Jeff G 78

Any idea how much weight the Dynamat added?

That's close to 170hp at the crank which is about 20hp over SAE Net when the engine was new.

That's stock? It seems really strong for a stock L28.

I still owe the forum a write-up on my engine, but the short story is that I got there by shaving the P79 and modifying the cam gear and chain guides to get the timing and chain tension right. I make roughly 200 crank hp and my build was done for a very small budget.

I have two flat top L28 engines. One has an N47 with 9.83:1 and the second is a P79 with 9.3:1. When I built the second engine, I skipped the N42/N47 heads I have and bought a P79. I think it's a better head that handles high compression better. Either head will work fine, but I chose the safe route and went with the more robust chamber design for my race engine.

Matt, Have you rolled the car forward or backwards yet? If not, the tires will grab the floor and keep it from settling.

I have a 260 with early SU's and a 280 with FI. An FI system in proper working order is nice for a street Z, but I love the simplicity of my SU car. It fires right up and runs great. If you go with a ZTherapy setup, I'm sure you will be happy. If you ever decide to add a performance camshaft, the stock FI will be very unhappy while the SU's will work great with minor tuning.

I drain my 50/50 mixture into a few gallon jugs and flush the system with water. I then fill it with distilled water and add Water Wetter. At the end of the racing season, I flush it again and pour the old 50/50 mix back in for the winter. I used to drain it and leave it dry for the winter, but it took forever to flush the rust out in the spring.

Yes, I did the eccentric shims in the cam drive. I followed the "How to Modify..." book. The shims came from Summit Racing and they are for a SBC. You need the cam setup sheet, a degree wheel, and a good dial indicator with stand, but the just isn't terribly hard once you are setup. I will post pics of what I did tonight or tomorrow when I have more time. I'm sure I have posted what I did somewhere here. It might be in Guy's engine thread.

I went the other route and didn't shim or change the valves. I modified the cam gear to get the timing right and the chain guides to get the tension right. Works great on my race motor that sees continues high rpm use for hours at a time.

P79 came in '81 though, so if they reverted in '80, it would still be the N47 head.

About 20 years ago, I sent my injectors into Marren Motorsports for cleaning and they told me they were beyond saving. They found me new Ram brand injectors and when they flow tested them, they were all over the map, so they ordered something like 18 more injectors and flow tested them all to finally get a matched set within spec. They were shocked at how much variation they were seeing with the new injectors. The bottom line is that injectors new or old can and will have very different flow rates.

Wow, that's really beautiful. Nice purchase!

Congrats and welcome to the club. I like the front air dam, but I think I'd do something different on the sides and rear.

Yep, backside is correct.

Two things... ALWAYS stuff a rag into the timing chain hole so you don't lose anything down there When you stuff the rope into the cylinder, do it with the piston a bit before TDC. Once the rope is all in, raise the piston via the crank damper bolt to compress the rope and put some pressure on the valve. Otherwise, the valve will open a bit when you use the spring compressor.

Glad to hear it runs! My very first Z was a rusty '72 that I bought for $200 out of a field back in 1984. I flat towed it home and within an hour had it running. The floorboards had been cut out and the seats weren't bolted in. I was so excited that it ran, I sat on the seat cross member and held my feet up while I drove it around the block in the rain. Water was coming up through the missing floor and getting me wet, but it was a blast. After several fast trips around the neighborhood, I drove it home and bolted the seats in. I then drove it around for another 30 minutes with no plates or insurance. I couldn't believe how strong the motor was after sitting in a field for 5 years. The car was too rotten to save, so I stripped the car and stored the good parts. I ended up installing the carbs on my 260 race car after they sat in my garage for 25 years.

Looking good Cliff. Great purchase.

The resistor in the water temp sensor circuit will make the mixture richer, so that should have made the situation worse, not better. A vacuum leak will lean it back out making it run better. As for the original problem, I'm not sure what to try next. What kind of plugs are you using?

No problem. The dip will get worse with sun and air pressure while driving at higher speeds. This will give you an idea of how it can be braced. I'm sure there are many different ways of doing it, but this was the first I found. Just make it weak enough so it will give if hit. Reinforcing the Xenon Air Dam... Pictures - Fabrication / Welding - HybridZ

Looks like Christmas Matt. You might want to search on reinforcing the Xenon airdam. They tend to droop in the center, but a simple brace will stiffen it up without losing the ability to flex if you hit a curb or something.

It looks like a great starting point. How do the rails near the TC mounts look Cliff?

Looks great! I can't wait to see it go together.

For a DD, the 280 is a nicer car than the 240. It's a bit quieter, the FI makes it feel more modern, and the car is a bit safer. If you don't have a burning desire to own a 240, you can get far more car for the money with a 280. The 240 feels more nimble and is more raw, but the 280 is still pretty nice to drive. One alternative is to buy a 280 and put small bumpers from a 240 on it. It will give you some of the 240 looks while keeping the purchase price down.