Hello all,

Well I just got the car back today from my mechanic who put the cam in and had a few questions. The cam is a 230/236 112 lsa, I also had 1.6 rockers and R lifters installed and had the intake & heads ported and installed new ss valves, springs, retainers, etc... basically a whole new top end. As well my mechanic did the exhaust and put in the hooker longtubes, mufflex Y and mufflex single/single 4" exhaust. I also put in a ported 52 mm TB, 28# injectors, and got a PCMforless tune with the LT4 KM. Replaced timing chain, O2 sensors, wires and plugs. All emissions components have been removed (air pump, cats, egr)

First as far as the oil is concerned (I know it's very important to have good oil pressure) I bought a autometer mechanical oil pressure gauge and the readings seem alright. Cold idle is about 50-55 psi, cruising around it's right at 50 psi and warm idle doesn't drop below 30 psi. Do these readings seem about right to you, or are they a bit high? Also A good friend of mine recommended that I make the switch to synthetic oil now that I have the new valvetrain components installed, so I bought some Mobil 1 synthetic 10w30 that I was going to put in after the first few hundred miles. However, my mechanic says he put in Castrol 10w40 non-synthetic oil with Gunk additive and he says that's a good choice for high performance motors. So now I don't know what I should do. Should I switch to synthetic oil now or just stick with regular oil? And if I do use regular should I take my mechanic's advice?
I'm also scared that if I switch to synthetic I will begin to leak oil...

I was also wondering about the break in, what is usually recommended for roller camshafts? I searched the forum a bit and people usually give different advice. Some people say you have to run the new motor for 20 minutes then change the oil right away, then drive 300 miles and change the oil again, then you're ok. Others say break-ins for roller camshafts are not necessary. What I thought of doing is just driving slowly for about 200 miles (not revving too high) and then change the oil, just to see what it looks like. Is this a good procedure? Would it be ok to give the car hell after that or should I still relax for a few hundred more miles?

One thing my mechanic didn't install were the Taylor OTVC wire kit I gave him. He just installed the Taylor wires with the stock mounting brackets and stock routing, from underneath. He showed it to me and they seemed to be routed ok and seemed to be away from the headers, but I've read so many threads here about people burning spark plug wires in the stock location, is this something I should worry about? Would it be a good idea to order some Taylor wires and keep them handy and then just install the OTVC kit myself if something should happen? I also ordered 1200 deg. heat sleeves.

As for the car, it runs REAL smooth when I'm driving around. However I noticed that, contrary to before, it doesn't really like hanging around in the low rpms. Like for example I was just driving real slowly around my block today and I was in second at about 1500 RPM (6-speed) and the car was shaking. Also somtimes at a stoplight I really have to give it more gas otherwise it bogs down and almost dies. I was worried I had some kind of stumble or miss, but my friend says I just have some cam surge in the low rpms and it's typical with 6-speed cars. Is there anything I can do about this cam surge besides shift higher or is it something that I just have to deal with since I have a cam this size?

Thanks in advance.

PS. also I just wanted to add the car sounds AWESOME

 

I'd switch to the synthetic after a hundred miles or so, that will give the springs enough time to shed any extra metal they may have. Your oil pressure sounds like it's fine to me. A roller cam is different from an older flat tappet cam and doesn't require a break in period.

As far as the cam surge goes, talk to Ion about it, he can most likely update the program and tune it out.

 

if you want to help out the cam surge get some gears. The plug wires should be ok in stock location. At least i've heard with Hooker Lts' that stock location is fine. You don't really need a break in on roller cams but it would probably be good to take it easy on the car for a few hundred miles and i would change the oil before i hammer on it.

 

Put a couple hundred miles on the oil that's in there now, then switch to Mobil 1 0w40.

Your oil pressure actually sounds very good- how many miles on the motor? Also, is there much of a difference between the reading on the autometer gauge and the factory one?

 

I was thinking, and inquiring about the same thing.

 

97WS6Scharged, Well it was bryan at pcm for less who did my tune so I sent him an email about my situation. My car isn't really a daily driver (I take it a few times a week) so it doesn't bother me that much, and actually I am learning to adapt my driving style to minimize that low-rpm surging. However I am just wondering if it's bad to drive the car this way with the low-rpm surging that I experince here and there.

