Z Greek

I just re-read your original post. C cam does not look like much of a cam. Also, you say above you do not want to spend much money, but the C cam you are looking at need to be touched up, which will cost you just as much as sending a stock cam off to have the grind of your choice. My two cents!

Alex, I do not know what the specs of a "C" cam is, others on this site certainly will. There are so many aftermarket grinds available, I would not limit myself to just a Nismo cam. I just put together a L28, flat top pistons set .010 out of deck (negative deck height) with a P79 head, and a calculated compression ratio of 9.65:1 (head milled .045), and a isky stage 1 cam (slightly higher lift .475, shorter duration, 270 advertised, 222 at .050) and made 180 hp to the rear wheels. I consulted extensively with Peter at PMC race engines, he was glad to help me with his vast experience with these engines. This engine has great power from 3,500-6.500, (see my dyno sheets on L28 Chumpcar dyno runs on this forum). This engine also just finished a 24 hour Chumpcar enduro in Spokane, WA over the weekend, so it has good durability. Isky is, in my opinion an excellent choice, and they will work with you to meet your goals. They charge around $140 to grind your cam. I had a whole box of cam followers surfaced at Delta cams in tacoma, WA for $3 apiece, some time ago, but isky can probably re-surface them as well. Todd at Wolfcreek is also an excellent choice (he rebuild a set of Solex 44 PHH for my Datsun 2000 roadster a few years ago) Good luck with your engine, there is vast experience within this site, I am relatively new with the L-series engine.

I have some in car video from the race last weekend, my son is working on compressing for it for me so I can post a few minutes of it.

Attached is the data from some of the pulls we made with the L28 I put together for our Chumpcar 280Z race car. If we leaned the carbs (SU's with SM needles) to 13:1 (pull number 8), engine did not like it, and horsepower, and torque curves became ragged looking. We left a/f where it shows in pull number 6. The engine performed very well, and was still running strong at the end of the 24 hour enduro we finished on Sunday. I am proud of the old beast. L28Chump run 1.pdf L28Chump run 2.pdf L28ChumpRunFile_006.pdf L28ChumpRunFile_008.pdf All_Runs_Data L28 version 2.0.pdf

Administrators: I know my thread has strayed away from the 6 cyl. forum, but this thread started as my L28 build for my Chump car, and it looks like a lot of people don't know what the hell Chumpcar racing is. I will return to talking specifically about my engine after this post (I will be posting dyno sheets today). If you will allow me to explain briefly: Chump Car World Series is a race series put together by a great fellow named John Condren. John has raced many different cars in many different series, over several decades. I hope I am not putting words in John's mouth, but I think he put Chump together as a more serious alternative to Le mons racing. Le mons has somewhat of a circus atmosphere, where it is my understanding that other competitors can vote to have a car they don't like for some reason, destroyed. Not for me. Chumpcar is the cheapest way to get lots of seat time in real wheel to wheel racing that exists (over the weekend, for instance, I drove for a total of 6 hours, 2 hours at a time. The format is different race to race, city to city, but they are all endurance races of 7,8,12,16, or 24 hours. That's right, around the clock! In three years, John has grown the series to 64 races in 3 countries. I guarantee there is one at a track near you, CHECK IT OUT! The premise of the series is you must start with a car that has an actual internet value of $500 or less. Here's what that means. Find 10 craigs list, ebay ads, or any viable for sale ad for your car. The car must be "running and driving." The average of these 10 ad's is your aiv. Like it or not guys, they made so many S30's and S130's, and they had such a rust, and owner abuse problem, that this is a pretty easy task for one of our cars. And what a fabulous platform to start with! The car I have been driving, for instance (I do not own the car, I helped build it, and provided the engine), has an AIV of $435. All of this "proof" goes in your log book, and is open to adjustment at tech-in. Any "racy bits such as headers, urethane bushings, coil over shocks, etc, add to your aiv. If your aiv is over $500, you will be assessed "penalty laps, and they add up quick! Even in an endurance race, you don't want to start even 5 laps behind. On a 2.25 mile road course, that is like starting 10 minutes behind, a long road to overcome! Anyway, that is about it. If you are interested, go the the website, and check it out. Chumpcar.com

