[Bet Winner]

Originally Posted by madtexan

HAPPY BIRTHDAY WALT!!!

I also turned 50 this year.

So could the smell be caused by the valves not being adjusted right? It doesn't ping at all when I get on it with 93 Octane Citgo gas. It also doesn't have any color to the exhaust. It is clean looking. I put fuel stabilizer (red stuff) into the gas to stabilize it since it hasn't been started much..... anything related to that?

Would doing a compression test tell me something useful?

My vacuum level is good enough to hold my hideaways shut at idle and the idle isn't that rough either.

Mike

I'm not sure about the smell--maybe 40 year old exhaust pipes?--probably not. (My 1968 400 Firebird has its original exhaust pipes--they stink in the garage after driving the car. And Little Wife does not really love it.)

But the idle not being very rough might lead me away from the cam.

A compression test is usually smart. If stock valve train, I believe the nut is just torqued to 20 foot pounds with the cam on its base circle on that valve. Don't overtorque. Adjust the carb at idle too, check the timing. It should probably ping if you get on it with stock compression. Some MaxLead 2000 is what I like.

Oh, I turned 50 in September.

[Bet Winner]

Originally Posted by madtexan

Yes that is what they told me about being a stepped up 068 cam..... but since you have a RAIII block/heads, wouldn't your engine handle the upgrade better than my non RA block? My engine would have come stock with a 067 cam wouldn't it and putting a regular 068 might be just about the limit????? I really don't know but trying to make sense of it all.

I'm sure I have the cam specs at home..... I'll dig them up tonight.

The 4-speed and the 3:55 rear make a bigger difference than the other components. And I have the HC-02 which is quite a step from the HC-01 if I can remember that far back. I stil have an old catalog I think.

[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?

[madtexan]

Originally Posted by Bet Winner

The 4-speed and the 3:55 rear make a bigger difference than the other components.

Agreed as far as acceleration goes. I have 3:23 open in the car. I have a good posi carrier and a set of aftermarket 3:55 gears I'd love to get put in the car but I cannot find anyone who will set it up for me in the Dallas area.

[Bet Winner]

Originally Posted by madtexan

Agreed as far as acceleration goes. I have 3:23 open in the car. I have a good posi carrier and a set of aftermarket 3:55 gears I'd love to get put in the car but I cannot find anyone who will set it up for me in the Dallas area.

The 4-speed and 3:55 allow you to get to a higher rpm quicker which by-passes any lower rpm power.

A little higher stall speed might really help. The rear does not sound like too big a problem--3:23 sounds ok to me, unless you just want to make it steeper.

A older mechanic that worked on these cars might offer some good advice too.

[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

A little higher stall speed might really help. The rear does not sound like too big a problem--3:23 sounds ok to me, unless you just want to make it steeper.

I have the rear end parts so that's another someday project. I guess it would be cheaper to have a higher stall speed Torque Conv installed than to do the cam. But the smell problem............

A older mechanic that worked on these cars might offer some good advice too.

OLDER THAN US!!!! YIKES!!!

[Bet Winner]

With rhoades lifters and the HC-01, the cam is not the problem.

You can bet that someone else on here has these lifters with stock studs/nuts and can say how the rocker feels when properly torqued.

[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.

[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.

[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!!!!!

[madtexan]

Wow!! Leaving work early and helping me out..... If you were local I'd buy you guys lunch

I think they are 16 heads..??... 10.75:1 compression ratio was the stock CR numbers..

I'm going to read the articles you provided. May be above my reading level but we'll see.

Mike

Originally Posted by 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.

Walt

[KEN CROCIE]

madtex--you sure you have an HC-01? We dont normally recommend Rhoads with the HC-01. We do however recommend Rhoads with the HC-02 cam , which would be the higher performance cam for your combo. I missed why you were changeing the cam. If you have any questions or need guidence, please feel free to call me. 909-980-1451

[madtexan]

Ken,
Thanks for chiming in.

I'm 95% sure it is HC-01. I bought it about 20 yrs ago. I really don't need to change the cam but the car makes a gawd aweful smell in the house when I start it in the garage and pull it out. It really doesn't run as strong as I think it should. It idles fine with a very slight lope, has decent vacuum.... holds my headlights closed so I assume it is enough vacuum. IT is an AC car but it doesn't work right now. I'm will call you shortly.

Mike

Originally Posted by KEN CROCIE

madtex--you sure you have an HC-01? We dont normally recommend Rhoads with the HC-01. We do however recommend Rhoads with the HC-02 cam , which would be the higher performance cam for your combo. I missed why you were changeing the cam. If you have any questions or need guidence, please feel free to call me. 909-980-1451

[PontGuy]

Ken, very glad you jumped in to help although its been fun without you. Can you provide your thoughts on how to cam an "original" high compression engine for good street manners/performance with an auto trans given today's gas? Seems like a question that hangs out there but nobody ever really answers. I don't ever intend to go there again (my new engine is set at 9.5:1) but it would be good to know.

Walt

[madtexan]

I found some notes and it was actually done in 1995. It is for sure a HC-01 camshaft.