Can a cam be swapped with engine in the car (69 GTO)?
 

Hi,

I have a 69 GTO 400 Automatic with AC and was wondering if the cam can be changed while the engine is in the car? If yes, what gotchas will I run into?

I don't know if this question can be asked but here goes: Is $800 a fair price for a shop to R&R the cam (I provide the cam and lifters) if I pull the engine and deliver to them?

Thanks in advance.

Can be done with engine in car, radiator/condenser will have to come out. RE $800 thats allot of $$, since you are doing all the hard labor. I did the same job in my 71 GP years ago, didn't have to remove the rad/condenser though. You can do it! Dave K.

1st, yes the cam can be done with the motor in the car. It's a big PITA though, especially with A/C. The radiator needs to be removed of course and then the A/C condensor needs to be removed, or at least loosened so it can be lowered out of the way. I was able to do mine without having to open the A/C lines. Lastly you'll need to remove the brace that the horns mount onto in order to get the requird clearance to get the cam out and back in.

2nd, $800 sounds high for a shop to change the cam with the motor out of the car and delivered to them. With the engine on a stand it's a relatively easy job. I wouldn't think it'd take me more than a couple of hours to change a cam with the motor out, allowing easy access to everything. And I'm not even a mechanic.;)

No need to remove engine to swap cam. Remove radiator and un bolt vertical brace behind grill , and the cam will just fit in/out. If you have never done it before, you could probably do it in a weekend. If you are familiar with the exact procedure it can be done in a few hours time. I cant speak for the shop price of $800, but dont see a reason to remove the engine. I would bring them the whole car.

I've done it twice.
No sweat, but an aching back.
I did it in car because I didn't have the room or a hoist or an engine stand.
Careful to drain ALL the coolant out of the block.
The condenser needs to be moved and the strut that supports the hood latch will need to be loosened and swung out of the way. I used the t-handle that you pull to open the hood as a helping hand in guiding the cam thru the bearings. Great time to do some detailing and cleaning while you are in there.

Wow! Thanks for the quick replies.

What about the cam bearings? The machinist said they should probably be changed too. The engine rebuild only has about 2k miles on it in the 20yrs since it was put in. One other thing the shop said was that Pontiacs are notorious about the crank & cam not being properly aligned even thoug the marks indicate that they are so he said they would align that correctly. I'm assuming he meant to timing chain marks being aligned.

Why the concern about getting all the coolant fluid out of the block if it's going to stay in place?

I thought the $800 was high but thought I'd check with the experts :)

Reason i'm doing this is the cam in it is way too hot for the basic stock engine. So the exhaust stinks and the wife gives me grief every time I start it so it hasn't been run much.

The AC isn't hooked up so I guess removing the condenser wouldn't risk any more contamination on the system.

Pontiac cam bearings don't wear out that quickly. If they were replaced 2k miles ago they should still be like new.

You need to get the coolant level down below the waterpump holes so that it doesn't spill down into the oil pan when you pull the timing cover.

What would be the best way to do this? Use a wet shop vac? Draw it from what locations?

I drain the water out of the block by pulling the lower radiator hose off the block. Gravity takes care of the rest. Just have a drain pan underneath to catch the water if your concerned about that. By the way, if you were willing to pull the engine to deliver to the machine shop, why not pull the engine and swap the cam yourself. As stated its very easy to do with the engine out of the car.

I've never been able to get mine low enough in the block to keep it from leaking. I jacked the back of the car way up to promote better drainage and then dropped it back down so the level was below the holes. You could also just pull the block drains I'd imagine. If you get some in the crankcase drain the oil and rinse the oil pan out with a cheap qt of oil.

You guys ROCK!

ONe more question please?

So what the mechanic said about Pontiacs can and crank not truely being timed properly even though the timing chain markings indicate it is..... is that true or rare?

I wasn't really willing to do this. Having to pull the engine just to change a cam made it highly unlikely it would get done anytime soon :( If I went through the labor to pull the engine, I'd have to do some extra rebuilding of the block... and that would be $$$$.

I hope you let it down slowly instead of dropping it :)

Could I hook a shop vac to the lower rad hose location on water pump and suck out the fluid?

Your Green 69 looks just like mine. Black vinyl top, hideaways, cragars, Dark metallic green (mine is 2000 Trans Am color color).

