Leon

When I was at WORKS Motorsports, we developed the only CARB-legal BRZ/FRS turbo kit on the market. FYI... The car is a blast to drive all kitted out (or bone stock). The WORKS shop car has a Flex-Fuel Stage 2 kit, Ohlins, STI brakes, etc etc. I've driven it on track from stock to modified and it's an absolute beast.

I had a similar failure on reground rockers, also on the trailing side of the pad. I think the trailing side sees more wear because as the cam lobe sweeps across the rocker pad, the lever ratio over the valve spring is increased. This puts more stress on the lobe/rocker interface the closer the lobe gets to the rocker pivot. Mine failed using a "good" oil, Brad Penn. Once I replaced the REGROUND rockers with new (combo of aftermarket and Nissan) they've been wearing in really nicely. Only have about 500 miles on them though... I didn't do an engine teardown, just changed the oil.

That doesn't look too good. I'm not a fan of Royal Purple, can't explain it scientifically but they don't have a great reputation. Try switching oils to whatever your cam grinder recommends (I run Brad Penn based on Ron Isky's rec), maybe consider replacing the rockers with new ones. Were they resurfaced or new?

You need to take it to a frame shop and have them measure it.

S2000

I'd take it to a frame shop.

Did you double-check that you have the springs in the correct locations? A left-right spring rate mismatch will cause weird side-effects. Who built the coilovers? Are the collars located identically left-right?

I bet Dinan would have some great insight if they like to talk about projects like this. http://www.dinancars.com/

Just because wires are going to the right places does not necessarily mean that the ECU has all the proper inputs to make it happy. I'd get together with somebody that has a lot of knowledge regarding the ECU for that car, i.e. an old-school BMW tech. Maybe there are good explanations online, although I'm sure you've done a lot of that research already.

Man, the wife and daughter are a tough crowd! Glad you're enjoying everything, it's sounding like a great trip.

Love the car and setup, thanks for the feedback!

I used an L24 head gasket on an L28 bottom end! I admitted it to Dave and he showed me an easy way to visually tell between the two: the OEM L24 HG oil feed hole is round and L28 HG oil feed hole is oval. Another one of those mistakes that I definitely won't repeat again! Not sure what size the E31 chambers are but will definitely stick to the P90 at this point. Not that I have a knock sensor in the block but surprisingly I didn't hear much in the way of knock in the 1500mi that I put on the engine. Dave indicated that with the right build and tuning, 11:1 comp can be okay to run on pump gas. I was using an OEM head gasket which compresses TO roughly 1mm. I'd like to repeat the test that I screwed up when first assembling the motor: with a dial indicator mounted to the block, measure head height with no gasket installed vs a compressed head gasket. That will give me a more-or-less exact figure of the true compressed gasket thickness. I plan to use an OEM L28 head gasket because this motor isn't that special in the sense that the pistons are stock replacements and pop out of the deck as much as a stock piston would, i.e. as Nissan designed it. I ran it by Dave and he says he uses OEM head gaskets in many of his builds, although he is not fully on board with how much Nissan designed the pistons to pop out of the deck. Looking back at the previous measurements, my piston-to-head clearance is 0.017". I did not see any signs of the pistons hitting the head, although I don't think I ever spun it to 7000RPM. I'll be able to re-measure that once I get a compressed gasket thickness, as I know the pistons are 0.021" proud of the deck. Time for some more learn-by-doing...

Thanks Garrett, means a lot that you took the time to do so! Good ol' days indeed, wish I could go back in time and do it all over again but better. Hey, at least you had more quality time to spend on the Z! I have to be so thankful to my wife for putting up with me, she's the whole reason I got my first 240Z. Without her, I may have been stuck working on some shitty 944. My philosophy on this project, or any project, is to do the best I can but to also not be scared to try things out and "learn by doing". Mistakes and failures are not a negative but a learning experience. Frankly I've been expecting issues to pop up as it's the first motor I've ever built and the first go-around is never perfect (something my mom had to teach me every time I'd throw a tantrum after breaking whatever Lego model I was building). I've learned tremendously from the mistakes I've made so far which ensures that I won't make them again. It's my pleasure to share what I can as I've learned an incredible amount of information from the many experienced and generous people here. Plus, this gives me an excuse to have a head build by Dave...

Nice job! Making good progress on an interesting swap. Looking forward to hearing it run even if it's just on the stand.

Wow, that's super cheap!

That's part of the fun! Good engine shops are hard to come by. I'm willing to pay for good work and am lucky to have Rebello an hour away.

LOL, I think we have an answer! Just came back from the Rebello. The #1 exhaust valve guide completely failed and the rest of the exhaust guides were on their way. Motor has about 1500 miles on it. Dave blames the valves and maybe the stem seals. Going with new Nissan exhaust valves, Supertech intake valves, and different stem seals. All of this reminded me of this thread. Looks like you were right Steve!

The head is in Dave's hands, had a great conversation with him this morning. It's mid-season and man that shop is packed! The #1 valve guide was completely destroyed and the rest of the exhaust guides were on their way, very loose. Dave blamed the SI valves and possibly the valve stem seals so we're doing new Nissan exhaust valves, custom Supertech intakes, and different valve stem seals. Also getting some port-work done while we're at it. Should be fun once I get it back on the road! Edit: we did some calculations and realized that my compression ratio is close to 11:1 and not below 10:1, like I had thought! This is based on 44cc combustion chamber, pistons .020" above deck, and .020" piston-to-head clearance. Looking forward to getting this setup dialed in!

Thanks Jim. I really appreciate the offer, I think you may have even sent me some used gaskets in the past for this same purpose! If I go with OEM, my compressed thickness should stay the same which would mean my piston-to-head and piston-to-valve clearances shouldn't change either. Just have to make sure to get an L28 gasket this time... I finished disassembling the head last night and will be dropping it off at Rebello tomorrow.

Looks like it's time for another round of, "damn, I f***ed up!" Pulled the head after work today: Turns out an L24 gasket doesn't work on an L28... Another example of why rushing is bad. I'm guessing the gasket is for an L24/L26 as it protrudes into the combustion chamber in certain parts of the bore after being crushed. I didn't see evidence of valves hitting the gasket but I haven't taken a close enough look yet as I just pulled it tonight. Planning to get an OEM L28 headgasket if they're still available. In related news, I spoke with Dave Rebello about the head and am planning to drop it off at the shop on Saturday for repairs and some minor port-work.

Make sure to stop at Rainbow Pools on your way to Yosemite. Bring your swimsuit! Two Guys Pizza in Groveland on the way to/from Yosemite is the best pizza I've ever had, we go every year. Highly recommend stopping there, it's just off Highway 120 in Groveland.

Don't start comparing vacation spending to how much money you could've spent on the car. It's not the path to happiness!

Nice! That's a pretty busy area but you're near GGP and if you want to see a nice panorama, you're right by Grand View Park. Make sure you check out Twin Peaks if it's clear out, day or night. Fog in the Sunset doesn't necessarily mean it's foggy elsewhere in the city! A common occurrence in the area...

Welcome Keith! Are you staying near Cole Valley?