If you think you can run more CR (which I agree you can), but already have the 12.0:1 pistons, why not mill the head?
The BP head looks like it has a lot of meat in it and it would be awesome to make the quench pads bigger.

Ive seen some guys running 14.0:1 CR on 93 octane with Honda D16s (not a performance engine by anyone's definition) by milling the head a lot ,maximizing quench.
This was a drag engine, so I can imagine with a road race engine you wouldnt want to go that high on 93, but on E85 it might not be that outlandish.

I havent looked too closely at the cams you plan on running, but If you retarding the inatke valve closing enough the dynamic compression might be low enough to allow for substantially more static CR. There is software that calculates it, but Im not sure where you find it.
Example:
https://www.miataturbo.net/attachmen...ine=1379047016
People have been taking advantage on the "VVT" on the coyote engine to throw lots of boost on top of the stock 11.0:1 CR by retarding IVC.

It's a non issue. Even on our high our motors the wear is modest. On a street motor, the wear is nil. I don't think you are going to find any cheap way of eliminating bearing and ring wear on an undersquare motor with stubby rods spun to 8k regularly. The trick is either not to spin it 8 often or buy an S2000.

I have a Maxim sitting at my house you can borrow for testing for a few days.. just for the giggles n shits. I'd be curious just to see the sheer numbers

I see no mention of Stahl headers. You have a few flavors to choose from, and they are reasonably priced.

This project is going to require reaching for small fruits at the top of the tree. A bunch of 1/2 horsepower increments will eventually equal the 10 horsepower you are looking for. I can see it being expensive initially, but once you have it figured out will it really be a repeatable exercise.

I have to disagree that a rod ratio change would not be worth going for. There is already an off the shelf rod available developed for the stroker. Do the upfront work to build a proper piston for it, and you have a combo that will not cost any more than the current rod and piston combos available, once the combo becomes popular enough.

A properly ported BP head will flow as well as say a stock B16 head, and they have a better rod ratio than a BP. It makes sense to me.

I am not suggesting you ditch your current combo, but the next step should be in this direction in my opinion.

Rover has a longtube 4-2-1 Stahl header built specifically to maximize low-end torque. Not sure if I'll ever get around to doing a back-to-back, though.

I'll be following this thread for sure!

Your point is noted.

We have BTDT. We have data on a long rod 1.9L BP. We have no plans for further experimenting with long rods for this program for the reason outlined previously in this thread.

I did not know they did 4-2-1 headers for the Miata.

I personally would use the 4-1 for this project.

In case it wasn't clear, my Maxim is in Irvine CA and I'll be in town for a couple days.


I know many people would love to see dyno results of the maxim regardless as it's a scarcity.

Current design?

I'm actually not entirely sure, I wasn't aware they made different designs, but it does match what is pictured on miataroadster. It's in great shape, just some minor superficial rust as is expected. I'm sure it's going to fit the bill if you guys wanted to fuck with it.

Snagged it for 550 shipped from Japanistan. So it isn't toooo un-afforadble anymore. :P

Is that new or used? I was under the impression it was like 1.5k new.

Used of course..

The guys that buy it new in japan only costs a hair under 1k USD. Especially given the extremely favorable exchange rate.

It's 1.5k to us round eyes in Amerika, jacked up shipping costs and only a few guys willing to stock the part gives them the "privilege" to increase it's price quite a lot. No wonder it's impractical to have in the states. Meanwhile, it isn't uncommon to find Miatas running around with a Maxim header in Japan. :D

Just goes to show the disparity in the valued product between here and there.

contact me through our website. Send me a couple of pictures of it. If it is the current design, it is relevant. I will buy a Maruha VP and run all three on the dyno.if andrew loans me his Stahll, I will run it at the same time too.

Done.


Looks like the Miata community is finally going to get dyno results of the Maxim as opposed to referencing the same damned thread on m.net as everyone else does. hahaha

For shits and giggles it'd be fun to throw an eBay header on there too. Prove once an for all they are junk.

I don't need to waste 4 hours of my life to prove that ebay headers are junk.

Test car will be our 95R project car with a CNC BP6D head and Tomei cams most likely.

Maxim Works NB header
https://www.miataturbo.net/attachmen...ine=1379175659

Maruha VP header.
The Maruha has an anti-reversion cone built into it's flex joint. Their testing shows some useful power gains with its addition. We'll find out.
https://www.miataturbo.net/attachmen...ine=1379175659

Racing Beat
https://www.miataturbo.net/attachmen...ine=1379175659

If I'm not using it, sure.

Interesting Thread, Subscribed

emilio what was the torque like when you dyno'ed 190+ hp