I would think...
 

that for $800 or less, you could pay a competent mechanic to swap out the cam in the car and degree it as well, which would erradicate any possibility of a timing snafu...which is indeed rare from my experience. JMHO. Good luck. Ron

I was tempted to respond last night but saw you were getting plenty of help.

I never heard of Pontiac cam/crank timing alignment problems. Is he talking about degreeing the cam? Even if it is out a bit it does not sound like you are looking for a race tune. For a driver you can just install the cam straight up and be done with it, definitely not worth paying extra money to have someone degree it. And I wouldn't worry about the cam bearings unless you suspect a problem- cam bearings are not typically a problem area. It sounds to me like the shop just wants to do a high-end job and make extra money.

Changing the cam in the car is easy, I have done this several times. As already said you just have to get the radiator(s) out of the way. If you don't want to do it yourself you should be able to find a shop willing to do this for you, though you would have to pay for the extra work involved.

Getting a little water in the oil pan is not that big a deal, although should be minimized. In addition to raising the back when draining I have lifted the front end when removing the TC cover which tilts the engine back just a bit. I never thought about sucking water out using a wet vac- worth a try.

Pack a clean rag in the oil pan gap when you get the cover off and clean up the old gaskets from the surfaces before going any further. At the end of the job you will still have to clean up little bits and pieces of junk that get down there. Then flush it out with some oil as already mentioned.

You didn't say whether or not you have ever installed a Pontiac cam before. If so then you know the drill and if not then you can get more good advice here. Just curious- what cams are you considering? Never heard of one that cures "stinky exhaust" :)

Walt

A little more history guys.

It is a base 350 horse GTO engine with old Hooker tube headers. GM HEI distributor that I recurved (weights and spring changed) based on an article in High Performance Pontiac around 1990.

I installed a HO Performance cam called HC-01 ~20 years ago. I installed it myself and I thought I did it in the car. That's why I was surprised to hear the mechanic say it should be removed. But then I thought that maybe I did it before I installed the engine. I would have used the Green Service Manual for reference. Gettin old and senile.... can't remember exact details :p This cam has higher lift than RAIII and a higher rpm power curve but tamer than RAIV. I planned to install a higher rpm stall converter to help it run better but never did. I did install Rhodes anti-pump up lifters to help the idle/vacuum smooth out which was rec'd by HO Perf when I bought the cam.


I sent my carb (orig Q-jet) to Cliff Ruggles who was highly rec'd here about 5 yrs back to get it rebuilt and I did that. I thought that would fix the nasty smell. People who have smelled the exhaust said it is running way too rich. We figured it was because the Cam Overlap was too much and it was dumping raw fuel out the exhaust. Since the car didn't get run much, I replaced the gas tank about 7 yrs ago but smell is still there with new tank and fresh gas. I burn 93 Octane from Citgo. 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.

I think it also lacks in low end torque for a 400 GTO engine. I thought that would be another symptom of having to hot a cam in the car.

I really appreciate all the help. I really want to remedy this problem this fall since the weather is nice to work on & drive the car.

LOL, I didn't catch that at first but have to reply since I now get it! :):)

But seriously I am considering a regular 068 grind. I'm also going to pull the old tube headers and install the D-port RAIII manifolds and a 2 1/2 inch exhaust with X pipe.

Mike

Mike,

I have the same issue with being over cammed in my 68. Unfortunately, I don't even know whats in the car as this is the way it came. Low vacuum, poor bottom end power, stink and lots of black smoke on launch.

Let us know what cam you eventually go with as I am thinking of swapping in an 068 grind but don't know what the best options are.

Thanks,

Jason

I can relate to old and senile, I turned 50 today. Just got back into all of this after a 10+ year layoff and still remembering stuff myself, and also finding that things have changed a bit during the past decade ot two!

If Cliff's carb didn't solve the problem then I doubt the real issue is running rich. But it sounds like you still have the high compression heads which is something that you should think about addressing. Just about everyone has reduced CR to around 9.5:1 or so in order run today's junk gas. Maybe that's the underlying cause? If so reducing the cam duration is probably not going to improve the situation- though I think you are right about it improving drivability.

I have a high lift version of the 068 style cam in my new engine, and currently installing the RA manifolds and 2-1/2" X-pipe exhaust. So understand your thinking.

