brand new timing chain loose, OLDS 307

[shotgun]

'Talked to my machine guy who did the crank and rods, said that its common on olds and pontiac motors for the chain to be loose.'

Can't speak for Olds, although others have, this is wrong for Pontiac also. Sound like a shoddy shop.

You can get .005 under timing chain sets for Pontiac to compensate for wear and/or align bore.

A align bore matches all the bores up, you can't assume it centers off the front hole. A shorter chain could be needed.

I bought a "little Old man" LeMans that motor siezed right after I bought it. Turn out in it's pass the timing set lost a few nylon teeth. It appeared that the set had been replaced but the pan was never cleaned out, dam flat-rate techs.

Anyway, my buddy stops over and I am eager to show off my baby so I crank her up. About 15 seconds in, death noises.

Pulled the pan, found nylon all up in the pickup screen. The screen was totally sucked up and pulled away alittle at the edge. A tiny peice of nylon had gotten threw, wedged in the oil pump gears, locking the pump. It stopped so abruptly that it sheared the tang off the pump drive from the distributor. So much for my "new" car. 😳

 

[shotgun]

Remember I don't speak Olds , so I don't know what innerchanges with what , but Dick Miller sells chain sets that are .005 , .010 and .015 under.

.005 removes about 1/2" of play on a Pontiac.

 

[CutlassGT]

Since I currently have my timing cover off for a chain replacement as well, I just walked out to the shop and measured the play on my new timing chain. With the chain tight on the left, I've got approximately 1/4" of slack on the right. The slack in the chain worried me as well. When mine started acting up, I knew it had jumped timing. Now, the new chain has almost as much slack as the original Olds chain, and there was only one tooth missing. Now I wonder if that really was the problem, and what awaits me upon restarting. Hopefully not the same rough running problems.

 

[olds307 and 403]

I put a stock Melling and Cloyes street roller on my 403. I then put the stock Melling on my 350, no problems. Maybe overseas junk?

 

[CutlassGT]

I put a stock Melling and Cloyes street roller on my 403. I then put the stock Melling on my 350, no problems. Maybe overseas junk?

Old stock (Not GM) USA made timing chain from a local parts house going out of business. Who knows? I guess I will in a week or two.

 

[Oldstech]

J
PS i should have listened to myself and put a 350 or 403 in it, all this agg for a 307. granted i know its a collector car and keeping the original motor is nice, but the time and money ive put into rebuilding this 180 horse dream motor :? makes me wonder haha.

Im really not meaning this to piss you off. But that 180 hp is at the flexplate. Its more like 130ish hp at the wheel. My 307 with all bolt on mods and a cam, chassis dyno at 166hp and 218 ft lbs. Its not a bad thing. But it seem that other peeps on this site think theses 307 are closer to 200hp then they really are. But I would keep the 307 in it too if I had a 442...well depending on the condition of the 442...hehehe

 

[Joeyg329]

i know its at the flexplate bub, i know its not at the wheels.SAE net rating 180 Hp, like you said about 130 at the wheel if im lucky.Bottom line its a pissy 16 second slug. Nothing like my monte ss (that i just had to sell, )I just meant that i went through alot of troubles for a stocker 307. My normal instinct is to remove engine and built a performance engine. This is the first G-body i ever rebuilt/left the stock motor in.