Mating case halves

[Advokat]

Bought a set of new case hardware for my present rebuild. It came with six large nuts (15mm I think) for the six large studs that hold the case halves together. These new nuts are the nyloc type nuts that cannot vibrate themselves free. I noticed, however, that this kit did not come with new washers for these studs.

1. Do these nyloc nuts get used without the washers and that's why they weren't included?

2. Will it hurt for me to use the old washers along with the nylocs?

3. What is the correct torque to be used with these nylocs?

Engine is based upon a 1600 d/p w/8mm studs and case savers.

Thanks

[This message has been edited by Advokat (edited 07-22-2002).]

[joe of centorg]

Use the stock washers! I use the stock nuts too, and have never had a problem.
If you must use the nylock style, get a torque wrench that is very sensitive (inch lbs.).
The stock nuts spin on with your fingers, but the nylocks are TIGHT. So see if you can measure the average force required to simply spin these things.
Add this to the stock torque recomendations 22lbs.
Good day hoser eh, Joe

[RT]

Plastic end of the nylocks out, away from the case. Use the washers. Torque these up to 28 ft lbs in three steps, using this pattern; center up, center down, left up, right down, left down, right up. Check for easy rotation after each step. Then torque the small hardware, and check the rotation again.

[Marc]

Are they Nylocks or seal nuts? Probably Nylocks if they came in an aftermarket hardware kit. I prefer to use Type I seal nuts (19mm wrench size) which are designed to be installed with the seal ring against the case without a washer at 18 lb-ft. The seal ring is usually red, sometimes blue. Some builders(including Berg) recommend putting them on with a washer, with the seal ring out - like a Type IV engine is from the factory - and torquing them to 29-30 lb-ft(or even more). Unlike Nylocks you don't need to be concerned about seal nuts giving you a false torque reading.
If you're using a line-bored case you might want to ask the machinist what he torqued the case together at for line-boring (26 seems to be pretty typical) and stay close to that for a final torque. I don't know of anyone who follows that factory spec of 18; 22-25 is commonly used.
Confused enough yet? This is one of "those" areas where almost everyone you ask has a different answer. The good news is that they all seem to work.

[Advokat]

Thanks for the replies guys.

[type IV mainframe]

I personally use the stock hardware on those areas. I've had the nuts strip out on me on 2 of the six nuts. I probably just got some low quality nuts. I got one of those kits too. I also like the ease of putting them finger tight till tightening and torquing begin.

Just my two cents.