kito

I did a summary check of the gasket surfaces and didn't find any signs of leaks. I am using a gasket in addition to the sanderson headers, contrary to their recommendations. I think one thing that's contributing to this impression is that the cabin vibrates quite a bit (from the stiff motor mounts maybe?), which makes it sound much louder inside than outside.

The muffler is the regular 3" oval body offset/offset magnaflow. I'll have to take a look to see what the resonator is, but I won't be back to my car until the 21st. I'm starting to think there must be some sort of problem, because there's no way this setup should be as loud as it is. I'll let you know what I find out.

Yea, putting dual cats in is definitely an option. The question is whether I'd be able to fit them in there. Has anyone done this successfully? Getting cats here in CA is also really expensive (Unintended side effect: I want cats, but the law is making it harder for me).

So I've finally got my LT1 in the Z and it's together enough that I can take it for a drive, but I have one little problem. It's loud. Insanely loud. Shakes the whole house loud. I'm running JTR headers to a Y-pipe, through an 18" resonator, and then out to a single magnaflow in the stock location. I used to be running the same magnaflow on my turbo L6, and right now I'm really missing that sound. I know that 2 extra cylinders and no turbo means it's gonna be louder, but I was hoping the resonator might do a little to dampen that noise. The motor is pretty much bone stock, except the intake and what was necessary to fit it into the Z. The interior is covered in 100 sq. ft. of fatmat with a layer of fiber insulation on top of that, but even so sitting in there is kind of like sitting on the inside of a jet engine. Any suggestions on things I can try to tame this beast? Is it possible that poor engine tune is to blame for some of this noise? It's my daily driver, and I'm willing to sacrifice a bit of power if I can get it as quiet as possible (close to stock-quiet at idle would make my day). I'm really not trying to attract attention to this monstrosity.

Since you're doing the exact same swap as me, and practically in the same city, perhaps you can help me out. I just got off the phone with the ref this morning and got most of the information I need, but I was wondering what you did about the headers. Did you manage to find some CARB-legal block huggers? Also wondering if you could mention any other big snags you hit. Any issues with the evap system or ABS sensors? Did you have to modify your fuel tank to accommodate any LT1 sensors? Thanks in advance for any input you can provide. -kito

This is gorgeous. I really appreciate the write-up. I'm currently in the midst of tearing down my '77 and pulling a LT1+T56 for it, and I'm really tempted by the VR kit. It really is a thing of beauty.

So I pulled the turbo. There's oil in the turbine exhaust flange (going to the downpipe). The turbine inlet flange is clean and oil-free. Seems like oil is blowing by the seals. I think I'll reattach the stock header and see if my smoking problems go away. -kito

Another possible cause could be turbo failure. Thoughts?

Yep, I just inspected it and the only thing holding that outer pulley in place is black magic and some really mangled old rubber. I'm going to order the powerforce damper from MSA. Anyone have experience putting a trigger wheel on those? Could these bad things that happen be related to the plumes of smoke I'm generating? I hooked the stock fuel computer and ignition triggers back up to the engine, along with the stock (unlocked) dizzy, so that the engine management is essentially back to stock, and I'm still making ungodly amounts of smoke at idle. I'm looking at ARP head studs and a gasket kit right now, but it'd really make me feel better if I didn't have to pull the head right now. Still no oil in coolant/coolant in oil that I can see.

Well, to answer my own question, yes, the pulley notch does not match the location of TDC. I pulled the plug from cylinder one and rotated the engine to TDC, and then checked the pulley. The notch was nowhere to be seen (somewhere on the other side where I couldn't see). So I took a sharpie and noted down where TDC was on the pulley as well as on the air conditioning pulley. Then I redid all the base timing setup steps for megasquirt, and it started right up. Timing light showed that my sharpie mark was right at 10º, where it was supposed to be. So I shut it off, reconnected some stuff that I had removed, and started it again. Took out the timing light, and now my mark was at 40º. Oddly, the mark that was on the AC pulley still lined up with 10º. So it looks like my crank pulley is slipping? Can that happen? How do I fix it? Torque down the pulley? Pull the pulley from my '77 and swap them? Does it even matter? I'm at a bit of a loss on this one.

So I ran a compression check, and I got 110-120-120-120-120-120. Last time I did a compression check I got 120-130-130-130-130-130. I'm assuming the difference across the board is due to the colder weather today and is nothing to worry about. Also started it up this morning, and saw smoke in the engine bay, so I shut her down. When I inspected, I found there was a lot of smoke in the J-pipe, throttle body, and intake manifold. Google says my timing is probably off. Sooo.... back to my timing question. How come I can't get her to fire with the timing mark closer to TDC?

Hello all, My first post in years (used to have another account here way back in the day). I'm working on getting megasquirt set up in my '75 Turbo Z, and I've run into a bit of a snag. I got the engine to idle, and I got it running, and then I locked the dizzy and setup MS to drive the coil directly. I went to setup the base timing, and discovered that the engine runs with the timing set somewhere around 40º or 50º BTDC (checked with timing light) at idle. If I were to shift the dizzy to get that closer to 10º, the engine will run more and more poorly until it gets to around 20º, and then it will die. Is it possible that my crank pulley isn't on correctly? I got MS to drive the ignition, but I currently have it setup in MegaTune to fire at a fixed 10º, while in reality the timing light shows it firing around 50º. It was running smoothly though, so I'm pretty confused. I say "was", because the last time I went to start it up it started spitting huge plumes of white smoke out the tail pipe (I'm talking MASSIVE quantities of smoke). The EGR was sitting somewhere around 15.8 or wherever my idle had been, my CLT was about 87ºC, which was also normal. The engine still sounded fine, was running fine, was even revving up fine. It only seemed to be smoking at idle. I pulled a plug, and it looked good. I'll do a compression check in the morning. Is it quite likely that my head gasket is blown (and how did that happen while the engine was under no load?), or is it possible that I busted a turbo seal or something of that sort? I suppose the smoke could've been blue-ish. It's hard to tell at night. Please excuse my noob-ish questions. I've been learning so much over the past week, but I've still got a ways to go. cheers, -kito