Bruce89TA

Hey Guys and gals,

Okay, so I finally got the rebuilt engine together and started.. I think something's wrong with my timing light so I can't use it reliably so I'm not sure if I've got the engine tuned properly just yet..

So I started it up and immediately (well, within 10 seconds) my headers start to smoke and continue to smoke.. "no problem.. probably some oil burning off.." Then it keeps smoking for the 2-3 minutes I let it idle. I shut it off and it's coming off the headers for sure.. I can see the smoke rising off the tubes.. I'm pretty sure it's not oil but I guess it could be and I should run it longer and see if it stops. The supercharger shouldn't be an issue cause we're at idle and the supercharger only kicks in at WOT. I just put in a rebuilt engine and instead of the stock cam, I put in the SLP 51002. here are the specs:

.050 duration 206/214
1.6:1 lift .501/.522
Lobe separation 112

So is it possible that this cam runs hotter than the stock? Of course it's a more aggressive cam so I'm guessing it could be hotter but *that* much hotter? I'm half expecting my headers to start glowing it's smoking so much..

I know the engine had a lot of assembly lube on it so that might be burning off or the exhaust gaskets might be burning a little but it sure seems to be burning a lot.. Any thoughts? Please let me know.

Thanks again,
-Bruce

rezinn

Even if your headers were getting hotter than before, they shouldn't smoke at all. I'm sure the oil will burn away soon. If not, check for leaks.

Recluse

If you got something on the headers (and you probably did) it will take quite some time for it to burn off (with lotsa smoke). Maybe 20 or so minutes and if you rev it up every now and then it would help. Now, if you see your header tubes glowing orange you have a serious lean/excess-heat producing situation. But your case seems normal.

Ed Maher

I'd try giving it some more base timing if the headers seem to be getting excessively hot. Especially if your timing light is questionable, it's too obvious a cause to overlook.
And it's not like thats some wild fire-breathing cam with massive overlap and extra fuel in the exhaust to make things hot. Your poroblem is probably something pretty simple, if anything. I wouldn't worry about a just over stock cam.

u r sofa king we tah did

if the headers are new, it could be the protective paint that is used to protect them in shipping just burning off.

Bruce89TA

Alright.. so the headers stopped burning.. it must have been the oil on my hands when I removed them and put in the new engine.. Now the question is, with the new cam, is there a way to raise vacuum? I realize that the new cam has quite a bit more duration, lift and the lobe separation is larger than the stock cam...
again the specs

SLP 51002
.050" duration: 206/214
1.6:1 Lift : .501/.522
Lobe separation: 112 degrees

Stock 10088155
.050" duration: 179/194
1.6:1 lift: .373/.410
Lobe separation: 109 degrees

I'd like a better vacuum since the fuel regulator is run off vacuum and I'm running rich.. Unless there's a way that I can lower fuel pressure. Any advice?

-Bruce

Ed Maher

Your logic isn't quite right. More vacuum is not going to do anything to help fix a rich problem. A vacuum referenced FPR just serves to keep the pressure across the injector constant. More vacuum doesn't lean anything out, because the pressure reduces directly proportional with manifold pressure. So 45psi at WOT (15psi MAP) is actually ~30psi across the injector. Idling at 20" of vacuum you'd see 35psi of fuel pressure on the rail, with 5psi MAP, or ....30psi across the injector. Magic.

I'll say it again, that cam is barely bigger than stock (stock meaning the good cam, which is on the order of 203/207 @ 0.050). You could not possibly be having a problem based solely on the specs of that cam. Any problem you have, real or imaginary is related to something else. Especially in a MAF car. MAF will run much larger cams than that quite acceptably without any tuning help whatsoever.

First off, have you set the timing accurately yet? If not, then why are you looking for any other cause to a rich/driveability problem when something so obivous is staring you in the face.

Second (assuming the timing is set correctly), what makes you think you are running rich? Scan tool? Black smoke from the tailpipes? Fouled plugs? Could be anything from a sticky/leaky/dirty injector to a fouled O2 sensor from blowby from the rebuilt engine breaking in. Or dirty connection at a key sensor like CTS. Or you put the knock sensor in too tight. Or you dropped your MAF while you had it apart and now it's hosed. etc, etc.

Basically, you just had the engine apart. There are a lot of things to look at and think about. The size of that cam should be the absolute last thing that crosses your mind as far as potential problems though.

Ricktpi

I agree with Ed, get your timing set correctly first. If it's retarded it will overheat the headers to the point of glowing red & destroying most high heat coatings.

Bruce89TA

Ed,
Thanks for explaining the FPR. That totally makes sense now..

Alright so now I found part of the problem.. I had an intake leak. When I put my runners back on, the EGR wire got caught between the runners and the intake so that was leaking..

The reason I thought I was running rich was from my A/F meter. I know it's not the most reliable instrument to use but the LED indicators were constantly in the rich range, no matter what I was doing, accelerating, decelerating, cruising.. It never went into the stoich range. Of course with an intake leak, you'd think that it'd be running lean but that wasn't the case either..

I had the timing right and it was running rich but that was while I had the leak.. Now with the timing set properly, it won't idle. It dies so that leads me to believe, there's another leak somewhere.. I'm thinking maybe a vacuum line needs replacing or I've got a leak in my plenum gaskets (I had to cut them back some to match the porting I did to the intake/runners/plenum.. I'll spray some carb cleaner around tomorrow and see if I come up with anything..

The other weird thing was that my A/F gauge was reading irradically (like it should normally after warm up) at startup which it normally does not. Until it's warmed up, the gauge usually shows lean and as it warms up the LED's migrate away from the lean side. Anyone have any ideas? I'm thinking I might replace the O2 sensor cause it's been a while.

Thanks in advance.
-Bruce