This isnt really a tool related topic, but I didnt know where to put it. I know someone will be able to answer this question for me. I had a 302 engine built for me a while back. It was assembled with a main girdle. Some plans for the engine have changed and I need to use a factory oil pan so the main girdle must go. I removed the main bolts (ARP) and girdle. I have new ARP main bolts to install. Now my question is will I need to recheck bearing clearance first or can I just install the new bolts and torque to spec?
Any engine builders here?
- Thread starter chavist93
- Start date
timgr
Well-known member
I'm not a pro, but I'd think you could just Plastigage it if it does not involve any new machining. I presume you are not changing the mains caps, and that the girdle went on top of the caps?
Merkava_4
Banned
Exactly! The main caps are not changing; so the clearances aren't going to change. Your crankshaft won't have the support it needs without the girdle for high RPM use ; so you'll have to keep your RPMs below 3000.
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Thats exactly what I thought. The girdle sits on top of the main caps. The main caps dont even have to come off. At least I didnt want to have to take them off. Even if the torque value on the main caps change a few ft/lbs the bearing clearance would still be the same correct?
Merkava_4
Banned
Do the main cap bolts hold the girdle on?
Yes, it sat on top of the main caps and the bolts went through the girdle down into the main caps.
chevy302dz
Well-known member
You should be able to just remove the girdle and retorque the caps with the new bolts. After you retorque the bolts check to be sure that the assembly spins free and if in doubt use plasticgage.
MajorPayne
Active member
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- Feb 27, 2008
- Messages
- 37
the caps typically wont come off even if you take the bolts out...so nothing should change
unless you hit one of the caps and it pops loose, they should stay put
just take the bolts out, remove the girdle, and replace bolts and torque them down
(this is assuming the engine is upside down on a stand, it is right?)
if its still in the car, then i suppose the caps will come out with the weight of the crank
in this case, i personally would plastigage them, but you can probably get away without doing so, the clearances are very unlikely to change
unless you hit one of the caps and it pops loose, they should stay put
just take the bolts out, remove the girdle, and replace bolts and torque them down
(this is assuming the engine is upside down on a stand, it is right?)
if its still in the car, then i suppose the caps will come out with the weight of the crank
in this case, i personally would plastigage them, but you can probably get away without doing so, the clearances are very unlikely to change
Yes, the engine is on the stand upside down. It has never been ran since the rebuild and the main caps didnt budge when i took the girdle off.
Now, is there a sequence to follow when torquing down the main caps? Ths is a 302 Ford by the way. Oh, and I appreciat all you guys help. This is the car the motor is goin in.
Now, is there a sequence to follow when torquing down the main caps? Ths is a 302 Ford by the way. Oh, and I appreciat all you guys help. This is the car the motor is goin in.
Merkava_4
Banned
Code:
5 1 3 7
6 2 4 8Basically like that with 3 passes; first pass 1/3 the final torque; second pass 2/3 final torque; and last pass 3/3 final torque.
You might need shorter bolts since you're not going through the girdle anymore.
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Merkava_4
Banned
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ToolmanTom
Well-known member
easy to remember on torquing assembly's, start in the middle and do a circular motion outward, and torque them to specs usually half torque or 35 ft lbs, then second round full torque. newer motors or special ones will use degrees after torque. main bearing cap bolt should be 60-70 ft lbs final torque.
nissan_crawler
Well-known member
Call me ****, but plasti-gauge seems damn cheap compared to a new crank and block. *shrug*
ToolmanTom
Well-known member
Yes it is good insurance, and also to put some fresh oil on the crank bearings. it has been sitting for a while.
MajorPayne
Active member
- Joined
- Feb 27, 2008
- Messages
- 37
yep, just torque it like merkava4 said and you should be good 
Was the clearance checked in the past?
If the caps don't come off, I don't see what you are expecting might change from releasing the torque and putting on new bolts.
I mean if you use plastic gauge again, you release the torque, remove the cap and put in the stuff, then put the cap back on, set the torque to some level then release, take the cap back off and measure the plastic gauge. Why would it change from one release and application of torque to the next if it didn't have a chance of changing again from being measured?
If the caps don't come off, I don't see what you are expecting might change from releasing the torque and putting on new bolts.
I mean if you use plastic gauge again, you release the torque, remove the cap and put in the stuff, then put the cap back on, set the torque to some level then release, take the cap back off and measure the plastic gauge. Why would it change from one release and application of torque to the next if it didn't have a chance of changing again from being measured?
I wouldnt say worthless. It will hold the halves of the block together when it splits and keep your crank from falling to the ground.
I went ahead and used plastigage anyways and it all checked out at .002. I dont think I really needed to, but at least I wont worry about it now.