still2hi Posted October 31, 2003 Report Share Posted October 31, 2003 well heres the deal. i bought an 350 long block from a engine rebuilder and put it in and after about 300 miles it chewed up the crank bearing. talked to the company i got it from they told me to pull it out and they would look at it. it chewed the crank, the bearing was almost gone and the rod was bent. they replaced it all and told me the reason it happened was because the crab was to big. so i said ok and put it back in the car and now after another 200 miles its doing the same thing. heres what is on the eninge... 350 block bored .30 over and crank ground .10 under heads are 305 heads and cam is a 288. i have talked to some people about what causes this and i want to hear your opinions(sp) so i know as much as possible! thanks guys!! Quote Link to comment Share on other sites More sharing options...
Lustalbert Posted October 31, 2003 Report Share Posted October 31, 2003 how in the hell does a oversized carb do that? only concivable way i can think is that at wot it is going lean due to the carb not geting enough vacum signal to meter fuel, and causing detonation, but that dosent seem to me that it should do that on a fresh engine. i would also expect 1 or 2 other cylinders to have the problem as well. you may have gotten a bad cam, in wich case there should be a dent in the top of the piston from the valve. Perhaps a bad gasketleaking enough air to lean out that cylinder? (seems to me it would idle like shit) distributor arcing? perhaps that cylinder is getting spark at the same time as the cylinder before it? Quote Link to comment Share on other sites More sharing options...
SHIEF Posted October 31, 2003 Report Share Posted October 31, 2003 A carb would never cause that. I'd start checking clearances, and making sure those crank barrings are the right ones. Also check the crank journals and make sure theres nothing in them so oil can get to those barrings, or they might spin or seize up, this will cause your rods to bend or break. Quote Link to comment Share on other sites More sharing options...
still2hi Posted October 31, 2003 Author Report Share Posted October 31, 2003 well the first time they replaced the crank it was only one bearing and the crank was chewed up about 1/8''. im thinking that one of the oil passages is pluged and its not letting the oil flow through to it. i dont know. im waiting to hear what the company is going to do. the cam was a brand new cam and was broke into like it should have been. Quote Link to comment Share on other sites More sharing options...
Nick Posted October 31, 2003 Report Share Posted October 31, 2003 Which bearing? Theres 5 of them. Check into a thrust bearing problem, or even a bad dampner. If the motors not balanced properly, you'll have this problem every time. Quote Link to comment Share on other sites More sharing options...
rl Posted October 31, 2003 Report Share Posted October 31, 2003 Have you ever had the block line honed or at least checked for true? Nick, check your messages sucka. Quote Link to comment Share on other sites More sharing options...
nurkvinny Posted October 31, 2003 Report Share Posted October 31, 2003 Sounds like the machine shop is doing piss-poor work. Their work is bad or their parts are bad, either way, I'd find a new place to do business with. Especially after the "your crank failed due to too big of a carb" line. graemlins/wtf.gif This sounds like a joke of a shop; is it a large, well-known company? Quote Link to comment Share on other sites More sharing options...
SHIEF Posted October 31, 2003 Report Share Posted October 31, 2003 Sounds like you need to get some money back, then go through the motor. Something is very wrong and you just need to take the motor apart, then put it back together so you know it's right with new stuff. Quote Link to comment Share on other sites More sharing options...
still2hi Posted October 31, 2003 Author Report Share Posted October 31, 2003 i went to this shop about a month ago and asked if they had any blocks for sale. they said they had one from when a guy brought it in and never picked it up and they did all the work and just wanted there money back for the work they did. so no i have not checked the block to see if its true or been honed or anything. i figured since they are a engine rebuilder that they would have built the bottom have right so i did not check it when i got it. the first time it went bad i told them and they took it back and said they fixed the problem and that it was to big of a carb. i figured that time that they realized they messed up fixed there problem. (i think this b/c he never tried to make me pay for it and if it was due to a carb problem that they had no control over, then they would have made me pay). i think im going to tell them to take the block back and give me my money back and find a new one?? have to wait till monday to hear from them. thanks for your help and if anyone has anything else to say, then do so, so i can learn as much as possible!! Quote Link to comment Share on other sites More sharing options...
90gt Posted November 3, 2003 Report Share Posted November 3, 2003 Just curious where did you get that block from. I've had the same similar problem with mine and the same story about somebody never picking the block up. I picked it up a ERS and they sad everything was done and just wanted the money for machine work and the time they had in it I think the block is fucked because I lost oil pressure after 1000miles. Quote Link to comment Share on other sites More sharing options...
Guest White Horse Posted November 3, 2003 Report Share Posted November 3, 2003 Dude, sounds like shabby work/manufacture. +1 on plugged oil passages Also +1 on bearing size. Along the same lines, maybe the race is bad.(bad machining, out of round, worn/damaged..etc) Snowballs chance in hell did a carb cause that shit. (Crab.. hehehe) +100 on getting some money back + a new engine. Quote Link to comment Share on other sites More sharing options...
still2hi Posted November 3, 2003 Author Report Share Posted November 3, 2003 qwk90gt check your pm's. lol i never noticed that i said crab instead of carb Quote Link to comment Share on other sites More sharing options...
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