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I saw your FB post and Ed Toomey was saying 1mm.

He's probably saying that because many are a little sloppy and get it wrong once you start dialing it down closer. It's easy to be too tight on one side and that can cause issues.

Probably the best recommendation is to get the doweled so that you get that variance in orientation removed. Thus avoiding a tight spot that's even tighter than what you have.

Must have been an epic squeeze to get that together.

I'd think more hardening would lead to more failures like seen here. You need ductility. Surface hardening is a factor in that break, or if it was, it's where the stress riser started.

Either way, this one was cycled out.

I'd say the head was a success for sure. We ended up one fatter on the needle jet, but on the leanest position with the needle. The power is what you'd expect while on the pipe but I found we were with more mid range. I was able to run a gear higher in the slow corners and it still pulled off corner. One session was in the wet and I felt downright comfortable in the car, and in fact, I would have been the fastest car overall by a long ways in that session if it weren't for the session getting cut short. That speaks to the reasonable drivability of the engine.

There is some electric issue that temporarily knocks out the left side cylinder spark. We rearranged wires and spark returned. Asides from our typical overheating (pretty well narrowed down to low airflow volume) and the intermittent lack of spark on the left cylinder, the engine was a monster. Even with overheating we finished our sessions this year.

I lead the race after starting fifth. A guy unfortunately tagged me and spun me. I recovered and finished 12th of 20 or so cars. Since I do not have reverse, I had to wait for corner worker powered reverse, and I fell to dead last on the circuit. So I made a decent recovery. We were good for second or third this year. I do not think we could have kept full pace due to the overheating.

We had a really nice time though. The brakes were great. Overall the car was pretty pleasant and drama free. I saw over 2g's peak lateral and sustained 1.8g. This is very good for a non aero car. The van worked great and got a ton of attention. I got a few unsolicited offers on my RD350 that I turned down.

Overall a very fun weekend!

Well dudes, load in is tomorrow.

We actually loaded up the trailer on Monday. The car prep was done.

Since last running we replaced the copper radiators with new aluminum ones. From a material perspective, the aluminum ones should be worse, but we suspect the copper ones were full of junk.

Will it cool better? It's not clear yet. It is however obvious that we are getting a good flush on the system, no airlocks to be found. The new rads have caps whereas the old ones didn't have a means for release air at the tanks.


The water pump developed the classic trans oil drip. We pulled it down and installed a new mechanical seal and new shaft seal.

To run the car lower we added some extra fender cooling. I.e. the wheels were rubbing inside the top of the fenders. We removed that material and added louvers to cover the holes. This should let us get to the 40mm ride height I want to see with the car.

Otherwise, we fattened up the needle jet and hope for better mid range response.

No other changes were made.

I got the RD350 back out and it will be at the track too. I haven't ridden it much in at least a year and it was a little shabby. I ultrasonic dipped the carbs and added fresh fuel and it fired right up. The brakes felt good. The lithium ion battery was sitting at 14v no issues. It stopped dripping trans fluid, so it's probably low.

Tomorrow is load in, have to do all the bullshit with the bureaucrats, then we will ride the car down to the visitors center in the parade. I will get some video to post.

It looks unfinished to me. Like they polished some parts to try and make it look done.

Additive manufacturing is ideal for pipes though. Pretty sweet.

Any time you get near the salt it's best to use something you you don't plan on owning.

I've spent my fair share of time at Mid Ohio over the years. I have never made vintage days. My one buddy always camps and invites me every year. Maybe this year I will try for it. It's the week after the vintage grand prix in Pittsburgh, those two weekends usually overlap.

Parallel thinking? Is that the term?

We struggle with fuel economy with the car. The 5 gallon fuel cell is barely enough to finish a half hour session. I think we calculated like 7mpg. So larger jets could be a problem there.

I talked to my dad after that last post, and without any prompting he says that we should pull those red filters and go up a main jet size. I about died. He's waiting on parts for the van so maybe he will do it before the test on Wednesday.

You are correct. I know many have experienced this in other scenarios too. We tried the car without the red pre filters and sure enough it went lean.

The truth is that we don't see enough track time to chase these types of things. Usually encountering other failures that distract us from really tuning the car and engine. Such is life in grassroots motorsport.

When I was driving professionally and we had mechanics and engineeers etc., the expectations were much different.

I finished prep on the car Saturday and it was ready to load. After testing the van while towing the trailer we decided to postpone our test at Nelson's until next week. I was watching the data on the transmission temps and when the torque converter slipped for any period, temps would climb pretty quick. This is with additional cooling we added since my last post. In my last post we noted high temps without the trailer. The additional cooler meant normal temps sans trailer. Then we tested while towing and found high temps again.

We have a lot of hills to climb in our region. Luckily we had penned in this coming Wednesday the 25th as a potential backup date. Hopefully the weather is good. The van should be ready. I am fairly confident the new cooler arrangement will solve the over heating issues. We should have it together today or tomorrow.



Bonus shot of the Mini. It hasn't been outside much. This is a project for August. It hasn't run much since we did the standalone ECU. I am looking forward to it. Maybe my dad will get the new composite hood painted too.

I run mine very much the same as Mark, specifically his second photo with the FZR upper looks nearly identical to how I run mine. It would be cool to machine a plate style upper triple, could drop the clip ons some but still have them high-ish. Maybe I will do that once we get through the race in July.

I stuck with the FZR stem but I shortened it. I converted to tapered rollers to accommodate.

I have a fzr front end in my RD as well. I stuck with spokes. It's an easy conversion and well worth it.

I do the GT750 heads on the mill, the hardest part is fixturing them. Never met two of them that weren't fairly different. Not sure on the head you have, but it's certainly possible to do heads on the mills.