Chevy 307 knock and squeal, any ideas?

[Mettie5793]

Double camel humps are pretty old school but they will wake you up since you thought the 307 was nice. 350 sbc different Beast than a 307. More hp an tq for sure.

Yea it was fun while it lasted, but in the back of my mind I was always thinking about what a 350 would be like lol

 

[bob64]

307 was fun back in the day, but 350 is so common in G-bodies, must be a reason!! I only run BBC so l can't answer the why, 😁

 

[Mettie5793]

307 was fun back in the day, but 350 is so common in G-bodies, must be a reason!! I only run BBC so l can't answer the why, 😁

That sounds awesome but I think that's a little out of my experience level right now.

 

[bob64]

Well honestly it's about availability, 350 parts are everywhere an cheap an you can build alot of HP cheaply.

An building a BBC is the same as SBC just cost more.

 

[Ribbedroof]

Was everything toast after that, or were you able to save anything? My valves dont have the umbrella seals just the o-ring, would it be possible for the o-ring to shred like that and junk stuff up?

All we saved was the external stuff, as I had another fresh 302 ready to go into it (well, actually it was for my car, so he got the one that was in mine) before the drama. The externals were pretty specific to that chassis, so we reused those, along with the intake and carb.

I have seen nylon chunks from that era timing chain gears get into the oil pump pickup, so if they got ground up or crumbled into small enough pieces, they might get past the screen on the pickup like the stem seal pieces did.

In my younger days, nobody wanted 307s, they were the 267/305 of their time. Personally, I would look for something else. Locally, they want almost as much for a .060 over rebuld 350 as you can buy the GM universal crate engine for, so that might be something to look at.

 

[lilbowtie]

I got a decent set of camel humps that came with the 307, would those be enough for a 350 if I got just a short block?

Depends on which ones you have, Yes they are descend heads and will bump your compression and HP. What are the casting numbers - are they 194 or 202 - the biggy is if they have the accessory holes in the front. Will be very curious as to what your problem is - defiantly not good and at crankshaft speed.

 

[TURNA]

BAH thats just a header gasket leak!!


Is there oil in the engine???

Oil should have been squirting all over the place with the covers off.

I didn't notice any.

 

[DRIVEN]

I'll just repeat what all these other guys have said because I live to type. 307s were fine but never originally intended for performance use. I've had a couple and they ran good, just not hard. They were the predecessor to the 305, another fine engine that was just never intended for high performance (even with a 5.0 H.O. badge).
It doesn't much matter at this point what killed the 307 because it'll be much cheaper to replace it with a 350. An early one would be the easiest because literally everything from your 307 is transferable. If I were in your shoes I'd probably spend just a little more for a Vortec to get the good heads, higher compression, and roller cam. You'll need the Vortec specific intake though, which ads a little cost to the swap. Also, you'll need an electric fuel pump and later style flexplate. Everything else should be direct swap.
Good luck moving forward. Keep us posted.

 

[Mettie5793]

BAH thats just a header gasket leak!!


Is there oil in the engine???

Oil should have been squirting all over the place with the covers off.

I didn't notice any.

I thought it was kinda weird that it wasnt making a mess like when I set the valves but yes there is oil in it, it was just barely dribbling out of the push rods

 

[lilbowtie]

Be nice to know oil pr.