So im ginally putting my block together (350 from a 88 k2500) got the crank in and when i got to the 4th main cap i snapped a bolt about a half inch down in the block.... so i need to know what replacement bolt i need to get and how im going to get that out. Any advice is greatly appreciated

 

One of the main cap bolts?

Drill, and easy out......

 

Well the way it broke its all messed up and not flat so i cant get the damn drill bit in the middle guess i gotta just keep trying. Now are all 2 bolt main 350 cap bolts the same?

 

You can try a punch to set the drill bit into, it's easier to hold in position and tap w/ a hammer. If the face is at an angle you can skew the punch and/or drill bit to keep the start of the hole in dead center. This is crucial imo.

That said, a half inch down would be difficult.

Don't use easy outs since they typically expand the bolt and lock it in place even more. Once you have a hole in the center keep using larger bits until you are very close to the threads. Oil is your friend.

Most important is to take your time and get that start hole dead center.

That's my

 

I guess im gonna keep trying. If it comes down to it i guess i could over thread it and put a heli coil in there right? Ive had to do that with a spark plug before

 

Focus on getting the hole exactly in the center. I'll try posting an example. Yes, it was flat but I've done uneven ones before. Never 1/2" into a hole though. Never used a heli coil.

 

My dad can probably show me how its done hes usually pretty damn good at these kinds of things

 

If the motor is out and in the shop just take it to a machine
shop and have the pros do it.
If you mess up the block/bearing races/web/etc. doing it yourself
its gonna get $pendy !

 

Id rather do it myself. I litteraly just got it back from the machine shop and i have my cam in and crank with most the caps on id hate to take it all back off. If i cant figure it out i guess thats just what ill have to do though

 

Either way if I had a drill bit anywhere NEAR an assembled motor, I'd be disassembling it to clean it again.

 

This is going to be a tough one, since it is 1/2 inch in the block. I have used a die grinder with a carbide bit to flatten out the broken bolt to help get the punch to center better.

 

Yea probably gonna pull it all out and spray it real good with an air hose

 

Might want to invest in a set of Left Handed Drill Bits. They drill in reverse and sometimes unscrew the bolt as you go in.. Harbor Frieght..

http://www.harborfreight.com/left-ha...-pc-61686.html

 

Might be a good investnet

 

Use the threaded hole that the broken piece of bolt is in to your advantage. You can punch the "exact" center of the broken piece prior to drilling it by using a transfer punch.


I've found that I use my set of transfer punches way more often than I ever imagined.

BTW, use the transfer punch to make a light, "starter" punch mark. Then use a proper center punch to make the starter punch deeper for drilling.

Good luck.

 

how did you snap off a main bolt? those things are 7/16" grade 8 or better and take a LOT of torque before they break...

once you get the bolt out, it might be time to find a different torque wrench..

 

I guess i shouldve got new bolts. Idk how it snapped. But new bolts are on the way and i got the old one out with a flathead some how haha

 

Good info. That's something I'll keep in mind.

Wow, you got lucky. I was going to mention something like that but didn't figure it would work.

 

Ok so i ordered new bolts and just gotthem today theyre about a 1/4 inch i got some from arp 134-5002 is the part number it says its for a sb chevy so i dont understand why theyd be different

 

I think that part number is for small journal blocks. Don't you need bolts for a large journal block?

 

Yea i just noticed that. I didnt know about the different journal sizes but i looked it up and i think i need medium journal.... so now i gotta exchange these for some medium ones haha.... well gotta learn things the hardway

 

Yep... 55-67 small journal, 68-up med. journal, chevy 400 small block large journal

 

So anyone know the part number to the arp medium journal bolts i cant find them

 

ARP P/N 134-5001. The 350cid and 400cid use the same main cap bolts.