I put coolant in my 54 today. Started it up and saw that I had a leak at the thermostat housing. I shut off the truck and tightened the bolts. And, you guessed it, I broke off one of the bolts! Ugh!

Then I saw coolant dripping off the back of the engine. I thought it was from the T-stat housing leak. It kept dripping. Upon further inspection I could tell it was coming from the head!

So I plan on retorquing the head bolts. After I get the bolt out of the housing and get it replaced I plan on getting the engine up to temp and then torquing the bolts outside the head to 75ft lbs.

Any other advice?

 

I feel your pain, Abe. Make certain your bolts into the manifold and thru the manifold are not too long.

 

I totally agree.
And make sure the threads are clean and there isn't any rust or dirt in the bottom of the hole

 

Forgot to mention, retorquing the heads on the Y block is a PIA. You have rocker shafts interference to contend with. Did I say, PIA But, I know we're having fun, aren't we, Abe?

 

We used the same bolts that I took out of the manifold.

My BIL cleaned the threads and then blew them out with compressed air.

Yes I know... Must the rocker shaft come out to do the top bolts? My BIL thought I should first just tighten the lower bolts and see if that solves it.

I am done for the day. We had to go to a memorial service, but the top ones are a PIA but can they be tightened without removing the rocker shaft?

The shop manual says to tighten to 55 then 65 and then after getting the engine warm then 75 lbs. That would be a real PIA if the rocker shaft must be removed to tighten the top bolts. Do the valves need adjusted if your remove the rocker shaft?

Last question for today: do I need to loosen the head bolts I retorque them, or should I go psat 75lbs?

Thanks, Ray and Mixerman!

 

Abe most Y Blocks have three different bolts. It's easy to get them mixed up.


56 and newer Y Block head bolts.

 

Too bad there are problems. Isn't that always the way things go. Just when you think you are maybe ready to tackle some things on your own, something like this occurs. Maybe BJ is on to something with the different size head bolts. Good luck sorting things out.

 

I'm not home now to check my Eickman Yblock book but I think it said 56 and up heads have longer bolts at the ends. 54 and 55 bolts are all the same.

Thanks.

 

The top ones in a 54 are the same length and the front ones are the same length. Eickman says 1956 and later engines had longer end bolts as shown in BJ'S picture. And now that I think about it I went really **** and put the bolts in the top of a cardboard box to keep them in order and also separate from right and left.

 

Abe, all the head bolts should be torqued to the specified torque in sequence. IMO, the valves will be alright for a while. They should be readjusted after a thousand miles or so. I don't remember what the recommendation is. Sometime prior to the Truckstock trip.

 

Ok, so I will torque them as the shop manual says.

#1 Is it okay to loosen the bolts a bit and then torque them to the specified ft lbs so I don't overtighten them?
#2 Should I get the engine up to temp and then tighten to 75 as the shop manual says?

 

Abe, I make no claims to be an engine builder although I have built several Y blocks.
1. It is my belief that a head bolt should not be loosened but torqued to specs and in sequence. The Y block design has been criticized for having so few bolts which, IMO, makes torque and sequence more critical. Is your torque wrench known accurate?
2. The shop manual was most likely written for steel head gaskets. I would assume you are using a more modern design gasket that may change the retorque requirements.
When I built MG, I used the modern composite gaskets and I did retorque them.
I know, I am not much help.
Edit: If I were where you are right now, I would torque the head and unless I found it very loose, I would pull that head and double check. You did verify the gaskets are installed correctly as mentioned in the link you provided earlier, did you not?

 

You did verify the new dowels were the same height as the originals, did you not?

 

My answers are above in red.

 

I did not.... and when I told my BIL about this that was one reason he came up with. And the leak is the side that got the new dowel.... and if the leak is in the rear which I think it is that is where the new dowel is. I put the dowel in place and tapped it in with a hammer.... I assumed since I ordered dowels for my 239 1954 engine that it was the correct size. Like president Reagan said, "Trust but verify."

I am afraid that might be the problem..... So shall I try to re-torque the head bolts or just take off the head and start over after making the new dowell shorter?