johnfharding

Ok. The good news is I got my broken studs out of the heads. The bad news is ,, well I guess there is no bad news.

these are 324 1955 heads. From a performance perspective I'm going to attemp to port match or at minimum clean up the Intake and exhaust ports. I'm not going nuts but getting the flashing out and opening up the ports a bit to more closely match the gaskets. I also opened up the corners on the intake side. I think I have one head pretty good the other head I'm going to try and do the same thing to.

Once I get done doing that I'm wanting to send the heads off for a rebuild. My questions are, should I go ahead smooth out the combustion chambers? What about pocket porting around the valve seats? Will that help. When I have the heads done how much should I have taken off to get a compression of around 9 to 9.5 to 1. I'm wanting to get as much gain for my time and dollar as I can. I will probably end up having the lower end of the motor done but right now I don't have the cash flow. these oldsmobiles are expensive to rebuild.

Any words of advice or things to avoid? I plan on having them magnafluxed, have the guides checked and replaced if needed new springs , regular valve job. etc.

J-(Chicago)

What are the casting numbers on those heads? If 411929 they are 350 heads.
If no I'd like to know anyway for reference purposes.

johnfharding

These are 324 heads from the gen 1 rocket motor. as far as I can tell they are the original 1955 324 heads.

88 coupe

Yes.

Yes.

Assuming you mean "short block" as "lower end" means only a crank kit. Do not mill the heads until you know which pistons you'll be using, as '56 replacements should put you at 9+. If not, there are still a couple of options, but you cannot know, for sure, until the engine is apart and all relevant dimensions are verified.

All of the above, are included in any quality head rebuild. Checking the chamber volumes is not.

Have them CC'd and request that they match all volumes to the smallest one. Whether they can, or not, will depend what replacement valves are available.

Norm

johnfharding

I will keep all that in mind

johnfharding

O.k. I have port matched the intakes and cleaned up the exhaust, I also smoothed the chambers and ported the bowls to the size of the valve seats on both the exhaust and intake. I rounded the short side radiuses and tried smooth everything in. I knocked down any casting flash I found smoothed the rest of the runners slightly to take some of the roughness out of the casting. Finally I took the heads to the machine shop where they found the following.

1. Heads in good shape no cracks etc.
2. Exhaust valves were good
3. Needs intake valves and new guides all the way around or needs sleeves in the guides (machine shop says this may be an option).
4. Hardened exhaust valves seats have been reccomended. I'm thinking yes on this even though its an extra 200.

My question is what should I do on the valves? Should I go with the bigger 56 Intake valves?

I have been talking to Ross Racing and I think from talking with them my lifters are shot, as some of the rockers are beat up pretty bad.

Which leads to a new Cam? What should I do here I need lifters too. Ebay store FalconGlobal has new 55 cams for 257 dollars but I would like to have a roller cam or minimum RV/mild performance cam for that kind of money. I'm not looking for something crazy just something to take advantage of my head porting. I contacted Isky cams but currently they only have the 1956 size cams.

Oldsguy

John, you might look to Harold at Ultrdyne. He has my respect when it comes to cam design and he has been doing it a long time. Perhaps he could guide you to a suitable valve train selection.

88 coupe

Use new guides.

Not needed.

Good choice.

Egge Machine has the lifters for about $160.

Fusick Catalog, page 38, for the rockers and shafts. Or you can try Rocker Arms but I don't know anything about them.

I understand Roto-faze can make you a new blank. From there, most any grinder will add the profile of your choice.

More practical, and less expensive, route is to have your own core reground by one of the same companies.

Norm