Straight 6 4.1 250 l6
 

I'm looking for cylinder head bolts. I used 2 of them to lift the motor out and now I have 2 bent bolts. I should have used diffrent ones but I didn't think they were this hard to find.

You live and you learn :lol:

Re: Straight 6 4.1 250 l6
 

Get all new, never re-use headbolts !

Re: Straight 6 4.1 250 l6
 

Can't seem to find them. Do you know where I can buy them

Re: Straight 6 4.1 250 l6
 

https://www.summitracing.com/parts/f...BoCnW4QAvD_BwE

Call them to confirm but I believe these are the correct ones...

$ 18.99....

:chevy::chevy::chevy:

Re: Straight 6 4.1 250 l6
 

HeadBolts.com

Re: Straight 6 4.1 250 l6
 

[QUOTE=AussieinNC;8048014]https://www.summitracing.com/parts/f...BoCnW4QAvD_BwE

Call them to confirm but I believe these are the correct ones...

$ 18.99....

Wow if those are the ones I suck at searching because I spent an hour looking for them. Thanks alot!

Re: Straight 6 4.1 250 l6
 

They are oos

Re: Straight 6 4.1 250 l6
 

??

Re: Straight 6 4.1 250 l6
 

Out of stock

Re: Straight 6 4.1 250 l6
 

Head bolts for your engine are nothing special (i.e., not Grade 8 or single use stretch bolts). Just go to the parts store and get a couple with the right thread and length.

Re: Straight 6 4.1 250 l6
 

No they will not work they are for a 90s ford

Re: Straight 6 4.1 250 l6
 

Are you sure? They have a 3/4 inch wide area underneath the head thats wider then the rest of the bolt.

Re: Straight 6 4.1 250 l6
 

Cylinder head bolts are typically necked down and you get a set amount of stretch (preload) for a given torque. If you put bolts in with a different diameter, you will get a different preload for a given torque. Would it matter on a mild 250 Chevy? Probably not. Would I do it? Only if desperate.

I've re-used head bolts (if straight) on an inline build. As someone said, this application is not single-use. The fatigue life at 8.5:1 compression is probably infinite.

I've never heard of this website, but they say they have them in stock:

https://autoplicity.com/1255565-pion...ead-bolt-25pcs

If money's no object :eek:, there's an ARP stud kit:

http://arp-bolts.com/kits/ARPkit-det...p?RecordID=216

Re: Straight 6 4.1 250 l6
 

Thanks a lot helped out a ton!

Re: Straight 6 4.1 250 l6
 

Hi Shaky: I've never used head studs before. Does the fact that only the nut on top is turning, during the torque process have any effect on bolt stretch, vs turning the whole bolt itself? Or would it matter?

Re: Straight 6 4.1 250 l6
 

Generally speaking, bolts twist when torqued and studs don't twist nearly as much if properly installed. Here's what ARP says and it squares with my experience designing helicopter gearboxes:

"ARP’s factory Tech Representatives are often asked which is better, cylinder head studs or bolts. The answer, invariably, depends on the installation. On many street-driven vehicles, where master cylinders and other items protrude into the engine compartment, it’s probably necessary to use head bolts so that the cylinder heads can be removed with the engine in the car.

For most applications, however, studs are recommended. And for good reason. Using studs will make it much easier to assemble an engine (especially a racing powerplant which must be serviced frequently and quickly!) with the cylinder head and gasket assured of proper alignment. Studs also provide more accurate and consistent torque loading.

Here’s why. When you use bolts to secure the head, the fastener is actually being “twisted” while it’s being torqued to the proper reading. Accordingly, the bolt is reacting to two different forces simultaneously. A stud should be installed in a “relaxed” mode – never crank it in tightly using a jammed nut. If everything is right, the stud should be installed finger tight. Then, when applying torque to the nut, the stud will stretch only on the vertical axis. Remember, an undercut shorter stud will have a rate similar to a longer, standard shank stud. This provides a more even clamping force on the head. Because the head gasket will compress upon initial torquing, make sure studs and bolts are re-torqued after the engine has been run."

Re: Straight 6 4.1 250 l6
 

Thanks Shaky, that was quite informative.
I've had problems pulling the head on a 292 L6 -- which is almost 2'' taller than the 250/230 block -- when using head bolts. Studs would add a degree of difficulty, although mechanically superior.
I believe I have re-used L6 head bolts w/o issues. I built for low compression to use 87 octane pump gas.
[There was one head bolt that had a stud coming out of the top of the hex head cap, factory item, for mounting some accessory (A.I.R. IIRC), but I conveniently lost it.]

Last year when doing a full R+ R on my valve springs, I also had issues getting to cylinders # 5 & 6. Modified the pry-bar style of spring compressor by drilling and shaping a keyhole in the middle of the prybar so I could use it 'backhand'.

Re: Straight 6 4.1 250 l6
 

Yeah I'd imagine that the studs on an inline would probably make in-vehicle had removal more difficult. On a v-8, in most cases, it makes it easier. Sure helps the gaskets stay in place!

I've never removed a 292 head in-vehicle, only a 250. I imagine that extra block height adds some degree of difficulty.

Re: Straight 6 4.1 250 l6
 

>>I've never removed a 292 head in-vehicle, only a 250. I imagine that extra block height adds some degree of difficulty<<

By itself, removing the 292 head is no different than the 250. but there is a slight problem to be encountered with the ~ 11.4" long push rods. The push rods for #6 will not clear the cowl.
When removing the head you can leave the last two push rods in the block until you pull the head out.
Reinstalling the head requires a little finesse, because those rear pushrods have to be installed first and care must be taken not to damage or bent the push rods. You either need an extra set of strong hands or a cherry picker.
I've set the head on the block, several inches forward of where it needs to go. Standing on the frame rails, straddling the engine, you can then lift the head up, back and gently lower it over the push rods.
Nice thing about a six. There's plenty of room to climb in there when needed.

Re: Straight 6 4.1 250 l6
 

You could -- if desperate enough -- drill 1'' holes in the doghouse alcove (?) for the pushrods to have more headroom, but you'd probably cause big problems in the underdash anatomy, not to mention sealing issues.
Another alternative might be to disconnect the driveline at the transmission [SM465], loosen mounts there, dismount the engine at its mounts and allow the engine to be lowered in the front. This would require releasing all radiator hose connections, possibly pulling the fan, fuel line, etc. More trouble than it's worth. I think I did it as RichardJ describes. It was a long time ago. [late '70s, early '80s, ICRS] Since then I try to overbuild the head when the whole block is out, to prevent failures.

Re: Straight 6 4.1 250 l6
 

IN almost 1 million miles and 3 rebuilds I never had a problem reuseing headbolts. I have some if you need a couple. pm me

Re: Straight 6 4.1 250 l6
 

What length of bolts do you need?