CHUMPDATE Well we finished 9th out of 30 cars at the 24 hour Chumpcar enduro in Spokane, WA this past weekend. We had a blast, and the car ran great. We had an electric fuel pump fail early, which cost us about 20 laps, and then broke a rear wheel stud changing tires which cost us probably 20 more, I also spun, and made an off road excursion that cost about 10 more laps (I pulled the wiring off of the electric fuel pump when I went off road and had to be towed back to the pits) or we might have been on the podium. (I know a lot of what ifs, and if it was not for that!) My engine ran FANTASTIC. Water temp was rock stable at 190, and oil temp peaked at around 225 during the heat of the day. I ran the beast up to 6200 in 5th a number of times, with 3.9 R200 rear, so the car goes! Huge thanks to Peter from PMC for all of his advice and mentoring. My buddies/teammates did sneak it onto the dyno last week while I was traveling, and they fessed up during the race. The engine made 178 horsepower to the wheels on their new Dynojet 24. The old engine made 136whp on the same dyno. I will try to get them to print me a sheet so I can post it. Ambient air temp was over 90F when they ran it, and maybe even hotter inside the shop. They made one pull with the air cleaner off, and made over 180whp. There was only one car on the track that could out pull us on the straits, and it was an E36 Bimmer (I know, how is an E36 a Chumpcar?!), and it just BARELY out pulled us. The Bimmer won, but was dropped a place when they discovered the ECU had been "chipped" during post race inspection. Lets see, you some how manage to convince Chumpcar officials that you can buy a running, driving E36 for under $500, and then you still have to cheat to win? What a bunch of douchebags! My buddies may run the Z one more race this fall, and then the engine comes home and I'll open it up to see how it fared.

Yup, that's what it looks like to me.

Can't wait to see the youtube Peter. Good luck on the dyno.

Peter (PMC) has been SO helpful and gracious with his advice to me on my L28 Chump racer project. I have been working on cars all my adult life, and love engines but am far from a race engine builder. Peter has never talked down to me, and has offered nothing but brilliant advice. My COMPLETELY stock L28, with attention to detail, and advice from Peter just ran with a pack of E30 Pro3 Bimmers at our local road course on worn out Yoyo 888 tires. Once I got the tune dialed in, the engine is nothing short of BRILLIANT! I owe most of it to Peter at PMC's advice. I will never second guess anything he says on this, or any other forum.

OK, back from the track, we just finished our afternoon heat race. We were in a field with mostly pro3 Bimmers. Engine finally is coming to life. Turns out they run better with all 6 spark plug wires on. We were running on really shot Toyo 888's, and ran in the middle of the pack with some very expensive company. The car ran consistent 1:43's compared to 1:47's with the same driver with the old engine during the last Chump race. I am pretty proud of our old Chumpcar, and particularly my L28. We will finally get it on the dyno next week, and see how close our seat of the pants tune is. Next Saturday, the 21st, we hit the track for a 24 hour Chumpcar enduro. I get to drive 3) 2 hour stints, assuming the car stays together. I was not able to drive the car this weekend as I do not have a conference license. I cannot wait!

Good thought Monkey, cam was degree'd on the stand, I am confident at where it is at for now. We may monkey (so to speak) with it on the dyno next week depending on how the weekend turns out. Main goal is to get it to make some power, and be reliable for the 24 hour Chump race next weekend. Just got back from the track after the morning session. We definitely made some progress with the electric fuel pump, we finally have some color in the plugs. However number 5 plug wire fell off the first lap, so we raced with a 5 cyl the whole time. Lap times stayed the same, so I am hopeful for the afternoon sprint at 3pm with a 6 cyl Z!

Off to the track. Ambient is going to be 10-20 degrees cooler today (high of 80 F), with chance of thunder storms. Hope it stays dry, and hope we found some top end out of the engine with fuel delivery change!

Yup, what six shooter said. I must have still been typing when you posted!

When I have to remove a bare block from a stand alone (or with someone for that matter), I leave the stand "snout" on, and slide it directly into my pick-up, or set it down on the shop floor. THEN unbolt from stand snout. One person trying to hold the weight of the block while the other removes bolts WOULD be disastrous.

