darrells3rdgen

I have a 1986 trans am with a rebuilt 350 4bbr and for a while I thought I had a bad starter so I replaced starter then the bolts and at last the flexplate, and I was still having problems with the starter moving on the mount pad just enough to cause it to not engage with the flywheel. with a good spotlight and a can of brake cleaner I found my problem it was the outer bolt hole was cracked in 2 places, I have to much money to ditch the block and start over.

Is there a way to repair the bolt holes?

pellmanm

iTrader: (1)

The block is cast, so it can't be welded properly. If the bolt hole is cracked, then nothing can be done to fix it.

ede

weld it, redrill, and retap. how bad or how big is the crack? you wouldn't want any weld in the area to redrill and tap unless it's Ni filler. steel filler will draw carbon from the casting into the weld and make it too hard to machine. wouldn't be real hard to fix.

Vader

Dang. Beat me to it.. I'd listen to ede. He's welded a piece of cast iron or two. Many of us have. I'd really hesitate to do it in place, however.

darrells3rdgen

the bolt hole thats cracked is the outer bolt hole, a friend suggested that I should install a stud and locktite ,

the engine is a 1969 block I had it bored, and completely rebuilt . I spent a total of $3,ooo. on parts, the labor was free because I helped him restore his 68 firebird.

I have been thinking of yanking the engine and mount it on my engine stand . and take some pictures, but the only problem with that is my car is a F body and its a real pain to get to the top bellhousing bolts. when we installed the 350 in the car I only could get 2 fingers on the bolts to get them started, and after severl attemps at that, and a few words I managed to get them in and im not looking forward to doing that again.

also my car had a factory 305 ho engine with a carb. the factory exhaust manifolds wont fit the 350 I installed. I would like to find a set of headers for the car but I dont know what will bolt up to the engine and still fit the car. any suggestions?

darrells3rdgen

the bolt holes from what I can tell are cracked about 1/2 inch from the mounting pad surface. noone around my town can weld cast iron, from what I have heard it's sort of a "lost art". I would be willing to pay a couple hundred bucks to get the block fixed, but only if it would hold under stress as the engine has higher compression than stock.
the engine has an estimate of 460 hp and about 400 ft lbs torq. and has a 1/8 mile pass of 11.34 seconds . as you can see why I dont want to scrap the engine bock.

ede

starter bolts are special made to index the starter i nthe correct location, i doubt a stud would work

darrells3rdgen

I was afraid it wouldnt work either, so I guess im going to pull the engine anyway and haul it around in the back of my pickup and hope someone can weld it and repair it.

I live in kentucky, what state do you live?
and what would you charge?

ede

it isn't rocket science, just about any semi skilled semi knowledgeable dumbass with a welder could do it

darrells3rdgen

here is a picture of the cracked and broken starter bolt hole.

Supervisor42

1/8th mile pass at 11.34?
Yep, that's a keeper!
(Dale Jarrett said he was gonna race the truck)

Vader

Oh, you have one of those blocks.

The photo looks like one of those blocks with "the other problem", as opposed to "the problem" that plagued so many other SBC castings.

I'd want to weld up that entire area, and deposit additional material outside the cast boss to bolster it further. Mill, file, and/or scrape the area flat so that you can mount the starter correctly.

Before you drill/tap the new hole, be absolutely certain that the starter is mounted straight, flat, and exactly perpendicular to the flywheel. Use a machinists' square to verify the mounting position after installing a NEW starter bolt in the inboard hole to hold the starter. The old bolts may be slightly worn, allowing misalignment. Anything other than a starter bolt will not have the correct shoulder size and knurling to prevent movement. You'll only get one shot at this. You don't want to repeat the factory's mistake.

"Lost art?" I'm probably the dumbass that ede is talking about, I guess. Welding castings is not very difficult. That used to be a required skill before someone could use the term "weldor". Just because it isn't easy or common doesn't mean it cannot be done. By that measure, a lot of things must be "lost arts".