Is there any advantage/reason to use hardened washers under the bolt heads if the heads are going on and staying on? (No regular R&R like racers do)

How important is retorque once the engine has been run, when reusing the bolts that were already on the car? I will be using Victor Reinz composite .026" gaskets. Same old heads, also, not new heads

I used to retorque all the long bolts and whatever short bolts I could get to without undoing the headers, but now that there is more *stuff* that has to be moved to get to the valve covers off, it can be a pain.

Were production motor headbolts ever retorqued at Chev prior to sending the car out the door? I don't think they were.

Thanks,
Doug

 

Washers are not needed unless you have aluminum heads.

If it makes you feel better then re-torque them, but not necessary.

 

Washers are not needed on iron heads.

Don't forget to put some gasket sealer on the head bolt threads that go into the water jacket. Gives a more accurate torque figure to boot.

Upon tearing down several original Chebby engines I have observed what looks an awfull lot like 3M weatherstrip adhesive on the head bolt threads. Streatchy, rubbery stuff.

 

There is an advantage as far as torque accuracy and they will keep the contact area from getting rolled over into the hole but for a mild street engine there not nessasary. I always follow the recommendation of the gasket manufacture as to weather to retorque or not.

 

AZDoug, You probably already know this, but for others on the board, the most important thing is making sure the torque wrench you use is in calibration. They can go out of calibration over time or when dropped. Secondly, the heads and gaskets should be re-torqued in stages and in a specific pattern from the inside bolts to the perimeter bolts and front to back of the heads. Normally a manufacturer will have specific recommendations for the torque sequence, but the stages of torque should be roughly 30 pounds, then 50 pounds and finally 70 to 75 pounds.

Since I always use Fel-Pro Perma-Torque head gaskets, I've never re-torqued head bolts and never head a sealing problem.

 

Retorque of steel, and most newer comp head gaskets, is not required, or recommended. Retorquing "some or most" of the head bolts is definitely not recommended. This disturbs the original "even torque plane" that was established when the head was initially installed.

The correct sequence for head bolt torque always begins as close to the center of the head as possible and, in a circular pattern, works it's way out toward the ends. I can scan/post the correct sequence if you don't have an overhaul manual.

If you had your block "deck plate honed", it's also critically important to torque the cyl head bolts to the exact same figure that was used when the boring/honing was done.

 

I have a beam type torque wrench.

I don't think those go out of calibration unless they are damaged, correct?

No copper sealer (or other sealer) on the composition gaskets, correct? They didn't come with instructions.

I am very glad I purchesed an air ratchet some years ago, all those rocker arm bolts and head bolts would be a real pain to off/on again manually like I used to do it.

I have the head bolt sequence.

Thanks,


Doug

 

I don't think a beam style torque wrench would change calibration much over the years but I much prefer a click type over the beam for head bolts. In this case, the consistancy is more important than absolute accuracy. A few pounds off for all the head bolts, as loing as their all off by the same small amount, is better than a variety of different torque settings from bolt to bolt, especially if you honed with deck plates. Most engine builders insist on using the exact same torque wrench when installing the heads that they used to torque the torque plates during honing. That may be going a little over board for street use but you get the idea.

When you torque the head bolts, it slightly caves in the top of cylinder near each head bolt. As the torque is increased, the amount of cyl movement increases, especially when you near the range of the recommended torque setting. If torque plates are installed prior to honing, the bolt simulates the distortion of the cyl and the honing makes that area perfectly round. When the heads are installed, the bolt willl pull the cyl right back to the perfectly round shape that was created during honing. Pretty sure ALL the new car mfg's use this process today. I would never consider building an engine without it.

If the new comp head gaskets don't include instructions, I would definitely look into the matter. Most of todays comp gaskets require no hot retorque but some of the "off brands" may. If you find that the set you have does require a retorque, I would consider a different source for gaskets. Lot of valid reasons why the retorque style is not desireable.

Not trying to create a lot of extra work for you but... using an air tool on rocker arm nuts is a quick way to destroy the prevailing torque that was built into the nuts. If your air ratchet turns somewhat slowly, you should be ok but if it's powerful and spins the nuts at high speed, you may have to "recalibrate" the nuts. (I've seen this done with a hammer but I'm not recommending it) If it's a 3'/8" drive, I'm pretty sure you'll be ok. It's usually the big 1/2" drive impact wrenchs that to the damage.

 

This is an old motor with a cam change, no torque plates.

It is an air ratchet, not a high speed impact, it goes about as fast as a socket wrench would if you spin it around by hand with no resistance, ie, about 60 RPM

Thanks,
Doug