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Wed Aug 13, 2008 5:45 pm

so, my boston bob 1600DP has been running pretty good. i was talking to a couple people at the terryville show who reccomended a retorque, did a search here and came up inconclusive. i will say, i never retorqued the last engine i had him do, and never had an issue. thoughts?

Wed Aug 13, 2008 5:49 pm

If you do it, remember to do the top studs which require taking the cylinder tin off.

Wed Aug 13, 2008 7:51 pm

hey glenn~ yea, i realize that, but it should only take a couple hours. just wondering what the general consensus is on this

Wed Aug 13, 2008 7:56 pm

i never do on a stock or stockish engine. but on all hi-po engines i retorque after 500 miles. don't ask me why, just something an old timer said i should do.

Wed Aug 13, 2008 8:02 pm

So I have about 3000 on a fresh 1600 rebuild....do you recommend I retorque them (top and bottom). Its on a baja so it will be a litttle bit easier.

Wed Aug 13, 2008 9:01 pm

if it sounds like your heads are loose... then do it.. if not dont even worry about it.

Wed Aug 13, 2008 10:23 pm

On my Bug engine, I tried to retorque the heads after the first run. Nothing doing, I couldn't get them to budge from where I had set them before. My guess is because there's no gaskets to settle or anything like that, unlike a waterpumper. I had to do it on my Corvair engine though- I found out because I was trying to adjust the valves (rockers are on a combination head nut/rocker stud arrangement), and 4 of them were on finger tight after break in! Retorqued them to 35 lbs, no problems since.

Thu Aug 14, 2008 2:01 am

Whether or not you need to retorque has a lot to do with how well you torqued the heads to begin with.

First you need to rotate the engine 90 degrees so that the head comes straight down on the cylinders. Lightly torque the head to keep it in place, then rotate the engine 180 degrees. Install the 2nd head and lightly torque it. Then you can return the engine to it's normal position and alternating sides, sneak up on the torque a few foot pounds at a time until you reach the specified torque.

If you bolt the heads on the engine incorrectly in the normal position, the heads weigh down the studs so the studs are at a diagonal when you torque them. After a few heat cycles things will shift and the torque will relax a bit, which can result in a cylinder head leak, unless you retorque the cylinder heads. So in this case I'd say retorque the heads after 500 miles or so.

You also want all studs lubricated with the same lubricant so that the torque is even.

Then, and this is very important, retorque again in an hour, let it sit overnight and retorque again. You will find that the torque on the bolts may relax a bit.

It is also important to pull the torque wrench dead slow, otherwise your torque will be low.

But I don't see anything wrong with retorquing the heads if it will give you peace of mind.

Scott Novak

Thu Aug 14, 2008 2:32 am

The VW factory never retorqued the heads and it wasn't a required service.

Thu Aug 14, 2008 12:19 pm

lostinbaja wrote: The VW factory never retorqued the heads and it wasn't a required service.

Good news...all I needed to hear

Thu Aug 14, 2008 12:29 pm

dirty_73 wrote: lostinbaja wrote: The VW factory never retorqued the heads and it wasn't a required service.
Good news...all I needed to hear
You also need to hear that stock engines also had cylinder head leaks while under warranty.

Just because retorquing cylinder heads wasn't a factory recommendation, doesn't mean that it shouldn't have been done.

Scott Novak

Thu Aug 14, 2008 2:59 pm

Scott Novak wrote Quote: If you bolt the heads on the engine incorrectly in the normal position, the heads weigh down the studs so the studs are at a diagonal when you torque them.

This sounds like it makes sense, BUT...............

When I built my engine, the fit of the cylinders in the case and the fit of the head on the cylinders left my studs sort of "floating" in the holes in the head (I could wiggle them), in other words, little to no weight was pulling down my studs.

Maybe I got lucky?

Then again, I have quiet straight cuts and an EMPI merged exhaust that fits!