I just read the whole popsci article. Fascinating. I think the idea is that as you raise compression, or in this case boost, you're liable to get pre-ignition and/or detonation at some point. The Singh grooves supposedly cause a more complete and controlled burn.

And as to why none of us know more about it, I'm not too surprised as it seems like lots of good grassroots ideas get squashed by large manufacturers for the sake of the status quo. Ever read about the hot vapor engine invented by Smokey Yunick?

Sorry, don't want to thread jack.

I designed a way to use the Fidanza adjustable cam gear on the intake of the BP4W head. So now I will be able to dial out the valve overlap on these cams.
https://www.miataturbo.net/attachmen...ine=1371167973
https://www.miataturbo.net/attachmen...ine=1371167973

I think I deserve some royalties for using photos of my thumb and forearm. I'll be by shortly to pick up my check. LMAO!

No problem, I can pay you with MR BROWN cappuccino.

Your proposal...is acceptable.

I have some more things done to add in here. I drilled a hole in my block (post #4). The idea was simple, because the motor is turbo'ed make an easy escape route for any excess gasses developed in the lower part of the motor. The BP4W head has only about a 1/2" drain hole for all the pumped oil on top to drain back. This is also competing for space with the engine gasses coming out from the bottom. So what I did was a 45 angling up out of the block going through a air/oil separator and returning to the back of the valve cover. The separator is an aluminum tube filled with the same stainless scrubby stuff in the catch can mod. So far it's worked great. I "T" another boost gauge into the line from the valve cover and at idle/driving there is about 3-5 inches of vacuum and at 10 lbs boost it reads zero. Under normal driving low pressure is created through the intake manifold and under boost a one-way valve stops any pressure from going back into the motor. Under boost the is a low pressure area at the inlet of the turbo and that's where the outlet for the catch-can vents through.
https://www.miataturbo.net/attachmen...ine=1371414866
https://www.miataturbo.net/attachmen...ine=1371414866
https://www.miataturbo.net/attachmen...ine=1371414866
The one-way valve is off a Honda brake booster, very robust and will handle over 30psi.

Wait why does the AOS go between the block and the head, that doesnt make sense. Pulling from that spot on the block makes sense, but it should go through the AOS and go to the pre-turbo intake.

What I've done is have another path to vent any blow-by gasses that might not be able to get out of the factory drain back port at the back of the head. Non boosted driving will vent from both the intake manifold side and the catch can side. During boost the intake manifold side closes off and the catch can side functions at an improved rate with the higher velocity going into the turbo.

I have about 1700 miles on the build at this point and I thought I'd get around to doing a compression test.
#1 174.5 psi
#2 172.0
#3 174.5
#4 174.0
This is 9:1 JE with .030 top and .034 2nd.
I haven't tried to adjust out the valve overlap yet (16 degrees) so this could get a little better.
https://www.miataturbo.net/attachmen...ine=1373163495
I have also been monitoring engine blow by. I had an extra fill cap and plumbed it into this gauge I got at NAPA. Everything seems ok, the gauge reads 0 at 10+ lbs of boost.
https://www.miataturbo.net/attachmen...ine=1373163495
https://www.miataturbo.net/attachmen...ine=1373163495

I got a chance to go to Gingerman Raceway for one 0f their "Test and Tune" events Thursday evening. Gingerman Raceway, Ltd.
Had a really great time, made it there and back without breaking anything = win. Tune is better but I wasn't ready for the EBC to take over so I just ran 10psi off the waste gate diaphragm. No issues with the catch-can/oil-air separator so I guess we're done there. Have to work on hot start issues.
https://www.miataturbo.net/attachmen...ine=1373666643
https://www.miataturbo.net/attachmen...ine=1373666643
https://www.miataturbo.net/attachmen...ine=1373666643
https://www.miataturbo.net/attachmen...ine=1373666643

looking good!!

nice
 

i like the attention to detail on the small stuff that most people overlook or leave as an afterthought. Your tryed and tested setups make for a reliable car and confident driver. oh yes and Mr. Brown nice touch. are you suppling that habit yet?

Hey can you define here why it was show not about AOS.

Any updates Jeff? I'm planning a mt.net meet you should make it!

Kind of an update, this was the winter project.

https://www.miataturbo.net/diy-turbo...o-build-79259/

-Jeff

I'm considering porting my t25's, and this thread was always in the back of my mind when I think of stuff like that, I think you did a fantastic job (on both setups).

Can you please share links/pictures or just let us know exactly what tools you're using? Is it just a carbide bit and some sandpaper bits?

Thanks

Hi V, the morst important tool is hr Harbor freight die grinder (@$30) Without coupon. they make a small metal polishing kit also. The die gringer uses 1/4 carbide bits to cut the metals. I will post closeups after this new project gets staeted. 7 pm to 7 am.
nappie time.......

Perfect. Thanks man. I'll wait for those pics.

Cant wait to see this thing at the dyno day...

I agree. Jeff's car was the star (in my mind) of our little get together a couple months back.

I love almost everything about it. In that I mean that the only thing I don't like about it is that it's not mine.