[madtexan]

OK We got something going here.... The 50 yr old club!

I know the exhaust pipes are not original but they are at least 25 yrs old. I never heard that they can cause a smell though. It happens as soon as the car is started. Smell stays in the garage for days.

I do remember when I put the Rhodes lifters in I had to put a stainless washer under each of the rocker arm nuts. I did that because when I tightened them without the washer the nut would bottom out on the stud (reach the ends of the threads) and not apply any pressure to the rocker arms. They were loose without and I thought they would make noise or come off. Could the heads have the wrong studs in them or wrong push rods or something?

[Bet Winner]

Originally Posted by madtexan

OK We got something going here.... The 50 yr old club!

I know the exhaust pipes are not original but they are at least 25 yrs old. I never heard that they can cause a smell though. It happens as soon as the car is started. Smell stays in the garage for days.

I do remember when I put the Rhodes lifters in I had to put a stainless washer under each of the rocker arm nuts. I did that because when I tightened them without the washer the nut would bottom out on the stud (reach the ends of the threads) and not apply any pressure to the rocker arms. They were loose without and I thought they would make noise or come off. Could the heads have the wrong studs in them or wrong push rods or something?

Rhodes lifters clatter from what I hear. If you are holding the valve off of its seat slightly with this washer, it might very well cause this and might burn valves. A local mechanic that worked on old Pontiacs would really help. I'm afraid to say what to do without seeing it, but this might be the problem.

[madtexan]

Originally Posted by Bet Winner

If you are holding the valve off of its seat slightly with this washer, it might very well cause this and might burn valves.

The washer is under the nut.... on top of the rocker arm. I think it just took up the slack. If I didn't have them in there, the rocker arms would have been really loose. It was almost like the studs were too long.

From what I can remember... 20 yrs ago now..... The studs had a shoulder (no thread at the bottom) that didn't allow the nuts to come down far enough to put any pressure on the rocker arms. My solution was to try the nuts. This was before the internet and this great forum for info.... I improvised! Maybe the Rhosed lifters came with locking nut or something too.

[madtexan]

I think we might be getting to the cause of the issues.

It was suggested earlier up in this thread to reduce the compression. Would that mean a head rebuild with getting port work done to the heads? This would also solve the mystery of needing these washers. I know the heads do not have hardened seat inserts as well.

What would be a reasonable price range to have this work done to the heads?

[Old Bird]

Put some roller rocker arms and poly locks on when you change the cam. You can adjust the lash at zero lock it down and your done. I had issues with getting my valves to adjusted when I went to a larger cam. Went to the roller rockers and poly locks and problem solved.

[PontGuy]

Yeah the 50 year old club, all of us a bit behind the times and still working off what we remember from "back in the days".

Polylocks are definitely the way to go when switching out cams, lifters, valves, etc. And they can be used with regular stock rocker arms, no problem. Without having the pre-load set on the valves correctly all sorts of things can happen, maybe even stinky exhaust! Just getting the heads rebuilt can be enough to throw off the stock adjustment setup. I have run Harland Sharp rollers, and the aftermarket roller tips (again, many years ago), but I actually prefer the cheap stock rockers when using stock or near stock valve spring pressures.

For me, step 1 would be to get some polylocks, get rid of the washers and make sure the valves are set right. Then on to the next step.

Compression ratio is another topic entirely, can't fix that with valve adjustments. I sold the last car I had with the factory high-compression RA III heads 15 years ago, so don't know how it would do on gas today. But I do know that my engine didn't like the available gas much even back then. Running a longer duration cam actually helps make high CR a bit more forgiving but that comes at the cost of drivability. I ended up with a 292 Crane Fireball (lots of duration) but the car was a 4-spd and had 3.55 gears so the lack of low end torque was not a problem. There is no way to reduce CR without getting the heads re-worked, or switching to a different set of heads, or running different pistons. And I wouldn't recommend any shop that doesn't specialize in old Pontiac work- most local machine shops around here haven't seen a Pontiac engine for years.

I would actually prefer the 3.23 gear over a 3.55 for a street car. But either way, if you are going to run a cam with some duration then you will need some slip on the converter or the bottom end will be a problem.

This was all a whole lot easier when gas had lead in it, oil had zinc in it, and Pontiac parts were easy to come by...

Walt

[PontGuy]

I left work early today and since this thread has been a bunch of fun decided to do a little research. I tried looking up the specs on the UD cam you are running but didn't get much off the web. But check out this link for a pretty interesting swap of ideas on CR and camshaft selection from some highly regarded "experts". Be sure to scroll all the way to the bottom.

http://www.davemiranda.com/dmhotrods.htm

Also Jim Hand's articles are always interesting:

http://www.dapa.org/streetmachine.htm

Which head castings do you have? Do you know the CR? If not we can look it up with the casting numbers.

Can you do a compression check on the engine and let us know what you come up with? That will help confirm that your valves and existing cam are working OK. And it also could help with cam selection.

(Also it was the Crane 294 cam in my old car, overall a very similar setup to Bet Winner's. Ran very strong but not much fun in traffic!)

