New Engine Assembly: Head/Block Alignment Dowels

The questions won't stop here but this will get me started. This is my winter project 2013. I'm in no hurry so I thought I'd ask the considerable Buick minds here what my next plan of action should be. I'd rather do it right than quick since the motor in the car runs just fine.

Do I need the deck dowels? Where can I get them or what is compatible? Can I just use a long piece of all-thread to align the heads and gaskets?

The back story:

I have managed to gather enough parts to start assembling an extra motor and ran into a slight snag. This is my first Buick motor in 25 years and that one still runs pretty good. I just came upon enough parts to assemble a fresh one with all the things I didn't have available 26 years ago and wanted to get my hands dirty again.

Bought the never-started short block off a member here with forged pistons and a TA212 cam. It is sitting on the engine stand. Last year I bought a set of never-run Edlebrock heads and rocker arms off a member and was going to set the heads on the block this weekend with my Felpro blue gaskets. It was THEN I noticed the block has no alignment dowels on the head surface.

Thanks

 

You should use dowels,get some 1/4" steel rod,cut a couple pins about 1/2" taper the ends slightly and pound them in
gary

 

Just to add to Gary's post, after you install the new dowel pins set the head on without a gasket to make sure the head sits on the block correctly. Chris

 

Ah, well, that should be easy enough to procure. I see TA has them for a $1 each. I need a few other things as well so I'll through them in to the cart.

Will do. Today was just a test fit day any way. Still procuring the odd and end parts like the intake fittings and hoses.

What thermostat would folks prefer in an aluminum headed 455 .030 over with a TA212 cam?

 

Greg Gessler sells them.

http://www.gesslerheadporting.com/g...01ecd25ebb29723785257299001976dd!OpenDocument

 

Greg,

Buick 400-455 dowel pins are unique, they are not .250 (1/4 inch).

They actually measure .247, and that .003 is the difference between the parts fitting together easily, and forcing them together.

The Pioneer number for a box of 100, for those of you interested, is PG-695-100.

I found this out years ago after struggling with a set of .250 pins on a motor. Nothing fit right, had to be forced together.

A small detail, but an important one.

JW

 

Oh, already got some from Lowes. I suspect I'll try one just to see for myself and return them if they are a big pain. Good to know.

 

The block holes are about a .001 interference fit.. so it will be impossible to tell by trying them in the block. The correct dowels go in the holes with just a light tap from a small hammer.

But check the timing cover dowel holes, the heads, and the head gasket dowel holes. The pins have to fit in them, with just your finger.

You can use those 1/4 dowels, by using a 1/4 drill to ream the holes out slightly. But be careful putting them in the block, with a .004 interference fit, it's easy to bend plain steel, if that is what your using. You can ream the block holes out with that drill, that is probably safer then trying to beat them in. Plain steel won't take that typically without mushrooming over.

Dowel pins are ground and hardened.

If you have the capability to turn a few thousandths off plain steel, then you can in fact make them from hardware store plain steel rod. Dimensions for those pins are .247x.510 long.

Just so you know what the issues are, there are several ways to solve them, with local materials. You would have to mail order Buick dowel pins, I don't believe you can buy just a couple. Years ago I had to buy a box of 100, as all my motors get new pins thru-out.

You can get Chevy pins from MR gasket in small quantities, but they use a .316 diam pin.

You probably can figure this out, the head/block dowels are the easiest to fake with something else.. but when you start talking timing cover and water pump dowels, you can get in trouble really quick trying to use the wrong ones.

That's really why I replied here, not that anyone was trying to steer you wrong on this particular deal.

Come to think of this, if I had to do this job in a hurry without waiting for dowels, I might try and use 1/4 roll pins from the hardware store. They probably would tap into the block nice, and that extra .003 would not be a problem.


JW

 

Or,if you get 1/4" dia. X 1/2 long dowl pins,you could chuck them in a drill motor(one at a time) and use some 180 grit emery cloth, to sand down the dia. to .247". You will need a set of 0-1" mics to get the proper dimension,when you get it down to .247" flip it over in the drill motor and do the other side.

The correct pins would be the better way to go,but if you can't wait this should work in a pinch. It may take some time with a hardened dowl,but not as long as waiting for them in the mail. GL

 

Interestingly enough, they fit in the Edelbrock head with no issues as shipped. Will try the block in the morning and see how it goes.

 

Wow what great news Jim!. I'm sending my 350 block to the machine shop and havent tried to take the dowels out yet but now I want to label and save all dowels. Any good tips on getting them out without destroying them?
I thought they were a standard size.

 

Have the machine shop remove them with a removal tool.. looks like a slide hammer, with a collet that tightens on the pins to keep from damaging them.. and then have them save them.

JW

 

I have a couple of slide hammers I will see if one of them fits, I never thought of that! Since you have some of that machine experience, I have an old piston pin hone that I got off of ebay and the sandpaper needs replaced. Do you buy the halves of the hone new with paper installed or glue new paper on them. Sorry Jim but one more question, I need some more clearance between my connecting rods on the big end. I will take .001 off of the side where they meet on the crank. Would you mice them and use a belt sander to remove the metal or use another method at the machine shop.

 

Ron,

Not sure on your hone question, never delt with one like that.. I am familiar with the sunnen LB 1660 type manual rod hone, but it uses stone shoes.

On increasing rod side clearance.. ask around and see if you can find someone with a magnetic grinder.. this is a vertical grinding machine that has the rods set flat on magnetic table (assuming they are steel rods). This is the best method for holding a tolerance like your talking about (.001), and keeping everything flat and square.

Every time I have seen someone try and use a belt sander to reduce the thickness of the big end of the rod, the results, while workable, are no where near as uniform as the mag grinder will produce.

JW

 

Can't afford anything like that until I start my own race car business which I want to do but until then I can be within .015-.020 so I will ask Danny Quinlin at his machine shop what he wants to do it or I will do my best to keep them flat on the sander. Where can I buy that hone that you are talking about for the piston pin and the small rod end bores to size the rods and pistons to .001? I have already done it with the hone I got but it's not the quality in a tool that I like. I love to do everything myself because I don't want my Buick parts destroyed by someone who thinks it's a Chevy.

 

I wasn't suggesting that you should buy that sunnen rod hone Ron.

Resizing the big end of the Buick rod is a pain, but pin end sizing is simple, couldn't see that being an issue at any competent machine shop.

Ditto with sizing the pin hole in the piston.

JW