3.2 Rod Bolt Help

[1972_911T]

I have just attached my rods back onto my crank using new std rod bolts I followed Waynes the book to the letter on tightening the bolts however some of the bolts have less thread through the nut than others which is making me a little paranoid especially with all the horror stories of rod bolt failures on 3.2's am I just been paranoid or does this indicate a problem?

Steve

[ChrisBennet]

Post pictures.
-Chris

[1972_911T]

Im not sure this picture show it very well it is only a small amount im not sure if im just been paranoid but the bolt on the left definatly looks to me to have more thread through it than the one on the right are all the bolts the same size to start with or is there some variation?

Think I may just bite the bullet and swap them for ARP's

[ChrisBennet]

Put some calipers on the bolts and you'll be able to tell pretty quickly if they are the same size or not. (Digital calipers are only like $40 and you'll use them for years.)
I would look that the other side of the bolt and see if they are seated on the rod or if they are rotated so they are riding up on the side and are caught on the side of the rod.
-Chris

[1972_911T]

I already chked to see if there seated right all look fine I measured them with the digital calipers and there is a slight difference but from reading the arp installation instructions it tells you to measure the bolt first the work out how much it streaches this made me think that all bolts may not be exactly the same size to start with, wished id measured them before they were fitted.

[ChrisBennet]

This is from some ARP's I did a while back. The shortest was 2.7398" and the longest was 2.7543" or a spread of .0145"
I don't know how variable the stock bolts are in size.


-Chris

[1972_911T]

are the ARP's reusable like the raceware or single use?

[ChrisBennet]

ARP's are reusable.
-Chris

[1972_911T]

Ok I just measured them the two extrems are on that rod shown in my picture which range from 2.7355 to 2.7380 all the rest fall within this range does this range sound ok?

Even if these are ok im still tempted to go for the ARP however I dont just want to waste money this engine is purley a street car and will never see a track while I own it are ARP's or the like that nesessary?

Steve

[ChrisBennet]

For your own street-only motor, ARP's aren't necessary IMO. When I do a motor with 9mm rod bolts for someone I use ARP just 'cause I need to cover my behind so to speak.
-Chris

[1972_911T]

If I seal my case halfs back together and then decide I want to swap my bolts for ARP's (probably on pay day) is it possible to do while the case halfs are together im sure I have read somewhere that it can be done, is this correct?

Steve

[Rot 911]

Originally posted by 1972_911T
If I seal my case halfs back together and then decide I want to swap my bolts for ARP's (probably on pay day) is it possible to do while the case halfs are together im sure I have read somewhere that it can be done, is this correct?
Steve

Yes, but it isn't as easy as some people make it out to be.

[WydRyd]

Sorry, but why don't you just bite the bullet and install quality ARP Fasteners? You'll have peace of mind and not have to worry about the common rod bolt failure issues in the 3.2's. Whilst you're at it, install ARP head studs too.

Might as well address all the weak components during the rebuild once and for all. That includes the valve guides too.

Just my 2c worth

[1972_911T]

Ok ive decided im going to go for the uprated bolts is there much difference between the ARP or the Raceware?

[snowman]

Your stock bolts are fine. UNless your going to actually race it, for get obout it. Porsche rod bolts are very good and if you keep it wihtin the factory limits on rpms you will be ok.

For Racing I do not think ARP or Raceware are good enough. For real racing I would only use Carillo Rods with SPC rod bolts.

That leaves ARP and Raceware for inbetween apps. Better than street but not good nuff for full racing.

TO clarify things for you, if you do not put enough bucks into the entire engine for racing, ie big bucks, do not race it. How much. Well if you have to ask....

If you are a real avid tracker, and plan to track the car a dozen times a year or more, definately do the arp or raceware bolts and a bunch of other things you have not mentioned, half way to big bucks. But if you track it for only a half dozen times a year, go stock.

How to know if you are really racing??? Your on your third wife and are on the verge of divorce, Your wallets empty.

Are you an avid tracker? Your divorced and your wallets nearly empty.

PS your numbers seem reasonable for anything stock.

[Wayne 962]

Originally posted by ChrisBennet
For your own street-only motor, ARP's aren't necessary IMO. When I do a motor with 9mm rod bolts for someone I use ARP just 'cause I need to cover my behind so to speak.
-Chris

I disagree completely. I have seen many stock motors with rods sticking out of the sides of the cases because of these stock rod bolts. Throw them away and don't use them. I should refuse to sell them, in fact...

-Wayne

[1972_911T]

I agree wayne you shoud stop selling them, I initially decided after reading you book that recommends that there changed that if your still selling them they carnt be all that bad! After installing them I have now thought better of it and ordered the ARP's

[1972_911T]

Ok I now have my ARP bolts the instuctions tell you how to install them using two methods the first is to torque the bolt to 35ft lb then un tighten and repeat 2 times. It then goes on to say that they recommend using the stretch method to a stretch of between 0.0117 and 0.0122 but it doesnt give any information on this procedure. I have installed two of my bolts and toqued them the 35lb as it recommends and then measured the bolts they have only stretched 0.0085in. Do I just keep tightening them untill they reach the spesified stretch?

Steve

[RoninLB]

I had to use over 75# to get raceware rod bolts to stretch to spec on my 2.7

[snowman]

Yes. If you can do it use the stretch method. Much more accurate and will give you all the bolts have to offer.