Olds cam question

[jriggs]

i tore the 307 apart in the olds over 2 weeks ago, was going to do just intake and carb, come to find out the pushrods were 2 tight cause the lifter to break and caused a pushrod to have a worn spot in it, had the money and wanted to build an olds motor anyways, everyone else says im stupid but whatever... lol, went to advance to get a cam, the didnt show any at all for an olds 307, went to autozone, they had 56 different types, found one, odered it and they said it would be in within 2 days, went in on a saturday no show, said it would diff be there monday, went in monday no show, got pissed said i wanted my money back, refunded my money. i called summit they said it would take 22 days for the kit i wanted. I wanted cam, lifters and timing chain, so i went with the cam and lifters kit and a summit brand timing chain, came in within 2 days... oh and when i ordered the pushrods the ones i bought from AUTOZONE, was an inch 2 short, so the autozone in newport ky can go straight to hell....

 

[kustomkyle]

i tore the 307 apart in the olds over 2 weeks ago, was going to do just intake and carb, come to find out the pushrods were 2 tight cause the lifter to break and caused a pushrod to have a worn spot in it, had the money and wanted to build an olds motor anyways, everyone else says im stupid but whatever... lol, went to advance to get a cam, the didnt show any at all for an olds 307, went to autozone, they had 56 different types, found one, odered it and they said it would be in within 2 days, went in on a saturday no show, said it would diff be there monday, went in monday no show, got pissed said i wanted my money back, refunded my money. i called summit they said it would take 22 days for the kit i wanted. I wanted cam, lifters and timing chain, so i went with the cam and lifters kit and a summit brand timing chain, came in within 2 days... oh and when i ordered the pushrods the ones i bought from AUTOZONE, was an inch 2 short, so the autozone in newport ky can go straight to hell....

Is yours a roller cam/lifter engine? Also, which brand of cam did you get from Summit, and the specs? They have a few from various manufacturers that are close to the VIN 9 factory specs, but I have no idea what they really mean.

 

[DrRansom442]

differences between a VIN 9 and VIN Y 307 are hardly night and day ... I believe the VIN 9 was a mere 20 hp gain over the standard 307. My 86 was a Salon so it did not have the H.O. 307 ... had the 200-4r and 2.41:1 gears ... I forsee no issues whatso ever with a VIN 9 backed by 2.56:1 gears aside from you'd probably be happier with something in the 3.42:1 range. I doubt the gas mileage will be THAT noticable, but acceleration probably would be.

 

[joe_padavano]

differences between a VIN 9 and VIN Y 307 are hardly night and day ... I believe the VIN 9 was a mere 20 hp gain over the standard 307.

Actually, VIN Y motors had an (optimistic) 140 HP vs. 180 for the VIN 9.

 

[kustomkyle]

Do you think the roller 307's respond well to headers and (true) dual exhaust? One thing I am concerned about is the A.I.R. tubes. Can you keep them with headers? I have a set of Blackjack headers I wanted to install after the rebuild to open up the exhaust as much as possible.

Also, would a .030 overbore make a difference in power? I'm not sure if the engine needs to be bored that much, it does have 92,000 miles and has 2 cylinders that fowl out the plugs (it runs with those "anti-fowler" spacers). The oil gets pretty black and watery by about 2,000 miles.

I know it would be much easier to get decent power out of a 350 Chevrolet or Olds, but I like the economy of the 307, and want to keep the original engine with the car.

 

[DrRansom442]

Do you think the roller 307's respond well to headers and (true) dual exhaust? One thing I am concerned about is the A.I.R. tubes. Can you keep them with headers? I have a set of Blackjack headers I wanted to install after the rebuild to open up the exhaust as much as possible.

Also, would a .030 overbore make a difference in power? I'm not sure if the engine needs to be bored that much, it does have 92,000 miles and has 2 cylinders that fowl out the plugs (it runs with those "anti-fowler" spacers). The oil gets pretty black and watery by about 2,000 miles.

I know it would be much easier to get decent power out of a 350 Chevrolet or Olds, but I like the economy of the 307, and want to keep the original engine with the car.

retaining AIR tubes should NOT be an issue ... since they screw into the heads of an Olds unlike some brands that they screw into the exhaust manifolds. Your issue will be more along the lines of needing to weld a bung into a header for the O2 sensor ... still not hard and bung kits are availible. Also you will probably want to strap a heat riser onto the driver's side header - since you won't reuse the factory one when you lose the manifolds. You MAY run into some interesting "mounting" issues as there are studs in the factory manifolds for mounting things like the diverter valve and those studs may or may not clear the header tubes (I am not sure all my emmissions went bye-bye - my car is now emmissions exempt due to age). Since you mentioned retaining AIR tubes ... I must assume you live in an area that does smog testing. Check with the local authorities to see if and how exhaust mods are legal. Here, you are not allowed to modify "Y-pipes" and delete converters ... you may have to restrict your exhaust mods till "catback" like a 442. I'd also not go too wild with the exhaust ... those 307s seem to like some backpressure. A .030" overbore is pretty standard in most overhauls and a little more displacement sure won't negatively effect power ... how much you actually gain ... you probably won't even be able to feel it.

and yeah others will tell you "just drop a Chevy in there" ... IMHO, they don't belong - you bought an Olds after all - not a Monte Carlo. Sure GM put some 305s in the Cutlass but I reguard that largely as a mistake on their behalf.

 

[kustomkyle]

Thanks for all the information. I was concerned with the A.I.R tubes because Delaware checks emissions on everything from 1975 unless you have it registered as a classic, which limits the mileage it can be driven. I wasn't sure how they were mounted, at first I thought they were on the heads, but then I saw a topic about "headers with A.I.R tubes" here, and got confused. I guess Chevrolet engines have them on the exhaust manifolds.

I don't believe they have anything against modifying the y-pipe since they don't look under the car. They just have a sniffer. I'll have to check and make sure though.

 

[DrRansom442]

Thanks for all the information. I was concerned with the A.I.R tubes because Delaware checks emissions on everything from 1975 unless you have it registered as a classic, which limits the mileage it can be driven. I wasn't sure how they were mounted, at first I thought they were on the heads, but then I saw a topic about "headers with A.I.R tubes" here, and got confused. I guess Chevrolet engines have them on the exhaust manifolds.

I don't believe they have anything against modifying the y-pipe since they don't look under the car. They just have a sniffer. I'll have to check and make sure though.

Yes definately be sure first ... and yes Chubbies have the AIR tube in the manifold ... emmissions aps with headers are easily fixed with a drill.

 

[jriggs]

seems like i should have did some home work first. i listened to a good friend of mine that knows his sh*t. He gave me his honest opinion and i went with a comp cam. The intake specs are .475 and the exhaust specs are .480. Does anyone think im gonna have a problem with this cam. I got it all back together and wishing i didnt touch the damn thing to begin with. I put on a 600 holley and elderbrock intake manifold with new pushrods. I dont know sh*t about 307's all info would be greatly appreciated. I should have asked all this before i did the work but got in a hurry and its done and to much money was invested.

Please Help........

 

[dan2286]

seems like i should have did some home work first. i listened to a good friend of mine that knows his sh*t. He gave me his honest opinion and i went with a comp cam. The intake specs are .475 and the exhaust specs are .480. Does anyone think im gonna have a problem with this cam. I got it all back together and wishing i didnt touch the damn thing to begin with. I put on a 600 holley and elderbrock intake manifold with new pushrods. I dont know sh*t about 307's all info would be greatly appreciated. I should have asked all this before i did the work but got in a hurry and its done and to much money was invested.

Please Help........

Are you having problems with it running or something??