Walt

[madtexan]

Originally Posted by LPete

FWIW, exhaust smell is caused by hydrocarbons in the exhaust (unburned fuel). It's caused by misfire for whatever reason: radical cam with lots of overlap, ignition timing advanced too far, single cylinder miss due to ignition problem, compression problem or vacuum leak (one cylinder doesn't usually make it smell that bad). A rich mixture can do it, but it has to be so rich that the engine starts producing lots of unburned hydrocarbons -- REALLY rich.

This weekend based on what I BOLDED above:
I'm going to check my timing advance and adjust if needed.

Measure the cylinder compression and vacuum level. Question: If my washers are causing the valves to not completely close, that would show up as weak compression, right?

I'm going to adjust the carb idle mixture but I think it makes no difference where it is set.

That will give me a baseline.

Originally Posted by PontGuy

For me, step 1 would be to get some polylocks, get rid of the washers and make sure the valves are set right. Then on to the next step.

If you are going to run a cam with some duration then you will need some slip on the converter or the bottom end will be a problem.

I may already have polylocks installed...... remember it's been 20 years since the valve covers were off. I remember that they had some kind of Hex set screw in them.

After I do the compression test, if the numbers indicate the cylinders are not sealing up properly I'll remove the valve covers and start on removing the washers. Actually I just need to open them to figure out exactly why I put them in there in the first place.

This is AWESOME HELP GUYS!!!!!

[getmygoat]

Originally Posted by madtexan

The washer is under the nut.... on top of the rocker arm. I think it just took up the slack. If I didn't have them in there, the rocker arms would have been really loose. It was almost like the studs were too long.

From what I can remember... 20 yrs ago now..... The studs had a shoulder (no thread at the bottom) that didn't allow the nuts to come down far enough to put any pressure on the rocker arms. My solution was to try the nuts. This was before the internet and this great forum for info.... I improvised! Maybe the Rhosed lifters came with locking nut or something too.

Any chance you still have the original stock "bottleneck" rocker studs on there?.... are you familiar with how all that works? If you are trying to run an adjustable valve train with stock studs it won't work. You need to change over to bb chevy studs.. these provide the full range of adjustment you need for that cam.

[PontGuy]

Not sure whats available now, but polylocks for use with the bottleneck studs were definitely available back when. I still have a set that I used with my 061 "dirt track" heads that had stock pressed in studs (necessary for the class). I ran a lot of different cams with those heads and always got them adjusted right in.

Stretching my memory- Converting to straight-up studs is not a bad idea and I think that the stock rockers still work. I started with Harland Sharp rollers in the engine that I just pulled out and later switched back to stamped rockers, for some reason that I don't really remember. But I just looked at it a few days ago and noticed that it still has the straight-up studs.

The important thing is that all the parts have to match up properly so that valvetrain geometry is reasonable and the pre-load is correct, which is usually pretty easy as long as the springs are not too heavy and set at the stock height. I remember that this can be a whole lot more complex when switching to heavier springs that need a longer installed height though.

Walt

[madtexan]

Yes they were shaped like a bottleneck... relying on memory right now. I'm going to pull the valve covers and check it out later on today. They were stock rocker arms and new push rods. I think I have some kind of locking stud system on top as well. I just remembered I couldn't get the rockers to "not be sloppy loose" so I put the washer somewhere. I'll take pics.

I have no problem buying new rockers, push rods, studs or whatever to get this running right. Does replacing the studs mean I have to remove the heads??

When I bought my goat in 1989 I got the original engine outside the car. I tore it down and then took it to a local shop. He told me the heads didn't need any work and unless I was going to put $$ into porting or something else, he recommended only replacing the valve seals and surfacing the heads so we did that. So he just rebuild the short block assy. So I don't know anything about the heads. They still have the original seats and such. I do remember that I put them upside down and poured gas or some other liquid into the chamber and both valves had a goos seal..... it took a real long time for it to leak out.

KEN CROCIE. I found the original sales receipt and your team didn't sell me the Rhodes lifters. I don't know where I got them or who told me to use them.

[PontGuy]

If you have the 16 heads then the studs are screw in so you can change them easily if you want. I expect that all this may be fine however you did it back then, at least not causing your problems. But if you are going to work on the car to get it running good then worth getting the parts to match up so you don't need washers.

I am more interested in the compression test. Though I wasn't able to find your cam specs on the internet, I was thinking that the Rhodes lifters might not be a good thing with that cam and the high CR heads. Those lifters will effectively shorten your duration at lower RPMs so your effective CR may be way too high. Sounds like Ken is thinking the same and it could be the root cause of your problems. If you get readings over 170 then we may be on the right track. Or if the pressures are all over the place from cylinder to cylinder then you will at least know there are bigger problems to resolve.

Did you get a chance to read through the stuff in the links? I take it you haven't been able to talk to Ken yet.

I am hardly an expert at this any more, but I was big into it back in the 80's and still drawing a lot from that experience. That, and reading and trading notes with the guys in the street forum here the past few months- there is a wealth of information available over there, though a lot of it is heavily slanted toward modifications and street/strip use instead of drivability in stock form. Its one of the reasons I have take a real interest in your situation- there is a potential for some good learnings here.

Walt