2f head installation

[Webster]

I seem to have a chronic head gasket problem, wondering if my installation procedure could be contributing.

Anyone care to share their tried and true installation procedure?

How about what you have found to work on adjusting the valves?

Thansk!

 

[Pinion]

I torque according to the manual. Use which ever thread locker they tell you to.

I set valve lash as it is suggested in the manual.

These two things are pretty straight forward.

Have you had head problems before?

If so, have you had the head decked?

 

[Webster]

I have both manuals (Chiltons, Haynes) and they both vary. Neither mentions a threadlocker. One suggests valve adjusting while running and the other while cold and not running.

Is there a need to retorque the head bolts after running a while?

 

[Webster]

This is a rebuilt head just a year old.

 

[Pinion]

Get the engine up to running temp and then set the motor to TDC. Do 1/2 the valves, and then rotate 180*, then do the other ones the manual tells you to. Dont set it while running, its not necessary.

The threadlocker for the head will let you get the correct torque and wont back out so you wont have to re tighten it. Tighten 'em down and let it set up, just make sure you dont use the super heavy duty stuff. Some high temp stuff works best. I also use a thread cutter to clean out all the crap that can collect down there.

 

[Pinion]

[quote author=Webster link=board=1;threadid=4192;start=0#msg31070 date=1060363470]
This is a rebuilt head just a year old.
[/quote]
Was it decked though? It isnt a normal part of the process. Some shops will just rebuild them and ask if you want it decked. If it isnt totally straight/flat, you will have gasket problems.

 

[petescoffee]

Check the head for flatness. Just because it was redone doesn't mean it is flat. Also Check the block for flatness. When I rebuilt my 2f I had the block decked as it was out. Do not use A file to flatten out the deck on the head or block.
Also, very important, Retorque the head after start up and again after 500 miles. Do a search on the lcml for Mark's W. comments regarding this. I spoke to another LC Guru and he said the same thing and not retorquing is one of the most common reasons he see's blown head gaskets from people that do it themselves, like me.
good luck.

 

[Chef]

It should be standard procedure to re-torque cylinder heads after 2 or 3 heat cycles, and again at 550, and 1000 miles. This may sound excessive, but SAE and other engineering studies have shown that fasteners can lose as much as 10% of their torque value just sitting there for 10-15 minutes, and even more than that after several heat cycles. It is a good idea to check both the block deck and head for true...

 

[hammerhead]

Retorque. Makes sense to me, I mean, I have to do it to my race bikes. All the retorques in the world won't do any good for a warped head though.

 

[dd113]

Yes, you should torque the bolts again after a few cycles but I never seem to get around to it. All my motors are fine. One item that i have found healpul is a compression washer. I use them on all old heads. Costs around a $1 a bolt.Allows you to torque it down then it stays there. Also makes up for any slop in the head if it as been decked mutiple times.

 

[techninja]

Do you retorque the head when it is hot?
This is what Man-A-Fre says they are going to do when they adjust the valves...head is still original w/199k miles.
Seems weird to me, but the last rebuild of a car I did (which involved r/r a head) was a 1957 Borgward, and the only other one was a CB 500 four Honda...

 

[matt.mcinnes]

Are you using a genuine head gasket or after market?

 

[bsevans]

First, did you buy a tap to chase the threads in the block? If not, you will not know what the torque on the head really is. You will be amazed at what comes out of the bolt holes in the block You can test the bolt holes in the block by threading a head bolt into each bolt hole by hand. If you cannot easily screw it in by hand then the added torque required to just thread the bolt in is torque that would need to be compensated for when installing the head. You can buy the tap at mscdirect.com. Personally, I would never use thread locker on the head bolts. You're better off using a light lubricant. I've never seen in any FSM a call out for thread locker on head bolts. I might add, I've never seen a head bolt come loose. The older head gaskets (dimpled metal) require that the head be re-torqued after the engine has been run for a limited time. The newer head gaskets supposedly do not require the head to be re-torqued.

 

[Degnol]

This ought to be good....we can get a 5-year followup on his success/failure

 

[donny paradise]

Are you using a genuine head gasket or after market?

First, did you buy a tap to chase the threads in the block? If not, you will not know what the torque on the head really is. You will be amazed at what comes out of the bolt holes in the block You can test the bolt holes in the block by threading a head bolt into each bolt hole by hand. If you cannot easily screw it in by hand then the added torque required to just thread the bolt in is torque that would need to be compensated for when installing the head. You can buy the tap at mscdirect.com. Personally, I would never use thread locker on the head bolts. You're better off using a light lubricant. I've never seen in any FSM a call out for thread locker on head bolts. I might add, I've never seen a head bolt come loose. The older head gaskets (dimpled metal) require that the head be re-torqued after the engine has been run for a limited time. The newer head gaskets supposedly do not require the head to be re-torqued.

Who are you 2 cats replying to? The thread was brought back from '03. techninja ask about re-torque hot or cold... 2/27'09

 

[Pin_Head]

Check the head for flatness. Also Check the block for flatness.

X2

If it has failed repeatedly one of them isn't flat.