50 lbs. the block face has created thick-thin conditions within the gasket. Re-torque after heat, then cool cycles.

 

[Charlie ny]

51,
End of story, John knows.
Charlie ny

 

[19Fordy]

Used head bolts can stretch. Stay on the low side. I remember a head bolt suddenly getting easier to tighten and I was able to back it out. You could actually see where the bolt began to 'neck down".

 

[Ol' Ron]

It's important to realize that you have to re-torque after at least 3 heat cycles. By that time everything is in a nice comfortable place. AND, it really doesn't matter what king of head your using.

 

[jack orchard]

It's important to realize that you have to re-torque after at least 3 heat cycles. By that time everything is in a nice comfortable place. AND, it really doesn't matter what king of head your using.

I agree. What thread sealant would allow these re-torque events without becoming hard and causing coolant leaks.,...jack

 

[Ol' Ron]

I use a goop for steam pipes, Been using it for years and it never hardens.

 

[vilanar]

When re-torquing do you back up the bolt a little before torquing ?
If not , doesn´t force to overcome the tension/friction already there give false reading ?

 

[19Fordy]

vilnar: Bolt head friction must be overcome if you tighten or loosen a bolt. Some folks say "loosen bolt first" and then retorque and some say " do not loosen". It would be interesting to experiment and see if there is a difference. Remember, some modern head gaskets do not have to be retorqued, so check with manufacturer. Here's a really informative article.
http://www.enginebuildermag.com/2005/07/perfect-engine-sealing-starts-with-proper-head-bolt-use/

 

[GOSFAST]

Just a tip for what it's worth.

We strongly recommend using washers under ALL head bolts, even the OEM factory pieces. Most stud kits (aftermarket) come with the washers provided, most factory head bolts don't.

They aren't all that expensive and they provide a much greater surface-contact area for the castings.

We have a number of head bolt boss issues with the SBC's due to the lack of that area for the head bolts and they are very similar to the Flatheads.

Thanks, Gary in N.Y.

P.S. Here's a couple shots of the Flathead bolts/washers and one of the SBC bolt bosses we see from time to time. When we do any builds here using OEM (previously used) castings we always provide a new surface for the bolts/studs by spot-facing the original bosses.

 

[El Rat]

Re-torgue as often as required. When the bolt quits moving (after heat cycle) you're done with re-torque.
AV Permatex works great stays plyable.

 

[Ross F-1]

Just a tip for what it's worth.

We strongly recommend using washers under ALL head bolts, even the OEM factory pieces. Most stud kits (aftermarket) come with the washers provided, most factory head bolts don't.
....

I'd be wary of hardened washers on an 8BA, from the standpoint of reduced thread engagement. The hardened washers I've seen are like for 59-series engines, and probably thick enough to lose 3 - 4 threads into the deck. Do you use longer bolts with the washers?

 

[GOSFAST]

I'd be wary of hardened washers on an 8BA, from the standpoint of reduced thread engagement. The hardened washers I've seen are like for 59-series engines, and probably thick enough to lose 3 - 4 threads into the deck. Do you use longer bolts with the washers?

Hi Ross, those washers above are .060" (nominal) thick, you won't give up 1 full thread! The photo below shows the thickness, it is really a negligible amount of thread loss.

I put another shot below showing the bolt sitting in the washer. Having said this we do use .125" thick washers but not on the stock length bolts.

Thanks, Gary in N.Y.

P.S. There's nothing gets posted up here that hasn't been thoroughly tested by us between the dyno and customer feedback.

 

[Ross F-1]

Thanks Gary, the ones I've seen were beyond 1/8" thick. Like used on aluminum heads.

 

[TStiles]

ARP makes an outstanding head bolt set for the flatheads. These bolts are slightly longer than original and come with washers, so the net is standard length. They're stainless.