trying to find thread stretch gage use without splitting case

hcoles · 05-21-2008, 07:18 PM

We are considering ARP rod bolts on a 3.2 but don't want to (too afraid to?) split the case.. seems smart to use the stretch measurement method compared to the multi torque or torque to angle method. I saw on one thread it was mentioned there was a thread on here with how to use stretch gage without splitting the case. The motor owner is running a 6800rpm red line SW chip... so thinking improving the rod bolts is not a bad idea... engine has 160k miles and lots of track miles. I know we are crazy to not split the case. I read a number of the pros/cons to replacing/upgrading the rod bolts or not... I could go either way... maybe better to leave well enough alone.

Thanks.

JohnJL · 05-21-2008, 07:47 PM

If you have the engine that far apart you might as well split the case. It will make assembly much easier, not to mention inspection and cleaning. The only real additional cost is a set of bearings, a tablespoon of 454 and a few o rings. You might actually save some time.

hcoles · 05-21-2008, 08:19 PM

there just seems like so much to clean and so many bolts/etc. - but I know splitting is the correct thing to do... I'm helping a friend with his engine, I just did the top end on my car..but it had very low miles...

JohnJL · 05-22-2008, 04:30 AM

Always do the correct thing...

hcoles · 05-22-2008, 07:06 AM

Quote:

Originally Posted by JohnJL

Always do the correct thing...

you're killin me

304065 · 05-22-2008, 07:10 AM

Just follow ARP's instructions for using the torque method-- burnish threads 3x and use their lubricant and you will be fine.

There is no room to get the stretch gage inside the case and hold it there reliably, even if you modified it to use a smaller dial indicator you still couldn't read it. Sure there are gaging transducers made by Mahr-Federal and others that could be used inside, but you don't want to spend $10K on metrology equipment to save four hours of work.

hcoles · 05-22-2008, 08:12 AM

John,
thanks... I think that's about what we were looking for... APR design is such that the 3x method will work. Stretch gage is better but good enough is ... good enough
-Henry

hcoles · 05-22-2008, 08:31 AM

update.. I'm making some progress on getting owner to split the case... I'll have to search and see what needs checking/replacing in there and how to reseal without leaks...

dtw · 05-22-2008, 09:03 AM

I keep meaning to post some photos of the intermediate shaft bearings I pulled out of the last engine I tore down. Completely WTFO - from a 100k, extremely healthy 3.0 engine. Have not seen a 'good' set of layshaft bearings come out of one since I can remember.

Get in there, check the oil pump, clean the case, measure the crank & rods, clean the case, replace all bearings, clean the case, replace intermediate shaft sprockets, clean the case some more, inspect intermediate shaft gears, clean the case again. Seal it up. Minimal additional $$

JohnJL · 05-22-2008, 01:57 PM

Sorry Henry, I wasnt meaning to be holier-than-thou. I'd hate to have you put everything all back together and have a problem later, or have to re-do it.

hcoles · 05-22-2008, 02:04 PM

no problem... I'm working on Tom to go ahead and split the case.. my only reservation is his ability to keep the area clean and organized... the feeling is if the case is split then we got more piles of parts all around the garage.. I told him he needs to get about 3 levels up on the anal retentive scale.. we'll see. One lever we may have is... he thinks he is going to replace the chains and cam sprockets.. if we can convince him to not run on the old layshaft sprocket with new chains.. then we may have a "lever". Of course I was too chicken to split my case 3 years ago or whenever it was... I was a 911 engine newbie at that point...now I know just enough to do something stupid.

jimbauman · 05-23-2008, 04:53 PM

I know Tom too - and the only reason Henry wants Tom to split the case is so he (Henry) can play.. :-) Actually, Tom is putting in 98mm Ps and Cs to replace the stock alusils, and for that reason, and no other really, the discussion came up about replacing rod bolts. My opinion is to leave well enough alone.... unless there is a compelling reason to replace those bolts, then yeah, do it right.

JB

Eagledriver · 05-23-2008, 06:11 PM

I'll throw in a vote for not splitting the case. You are replacing the rod bolts and can inspect or replace the rod bearings. The only thing you will not be looking at are the intermediate shaft and main bearings. Yes the intermediate shaft bearings are always showing copper but so what? They probably look like that after 1000 miles. If the rod bearings look good then you can assume the mains are good as well. Save yourself some money and lots of time and the potential of doing something wrong by not splitting the case. If you find a bad rod bearing then by all means split the case otherwise I don't see a down side.

-Andy