Got a couple of lap times today on the new chump l28. Lap times are about the same as the old engine. Engine runs well, and runs strong through first, second, and third gears. Fourth and fifth, it starts to lay down, and will only pull about 5,000-5,200 in fifth down our long front straight. The old engine pulled 6,200 on the same straight. The engine has DRAMATICALLY more power through the first three gears, and through the twisty part of our track. We are running a welded 3.9 R200, and wheel spin is dramatic out of the tight corners, but it runs out of poop on the long straights. We are running SM needles, and have the nozzles down 5 and 1/2 turns. Timing is 35 degrees total. Plugs look very lean on a hot shut down. We are currently running a stock cam driven pump. We are installing an electric pump tonight, and installing a fresh set of plugs to get a read. I'll re-post after our heat races tomorrow. Engine shows great promise, but disappointing to not see it at it's full potential.

Practice day at the track. Engine was strong, but we had a fuel tank venting issue which had us making an emergency shut-down. I was riding with one of my team-mates who is very experienced track driver, I was riding in the buddy seat we installed. All of the sudden, it felt like I was being rained on from the back. For a split second, my mind said "where the hell is that cold water coming from, and how is it hitting me in the back?" Another split second later, both of us realized it was fuel. Power off, ignition off, coast off to the side of the track. We had just re-designed our fuel vent burp tank. We saw the error in our design, and fixed it, but too late for more testing, or lap times. Car will race in an actual conference race tomorrow, and a couple more over the weekend, good opportunity to get some time on the new Chumpengine, and generally get the car ready for next weeks 24 hour Chump race. We painted the car Sunday night, and put the graphics on it at the track today. Looks a little too good for a Chumpcar! I'll post again after the races tomorrow, and let you know how it does against "real" race cars! By the way. Since we decided to paint it, we did not have time to put the car on the dyno. We will get it on before the Chump race, and I will post numbers, good or bad!

Thanks Peter, I'll let you know what it makes!

Just put my new L28 for the Chumpcar on my buddies run-in stand. Will have it in the car and on the chassis dyno towards the end of the week. Sounds pretty good, hope it makes some power! IMG_1175(1).MOV

Milling a P90 head .006 is negligible as far as a change in chamber volume. Do you mean .060 by chance? I just milled a P79 .045, and ended up with chamber volumes of 49-49.5 cc. With .040 over FLAT top pistons milled to .010 negative deck height (protruding .010 out of deck) my compression ratio calculated at 9.65:1. Dished pistons will yield less static compression, but not knowing the volume of the dish, impossible to calculate. I have been using an online calculator that works really well. www.csgnetwork.com/compcalc.html

Wow, Peter, that is some impressive engineering.

The "notched retainer thing," sounds like the lash pad. With the cam follower "knocked off to one side," that cylinder was completely dead, engine would have been low on power from this alone. It was probably making a hell of a racket too. Look very closely at the cam and cam followers on all cylinders. Also make sure the spray bar is intact. Now that the engine is out, it is very little work to put it on an engine stand, flip it over and pull the pan off. Pull off number 6 rod cap (furthest from the front) and look at the condition of the bearing, and rod journal. If it looks good, you may want to pull a few more and examine just to be sure. Keep the caps in order, they are numbered, and the numbers must line up when re-assembling. If it looks bad (deep lines, copper showing through, etc), it will need major crank work. Take a picture and post it. Many good engine guys on this forum, from a few detailed pictures, any one of them can tell you whether to do a minor repair on your head and put it back in, or go to plan B. Good luck!

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Duragg, I was just reading the details of your engine under your post. I am currently putting together a similar engine. Same cam, flat tops set to .010 out of the hole, P79 shaved to 49cc (should yield about 9.6:1), SU carbs with SM needles, stock "match box" electronic distributor, 6/2/1 header. I have consulted with Peter at PMC engines quite a bit on this combo, what a nice guy! Your horsepower number is impressive. The engine I am replacing is bone stock, and put 139 to the ground on a brand new Dynojet 24, so I have a good baseline to go from, if I can find 25 more HP, I will be thrilled. I should have it together and in the car in 3 weeks or so, very anxious to see what kind of power difference I see. By the way, was it a single grove, MSA damper you did something to you will never admit? They fit damn tight, hard to tell if it's just tight, or if you're wadding up the woodruf key. Whoops, did I just say that out loud?

"Fix that thing I will never admit to with the front pulley" I did something to a front damper/pulley once that I will never admit, I wonder if it's the same thing?............

Good Point, TimZ