Z95m6, I read that gears reduce the surge also, but I'm afraid to spend all that money on replacing the gears on the stock 10-bolt only to have it take a crap. I'm saving for a 12-bolt somewhere in the distant future.

FastZ and SS MPSTR, The engine has 85,000 km so roughly 55,000 miles on it. Unfortunately I can't compare the stock gauge to the autometer because my mechanic said that in order to run both gauges at the same time he would have had to make some type of Y connection at the sensor so one wire could go to each gauge, so since it was too complicated I was unable to retain the stock gauge. However I can tell you that when the car was stock, the stock gauge would show 45 psi cold idle/ 20-25 psi warm idle. This was with standard non-synthetic 5w30 oil.

 

Well I ran into a small problem today. I was thinking about a conversation I had with my mechanic a while ago about blocking off the egr system. I provided him with an LT4 egr block off plate for the valve and told him that he would need to fab one for the other opening. But after feeling around back there just to check things out I realized he must of forgot about that So I've been driving around for about 100 miles with a vacuum leak at the back of the manifold where the opening is that would go from the stock exhaust manifold to the intake.

Am I in trouble or what? I am going to make one tomorrow and block it up ASAP. Could this have something to do with the drivability issues that my car has been having? And could dirt have gotten into the manifold through the opening?

 

Dirt: Definetly. Get it fixed ASAP

Thats also your entire drivability issue. Get it fixed ASAP

 

I disagree. The port from the exhaust to the manifold just supplies the exhaust gases through a passage over to where the valve is. It is the valve's job to let it in. If the valve orifice is sealed with the LT4 plate, there can be no leak into the a/f intake side of the manifold.

Be aware that if you have new headers, the burn-in process can foul/ruin O2 sensors.

 

shoebox, so what you're saying is as long as the egr valve has been replaced with the LT4 block off plate, then there is nothing that can get into my manifold and there should be no vacuum leak? I was wondering why on your website when you talk about blocking off the egr you say something to the effect of "if you would like to block the egr pipe entry on the manifold, you will have to get it elsewhere..." as if it were not required. Whew that makes me feel better.

Spinner you had me scared for a second I thought I was going to have to start saving for a rebuild

As for the O2 sensors, I remember reading about that, and so I told my mechanic that when he installed the new manifolds, that he should reinstall the old sensors and drive around and then install the new O2's. The day before I picked my car up he told me he drove around for about an hour and then installed the new sensors.

 

If you have a block off plate where the actual valve used to be, then you are fine. There are two ports there, and the valve would need to be there to open the passage between them. But with no plate, it would leave a hole open which would be one hell of a vaccum leak.

 

...elsewhere meaning that GM makes the plate to block the valve only and not the pipe connection. There are places online where you can get a plate for where the pipe goes or you can make something yourself.

 

Thanks alot for the help so far everyone.


I'm going to be changing the oil this week since it's been a few hundred km's. I'm not sure what oil to use. So far a few people have been telling me to go synthetic, but I've heard from some others that if your car has been running on regular oil it's whole life, if you start to use synthetic oil it will expose leaks that weren't there before.

Also my mechanic recomended I use non synthetic castrol 10w40 thicker oil, but he is a old-school V8 motor guy so maybe the tolerances in the older engines were such that running a thicker oil was better? And maybe it's not such a good idea for today's "tighter" motors?

 

Synthetic oil won't expose leaks that weren't there before. They will just "clean" then gunk out of the old gaskets and allowing any leaks to actually leak. If your motor has no leaks at all, then switching to synthetic won't start any new ones.

 

Well I changed the oil with a buddy this past friday after a few hundred soft miles (put in some mobil 1 10w30 and a K&N HP3002). The oil seemed fine at the time we drained it, there was nothing on my drain plug and there didn't seem to be any shavings in it it. Although it did smell a little bit like gas (nothing very noticeable though) and now that I drag a magnet on the bottom of the catch pan which had my used oil there appear to be some small metal particles in there is, this bad?

This weekend I did drive it alot though I put about 500 more miles on it in a couple of days, going to and from the adirondack nationals car show in Lake George, NY. The engine drove smooth and oil pressure was the same as usual.