A new torque wrench is an unknown, maybe right, maybe wrong. Is there a rental place near you where you can rent a wrench? Many parts houses have this service. Do you have a friend that may have one you can borrow to verify? At this point, I would check torque and go no more than specified. If you found the torque was as specified, I would bite the bullet and pull the head. Come on, someone with more Y block build experience, please weigh in on this. Unless your wrench is way off, I suspect you have other problems.

 

Is the leak near where the new dowel went?
Have we verified the later heads are compatible with the older Y block?
Is the bolt differences due to the heads or the block differences?
I do not know.

 

I hate to be a buzzkill but if the dowel length is in question I would advise removing the head to be certain. If too long there is a possibility of cracking something (not that I've seen it happen, just thinking what could be the worst thing to occur.) I realize it's a PITA but, for the price of a few gaskets and some extra labor, there's that peace of mind thing to consider. Before removing anything use a pressure tester (if necessary) to see exactly where the leak is coming from. No use pulling a head if it's leaking from the manfold.

Re-torquing means added torque, not loosening then re-torquing. And only torquing the easy bolts is not good practice nor is not re-adjusting the valves afterward. If re-torquing actually moves the head closer to the block the valve adjustment will change, making the clearance tighter. Tight clearance can cause valve burning. I know this is all a pain but this sort of stuff happens to pros as well and you wouldn't expect them to take short cuts just because it didn't come out right the first time.

 

Yes, the leak is at the rear of the head (as far as I can tell) and that is where the new dowel went.

The heads were from Pinto plumbers 54 engine.

 

Thanks, Beav. My brother in law said the same thing about doing a pressure test first. Do you think I can rent a pressure tester from Advance Auto?

Thanks. Beav and Ray.

 

Where did you purchase the new dowel from ? if it was at a local parts house go purchase another and measure it with a micrometer, If it was mail order, call the supplier and see if someone can measure it for you. Although nothing is guaranteed by doing this, it may just give you some insight and lead you in the right direction.

 

At this point, the only thing a pressure test will do is confirm what you already know. Have you tried working a thin feeler gauge between the head and deck in the area of the leak? This might confirm the dowel is holding the head from seating to the deck. Have you tried retorquing the head and what was the result? If the retorque yields no further movement, it is time to pull the head. Not what you want to hear, I know.

 

I bought it from Crosby Machine online. I bought a pack of 4. So I can measure one of the 3 I didn't use. Do you know what they should measure?

 

Would a pressure test tell me exactly where the leak is in the head? Or just that there is a leak?
I didn't work on it today. I can tomorrow.
I haven't tried a feeler gauge.

I am afraid if we already torqued the bolts to 75 ft lbs if I set the wrench at 75 I risk snapping off bolts.

The first thing I must do though if I do a pressure test is to get the broken bolt out of the T-stat housing and replace it.

If I remove the head do I have to use a new gasket?

 

Abe, if the bolts are already torqued to 75 lbs, re-torqueing them to 75 lbs will do absolutely nothing. If they aren't torqued to 75 lbs, then they will be when you retorque. Torqueing them twice doesn't equal 150 lbs, it's not an additive process or anything like that. Not a cause for concern!

 

I know that it won't equal 150, but if they are already at 75 the torque wrench won't click since its already past 75?

 

No. The wrench will still click at 75 lbs regardless, if they are at least 75 lbs. They shouldn't be at more than 75 lbs, unless of course they were torqued to more than 75 lbs. I'm sure you know this, but a common error is folks will just keep truckin' on with the wrench after it clicks. Don't do that!

Keep an eye on the wrench and see if you're able to actually tighten the bolt further before it clicks, that's your indication they have loosened a little. That's what a retorque is, just to make sure they haven't loosened.

With exhaust manifolds for example, it usually takes a couple-few retorques for them to settle down. Heat cycles. Check them hot and cold. Modern head gaskets are designed, I guess, where retorques aren't required. But, it won't hurt a thing to check.

 

I borrowed a digital caliper from my local garage.

The dowels (one of the extra ones, not the one I put in the block) I bought measure .428" high or 10.90 mm.

does anyone know what they should measure for a 1954 239 Yblock?

 

Sorry, but the term retorque requires that the bolts be loosened and then retightened to that torque, the term for what you are describing is known as a torque check, in which an individual is basically making sure that none of the bolts have loosened off. Just figured I would clarify in case it did ask for a retorque as opposed to a torque check or a sequential torque.

 

Also a common problem when it comes to torquing a bolt is known as shotgun torque. It is there the individual is rushing the torque, which will set off the torque wrench early, proper procedure is to apply a slow steady torque, avoiding changes in speed, often it is followed by a check torque, where you remove the torque wrench spin the socket to remove any preload on the device from the torque and to then slowly check that the bolt is at that value.

Now in most businesses Check Torque is defined by "two or more successful torques without movement. If there is a movement then it's possible that the bolt isn't holding torque, either because the threads are stretching (from being worn out or a manufacturing defect) or that the bolt is not up to the actual torque. If you do several retorques and it moves every time it's more than likely that the bolts threads are stretching and that bolt is no longer serviceable. It is quite common though that after running the vibrations free up the bolt a hair and allow very minor movement, and all this means is that the bolt isn't settled fully at that torque. A common example of this is when tightening a band clamp. Proper procedure is to torque, (usually at 18inch/lbs) and then tap the band clamp with a soft faced mallet, this allows the clamp to settle further into position and then retorque. 95% of the time it will move. With the heads it's basically that same effect though now you are taking into account the compression of the head gasket. It will only compress over time a fraction of a thou after initial torque, but that will still change the value of the torque that is on those bolt heads.

Just figured I would give insight into the world of torquing to those unfamiliar.