The great "oiling" headbolt debate!

After seeing new headbolt post about the chevy 235, and knowing for sure that none of my bolts are the oiling kind, I called Landon's Stovebolt Engine company and asked an expert, about the finer points of lubrication on a 235 top end..

According to Tom,

Not ALL 235's rely on the oiling headbolt. Some of them don't have any drilled headbolts at all. To find out if your engine requires the special headbolt, you'll need the casting number on the engine block. The block determines the need for the special headbolt regardless of what casting your cylinder head itself is. The block number can be found on the engine near the rail for the oilpan on the fuel pump side. I'm e-mailing my number to him and he'll be able to reference it and let me know if I need the bolt or not.

web page with contact link

He did mention that it's a good idea to test if your cylinder head is oiling properly buy turning the oil pump with aid of a drill and parts from an old distributor (not sure of the specifics on that one). He also mentioned that it sometimes takes some time for the oiling to get going when doing this, but it's worth checking before firing the engine.

I'm going to look up my casting number this weekend and let you know what he says about the bolt. My engine is out of a 59...

Hope this is helpful!

Stacey

 

Maybe I can offer a bit of clarity on the "distibutor as oil pump priming tool" issue for ya.

If you have a shot distributor, you can pull the drive gear off of it and use the remaining guts (minus cap and all) to spin the oil pump without the engine running. This will allow you to pressurize the oil system prior to firing the engine, which ensures all the critical surfaces have adequate lubrication. To do this, chuck the remains of the distributor drive shaft in the drill, and with the distributor removed, slide it into position so it engages the oil pump drive shaft (should look like a screwdriver head). Now when the drill is running, its spinning the oil pump and providing pressure. You should have an oil pressure gauge hooked up and you should get a reading when the drill is running. Have a pal turn the engine over by hand using a breaker bar and the appropriate socket on the big crankshaft bolt going through the lower pulleys. As your friend is turning the engine over manually (pull out all the spark plugs to make this chore easier), the engine will get full oiling over all surfaces and the oiling system will be functioning exactly as it will once the engine runs "for real". I like to do this with the valve cover off to see all the rockers getting their fair share. Flow should be steady and even across all the rockers as the engine is being manually turned over.

If you need the hollow head bolt and you don't have it, you won't see oil getting to the top of the engine. If you see oil generously flowing over all the rockers, you're in good shape and all is well. Replace the valve cover, spark plugs, and distributor once you're satisfied with the oil flow, and now you'll know when the engine is fired up that everything is getting lubed right. You'll also know you've pre-oiled all the good stuff before firing, so nothing is running "dry".

Hope that helps a little.

They have tools to make this easier for many engines (especially small-blocks), but an old distributor workd just fine when a pre-fabbed part isn't available.

Scotch~!

 

Thanks for the how-to! I'm definitely going to do this..

Stacey

 

just take n old dist and grins the teeth off the cam gear. keeps the shaft in place, allows it to turn the oil pump without the cam turning.


jerry

 

Here's a shot of the 1962 235 in my shop.
Note the location and the groove on the oiling bolt.

 

Here's a couple of oiling headbolts.
The one on the left is a stocker.
The one on the right is the home made version.
Note how much larger the passage is, this will allow a lot more oil to flow up stairs.
I'm certainly no expert, but every 235 and 261 I've pulled apart all had the special headbolt.

 

Well... I sent my engine block number to Langdons and was told that I don't need the special bolt on my cylinder head.

We're going to do the drill trick and I'll let you know if it oils properly... If it does, then Langdons may be a good resource for checking this out on 235's..

Stacey