H.O. Swirl Port Oldsmobile 307 parts?

[kustomkyle]

A couple more questions. Are the VIN 9 aluminum intake manifolds the same between what was on 442's and other cars like Cadillac Broughams?

Also, does anyone know how the gas mileage compares between a roller-cammed swirl port 307 and a 85'- H.O. engine?

 

[88hurstolds]

Yes, the intakes are the same from the Cadillacs. Inactuallity the VIN Y and VIN 9 86-87 intakes are all the same.

Also, to be correct with the carb you would need a 17086009, not the 17084553 which is for 5A headed motors.

You can turn your 86-87 307 into a VIN 9 by installing a balancer from any 350 motor (that is what they used) and changing the cam and the valve springs, thats it.

The 7A headed motors run almost like fuel injection and are wayyy better than 5A motors from the factory, in fact the best built GM V8 for fuel economy and performance was the 85-90 307. That is why they put them in numerous Cadillacs and station wagons. Don't be fooled by the port size, torque is where it's at. HP is over rated and means nothing if it isn't backed by torque to move the weight. The later 307's were given a bad wrap by the port sizes and people who assume they understand the technology but they out perform the H/O's bar none, that is why they got 8.5" rear ends due to the torque output (which is rather rediculous). The swirl port technology makes for a more complete burn which increases the torque output.

If you were to go with a 5A swap you might as well just install a 350 with all the work you have to do for just 10hp increase. And by the way, 10hp ain't much and the 7A headed motor has more torque than a 5A headed motor and at lower RPM (which is not saying much either) but makes for better drivability and fun around the town performance with better fuel economy:

VIN 9 83-85
180 hp@4000 rpm
245 ft-lbs@3200 rpm

VIN 9 86-90
170 hp @ 4000 rpm
250 ft-lbs @ 2600 rpm

 

[88hurstolds]

EPA states the fuel economy for an 87 Supreme is 16/23 and for an 85 is 15/22. No specifics are given on VIN 9 or Y but do state that it is a 307 with a 4 speed transmission.

 

[Blake442]

When I still had the 307 in my 442 it averaged about 17 city and 22 hwy if I kept my foot out of it.

 

[kustomkyle]

Yes, the intakes are the same from the Cadillacs. Inactuallity the VIN Y and VIN 9 86-87 intakes are all the same.

Also, to be correct with the carb you would need a 17086009, not the 17084553 which is for 5A headed motors.

You can turn your 86-87 307 into a VIN 9 by installing a balancer from any 350 motor (that is what they used) and changing the cam and the valve springs, thats it.

The 7A headed motors run almost like fuel injection and are wayyy better than 5A motors from the factory, in fact the best built GM V8 for fuel economy and performance was the 85-90 307. That is why they put them in numerous Cadillacs and station wagons. Don't be fooled by the port size, torque is where it's at. HP is over rated and means nothing if it isn't backed by torque to move the weight. The later 307's were given a bad wrap by the port sizes and people who assume they understand the technology but they out perform the H/O's bar none, that is why they got 8.5" rear ends due to the torque output (which is rather rediculous). The swirl port technology makes for a more complete burn which increases the torque output.

If you were to go with a 5A swap you might as well just install a 350 with all the work you have to do for just 10hp increase. And by the way, 10hp ain't much and the 7A headed motor has more torque than a 5A headed motor and at lower RPM (which is not saying much either) but makes for better drivability and fun around the town performance with better fuel economy:

VIN 9 83-85
180 hp@4000 rpm
245 ft-lbs@3200 rpm

VIN 9 86-90
170 hp @ 4000 rpm
250 ft-lbs @ 2600 rpm

Yeah, all the suggestions about swapping heads and everything really got me intrigued but I still had a notion there was more to the picture since the later VIN 9 engines only dropped 10 horsepower (and gained torque, which I had no idea about). I think you gave a great explaination, at least to someone who doesn't know much about the intricacies of engines. It's good to hear my engine isn't "worthless", at least for decent performance. I'm not really into going fast, but everything that needs replaced on my engine pertains to things that differed between the regular engine from the VIN 9's.

But what significance does the 350 harmonic balancer have? Is there a specific year or type of car it has to come off of? I'm a little confused about intakes still, too. Mine is cast iron (VIN Y). Is there no design difference between the 86'-87' VIN Y and VIN 9, just what they are made of was different?

 

[beeterolds]

Im not crazy about putting a portly 350 balancer on a stock 307 Vin y or not and using it as a replacement for the stock hub type thingy.. the rotating assembly will now be out of balance..

 

[88hurstolds]

The balancer on my VIN 9 is much thicker than the VIN Y's, I heard they were the same balancer used on just about all Olds Motors 350-455 but I could be wrong, it looks identical to the one on my 350 I know that much. The VIN Y's are very thin and look funny. I agree with Beeter on not just slap it on but I would assume if you were having the whole motor gone through you could have it balanced.

I have driven both types of VIN 9 motors and I love the way the roller motor performs, it's almost like driving a car with fuel injection. Also the roller motors can operate at a higher RPM easier than the hydraulic ones but your power is more on the lower end than the Hydraulic motors which makes good for the drivability. The 87 442's had a higher redline (5500rpm) than the 83-85's (4900 rpm) but the 86's didn't get the higher redline tach for some reason.

There is also a much smoother throttle response with the roller motor and you can notice the torque more than the 5A motors. But in reality, when it comes down to running in a quarter mile there is almost no difference. You are really making the choice between operability and around the town drivability more than peak performance which seems to be your objective.

 

[kustomkyle]

Does anyone know what the specs are for the factory H.O. roller cams? I can't find that information anywhere. I've seen .440 or something like that but I need more info to compare with the aftermarket. I've never dealt with this type of stuff before.

 

[kustomkyle]

Alright, I looked at a factory service manual and found what my current (stock 1986 VIN Y) cam specs are:

Lobe lift-
Intake-----6.2738mm(.247")
Exhaust-----6.3754mm(.521")

What I am confused about now is that Clevite lists cam 229-1798, which has the specs as listed above as "1985-1990 VIN Y" as well as "1987 VIN 9". Huh? Did 1987 442's The same cam as a VIN Y engine?

Clevite also has 229-2169, which is listed as "1986-1990 VIN 9". It's specs are as follows:

Intake------.272"
Exhaust-----.274"

Can anyone interpret this as to the right one? It seems like the "1986-1990 VIN 9" one is the true H.O. one because the numbers are higher, but I have no idea what the numbers mean.

The only reason I was able to find the numbers was because I found someone selling a brand new Clevite 229-1798 cam, lifters, timing chain set, fuel pump, oil pump, and various gaskets for $140. It seems like it is the same one in my engine now, but??????

 

[olds307 and 403]

The second cam on your list would be the right one. First find a 3.73 rear out of a Monte SS and swap it in. Then add headers and dual exhaust with an x pipe. You will need a dual hump crossmember. The 307 even with the HO parts won't be terribly fast but definitly better. Get a set of 5A heads mill them to 55-60 cc chamber and get a performer or A4 manifold. A good running Olds 350 or 403 will do better in the long run and will cost less with more potential for power.