Aftermarket Cams in the 3.1L

[IDCavalier]

I have not added Zn to my oil for about a year, but I did for the first 3 oil changes. The issue started just as soon as I got it together.

I quit buying Zn for a car that has been so problematic!

If it will give me something back, I might buy it some more Zinc! Ha ha

Thanks for the help! I feel kinda like I'm the only 60v6 enthusiast in Idaho! Nobody I talk to around here seems to know anything about them.

"go to a forum" they say!

[IDCavalier]

Thanks! Road trip!

Not seriously. Well, not yet anyway!

I'm running Dynamic EFI's EBL P4 Flash ECM, so I have full access to DTCs and Datalogging. http://www.dynamicefi.com/

The guy's name is Bob. He has been very cool to me since I bought the ECM. (should be! the P4 flash ECMs are $500 if you buy the whole ECM!) That was the most expensive part I've ever put on this car. But there have been times when he had lost patience when I was tuning in circles, but he has helped me begin to learn how to tune.

When I first suspected problems, I ran a compression check and Got 180 psi on five of the cylinders and 184 on number 5 (or was it 6?) --This was before I got the ECM

I followed the break-in procedure with break-in oil + Zn additive. I used that nasty, expensive (but included with the cam) lube on the lobes during install.

You're right, it sounds like I have something else going on!

I checked most of the lifters and lobes when I changed pushrods, everything looked really good.

Upon advice from some local SBC speed shop guy, I used 10mm washers as shims under the studs to attain the proper lifter preload: ~.100"

(that was a pain, miking all those washers to find the right thicknesses)
Needless to say, the car's behavior has been improving since I got the valves to close now. I've heard of valve overlap, but that was ridiculous!

It doesn't surge nearly as much at idle now and it's more consistent in power level. But it's still low in power.

[Superdave]

they are non adjustable and that's fine. Your geometry is stock so there is no need to buy new adjustable studs. Yes, the 1.6 rockers will pick up a little power but it seems like you have something else going on.


Have you checked for trouble codes or (not sure if you have the equipment) datalogged it? If you were close to eastern Iowa i'd just come take a look, lol.


Did you follow the cam break in procedure and are you keeping a Zinc additive in your oil? I almost wonder if the cam or lifter was damaged.

Knock sensor hooked up and good?

[IDCavalier]

Thanks! I got the springs to go with it, but the rocker studs are not adjustable. Bob said that I should have adjusted them, but I can't.


Any Ideas? ARP makes 10mm studs that are 3/8" up to to allow for adjuster nuts to then be used.


Do you think that even with the restrictive top I could gain some more power with new ratio rockers?

The only help I had at the time was a Chilton Manual, but it told me about the 3/8" difference in pushrods, so I made sure not to mess that up.

That's what I don't get. I tried so hard to do it just right, and now I have less power than the tired stocker.

The "new" motor was a 1992, but it seems identical to the one I pulled.

[Superdave]

That cam is pretty much the same as the stock LHO (yes, LHO is the 3.1) cam, this is the one that most people use in the gen 2 engines: http://www.compcams.com/Company/CC/c...x?csid=57&sb=2

you'd need upgraded valve springs, stock will bind and break pretty easy.

Also, upgrading to some 1.6 rockers from a 94/95 Gen 3 3100 will gain even more lift.


Like Ben said, the pushrods won't bend on a cam swap like this unless you mixed up the intake and exhaust. It's a common mistake with the way the heads are set up. IIRC the exhaust ones are about .3 longer than the intake


Comp's lifers are the same specs as stock and meant to be used with the stock pushrods,

[IDCavalier]

Right? I bought this car from my neighbor's Ex gf for $400 and it ran well. Then when the blow-by was more than I could stand, I thought I would rebuild it. Then I thought that I would just put in a salvage 3.1 (first mistake?) THEN I thought I needed to rebuild the salvage one. And, while the engine is out, why not rebuild the THM 125C, right? Point being, I have put like $2000 into a $400 car. The Trans runs GREAT! but the engine has not ever been as powerful as the old, worn out one it came with!

Usually pushrods are bent by mixing up intake and exhaust. Base lobe can't possibly be big enough to case the pushrods to be long enough to bend. After spending thousands on a 3.1 in the past, I can say that I won't do that ever again. I have a stock 3.1 in my cavalier and its going to stay that way minus some headers before I swap in another motor.

[IDCavalier]

Thanks!
Is LHO the designation for these engines (Gen II?)

[IDCavalier]

I used the comp cam p/n 16-115-4. It has .260"/.260" lift, which is less than stock, I believe.
I'm waiting for approval at v6z24 as idcavy93. I hope it comes through soon.
I think the bent pushrods might have been because I used stock pushrods with the aftermarket Comp lifters.

When I tore the intake off to see what was up, my intake valves were coated in some kind of greasy soot-like substance.
Some of my lifters were as high as .300" pre-load: according to Comp, they should be around .100"

[IDCavalier]

I used idcavy93 in v6z24.
The cam I used is a comp pn 16-115-4. It has 260/260 lift which is actually less than stock, if my chilton manual is accurate. But Bob over at dynamic efi was helping me with it and that's when I discovered the bent pushrods.

[SappySE107]

Usually pushrods are bent by mixing up intake and exhaust. Base lobe can't possibly be big enough to case the pushrods to be long enough to bend. After spending thousands on a 3.1 in the past, I can say that I won't do that ever again. I have a stock 3.1 in my cavalier and its going to stay that way minus some headers before I swap in another motor.

[Superdave]

The 3x00 head swap is not as popular as it used to be, most people just swap in the whole 3x00 engine. It's still a good option if your 3.1 bottom end is in good shape though.

Did you use the same username for V6Z24? I know the admin gets a little backed up on new accounts some times.



the base circle should have been the same or smaller on that aftermarket cam. which one did you use?

[IDCavalier]

Oh! This one is great. I didn't know that the base circle of the new cam was different, so I bent a few pushrods before I figured that out! Runs better now that the valves close! Ha ha.

[IDCavalier]

I am just not getting any power out of the new engine. I have been working on it - figuring out the problem. Compression is good : 180 across all six. Put in a flash ecm and I'm running Tunerpro. Got a wb to trim fuel and been playing around with SA. But I think I might need to open up the top end, huh?

[IDCavalier]

I think I might have made a mistake. I installed a comp cams rv cam when I rebuilt the 3.1. This was before I knew anything about this stuff. Ha ha.

[IDCavalier]

I am in the process of joining V6Z24. I heard that a lot of guys are swapping 3x00 heads out on the 3.x blocks.