Walt

I have a Ram Air III 4-speed with the 3:55 rear that had the original type cam when I got the car. I rebuilt the engine in 1980 using the HC-02 cam from H-O, larger screw in studs, their springs, poly-locks, etc. Everything appears stock from the outside and have the original 28273 carb. In 1980, this cam apparently had a little less lift than the later version HC-02. But this is the HC-02, and the car runs great! With a little more stall speed, I think your HC-01 cam MAY be fine, but I don't remember the HC-01 specs--but I think it was fairly tame on the duration. The duration, not the lift might cause a low end power problem.

I do think the HC-02 would be too much for a stock automatic 400, but you might find the duration specs to review before pulling the cam. The HC-01 was H-O's "one step up" from stock I believe. They knew what they were doing.

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

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.

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.;)

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.

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?

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.

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.

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............

OLDER THAN US!!!! YIKES!!! :)

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.

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.

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?

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.

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.

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

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

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.


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!!!!!

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

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

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

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

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

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.

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

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.

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

I thought I'd share a few pics of the car you are helping me to repair :)


OK. I was able to measure the compression easily on the front three cylinders on each side of the head... I figured it was good enough for now to give us a starting point. Driver side front to rear 170,170,168. Pass side front to rear 150,165,162. I checked the accuracy of my compression gage against two air compressors I have with gauges and they all measured within 3-5 pounds of each other. The 150 on the pass side is of concern.

Now about the rocker arm / valve assy.

I was wrong about the washer being under the rocker arm. It was just above the swivel nut or whatever you call it. So it was just under the poly locks. See picture showing the order in which they were installed.

The studs are removable with coke bottle design. See pic.

I also included a shot of the spark plug. THey all looked the same. SLight greyish brown color. Dry too.

I forgot to mention that there was a splash gaurd over the valve assy that I removed. The cylinder from which I took the rocker arm assy apart had no tension on it at all. The valves were fully seated and it was one that the compression measured 170. I removed the washer and screwed the poly lock down and it bottoms out on the stud shoulder. The hex nut was removed from the poly lock so it wasn't bottoming out. With it on there like that the rocker arms are very loose and I'd be afraid to start it with them like that. Even with the washer in there, it still leaves it pretty loose in my opinion because the push rod spins very easily.


IMO and I am no expert on this........ either the valve stems are too short, the push rods are too short or the lifters (Rhodes) are too short. Or the studs are too long. Something is keeping it from allowing me to set it up properly thus the washers were thrown in there.

Now I rely on all your help on this. ;)

Thats a really nice car, need to get that one running right!

The polylock shouldn't bottom out on the stud shoulder! Since we are doing pictures, here is one of the old bottleneck studs and polylocks that I dug up. The first pic shows them separately and the second shows the lock screwed down all the way until it runs out of threads. You can see that the bottom goes well below the shoulder. And if you look at the wear marks you can see that it will adjust down well below where the rockers were running on whatever cam I last used. So plenty of adjustment. Maybe your polylocks were designed for use with straight-up studs (or a Chevy?)

So you need to find some new studs and/or locks that match up to make it work right. Everything else looks fine to me and then you should be able to pre-load the lifters properly. This has to be step #1.

The compression numbers are pretty high but not as high as I was afraid they would be. If the valves are not set properly then I would think you might see some scattering in the numbers. So the jury is still out on that one.

Walt

If you replace the screw in studs, you can always use 7/16 studs and corresponding polylocks. Stock is 3/8. The 7/16 are stronger of course, but either should be ok. (Keep any stock stuff that you have.)

You can get an approximate adjustment before the engine is started. After warmed up, I take the valve covers off, start the engine and back off the adjustment til the lifter clatters. Then I tightened almost one half turn down and lock them. You can leave it a zero lash, but the engine will clatter more til it is warm. Have some old towels ready to catch any oil.

I would replace the rhodes lifters--could these be ones for a chevy? I vaguely remember that they are different--but I may be mistaken here. But you don't need them with the HC-01, and they may be causing some adjustment problem.

You may not be able to use the splash shields with 7/16 polylocks because they may be too high, but the polylocks should be high enough for much of the oil from the rockers to hit the polylocks and fall on the rocker balls.

I apologize if we are giving you too much info here.

FWIW I've done cams "in-car" as favors before in less than 8 hours, and if you figure $60 an hour, well, do the math; $800 is high. Find a friend to help..