Engine Block Cracked

[64GunPilot]

Has anyone ever tried brazing? I am thinking to open up the cracks with a dremel, and then braze with Muggyweld SSF-6 brazing rods specifically for cast iron using a torch. Maybe I can preheat the assembled engine from the side using a propane IR heater so there wouldnt be any shock heating/cooling.

I just need to seal up the cracks, not to concerned about structural rigidity. I been back from Iraq since July, its time to start getting the car back into shape. Would like to make the ECR in December for HPDE. Will be the first time driving on 17" RR's (thanks Michael Mosty for the donation). Maybe comp school early next year to join you guys for the 2021 season.

[Fbody383]

Where is the crack?

I did some quick google about welding/brazing/soldering. I've done some copper pipe, but not much. Heat up the spot enough to melt the brazing rod and let it draw... Are you worried the fix will break it more... if it's not usable, clean it up, braze it and send it.

ECR is slick from the dust so a little water might improve some places.

[Gerno]

I think it would be just as easy to find a 305 block and have it bored/honed to your piston size and swap the internals over. Have you ever assembled an engine in the past?

[Gerno]

This is in Waco. I'd just grab it and throw your TPI/accy's on it and see what happens, can't be worse than a cracked block and I bet you can get it much less than asking price. At least then you're on track and getting some practice in.

https://www.facebook.com/marketplace...75025250081624

[64GunPilot]

This is in Waco. I'd just grab it and throw your TPI/accy's on it and see what happens, can't be worse than a cracked block and I bet you can get it much less than asking price. At least then you're on track and getting some practice in.

https://www.facebook.com/marketplace...75025250081624

Yea, Sean has a good 305 as well I’ve considered buying. This engine I have runs amazing and was super reliable. Just had a water jacket freeze damage. Ran it for a whole season with JBWeld gooped over the cracks with almost zero preparation (trackside repair). If I can just seal up this block I feel she’ll last for a good long time.

[fscott]

Has anyone ever tried brazing? I am thinking to open up the cracks with a dremel, and then braze with Muggyweld SSF-6 brazing rods specifically for cast iron using a torch. Maybe I can preheat the assembled engine from the side using a propane IR heater so there wouldnt be any shock heating/cooling.

I've TIG welded cast iron once, using specialty rods. I got away without preheating. The trick there was to put down some weld, and then immediately grab a hammer and punch and start beating on the weld bead as it cools. Then repeat as needed until done.

When you weld cast iron, the weld shrinks enough to pull away from the base metal, which is why you normally preheat the entire workpiece. But by peening the metal as it cools, you're forcing it into the gap that's trying to open.

I agree with others, a new block is probably better. But I thought you might want to know this trick in case it ever comes up.

[64GunPilot]

LM7 5.3 Engine, intake manifold, throttle body, injectors, exhaust manifolds, and T56 transmission all bought and paid for. Still needing a lot of other stuff, the $$$ is starting to add up and Im starting to think maybe I would have been better to just do a new 305 shortblock. I enjoyed being slow with the 305 TPI, at least I had an excuse. But after an LS swap I wont have any excuses. I'll just be slow and broke LOL.

[Supercharged111]

Still gotta do the oil pan, accessories, cheater short 5th, and electronics. It's all on my white board and it makes me throw up in my mouth. After Hallett I seriously question if it's worth it.

[64GunPilot]

There was a lot of information in this thread. I appreciate all the help from everyone. Declaring LT1 / T56 swap complete. Today I got the car dyno'd. It runs and sounds good. Gonna register with Chin for a trackday at MSR-H next weekend (Dec 17th) for my own test n tune, and a little practice there before next season opener.

I ended up taking 30 days of leave and have spent hundreds of hours working on this thing. 12-16hrs a day sometimes. It was WAY more work and way more odds 'n' ends that eat at the overall budget of the conversion than I ever thought about. I got it done realistically for about $2500. Some may balk at the LT route I went instead of LS, but I think the LT was cheaper overall and it kinda fell into my hands cheaply and easily.

Again thanks for the advice from everyone. Special thanks to Dustin for lots of back and forth LT1 questions, and Morgan for giving me some free aluminum LT1 heads. I hope if nothing else to add to the car count next year.

20221207_055845637_iOS.jpg

[michaelmosty]

Wow, that looks super clean, nice work Dylan!!!
I hope the test day goes great next weekend and look forward to having you back on track next season!