Interesting to see that you got the same wavy surface on the retainers as I got (so the quality seems to be consistent).

I've rejected the ST retainers due to poor fit on the springs and the 15-20 hours inspection intervals (they failed catastrophically due to wear after 30 race hours in a BMW head).
I'll use retainers in billet steel instead (much better wear resistance and custom made to snap-fit the springs).

https://www.miataturbo.net/attachmen...ine=1344986203

Some deets on the actual build process. No joke, Keegan assembles and disassembles the engine at least three times before building it for real. It's really something to behold.

1997 Mazda MX-5 Miata: Assembly By Keegan Engineering, Pt. I

Can Keegan make a miata head flow well enough to hit 700hp at something other than 60psi?

fae, stop right there.

Serious question actually. I love JKav and I would trust him with my frozen embryos and this thread makes me feel stupid and that's a good thing.

My question is really, has Keegan built any miata heads specifically for boost?

I will give him a call, but I am asking for anectotes first.

Post back with what you find out if you don't mind! I have an engine I will be building later this year and am debating sending the head off to him for a little love. The '99 head I will be using already has oversized FM valvles and some of intergral's old 272 cams. (its for a rotrex build.. shh don't tell no ones!)

Remember when NA builds didn't make sense so we all built turbo Miatas? Well, it looks like those days are over.

Nah, time have just evolved so a Turbo build should now only be done on built engine and should deliver 350+whp. If not, whats the point :D

If everything goes the right way (and then some) I'll have my engine in three weeks (or it will be yet another race with the trusted old 70+ race engine).

I still don't see the point in N/A builds unless track car

Good question, I'm really not sure of the answer as it pertains to Miatas specifically but I never asked. I do know that at Cosworth he used to port the IRL heads and built their ChampCar engines back in the boosted days. Suggest dropping him a line.

This will be turbo.

JKav,

Great project, been following the car since it started on Insideline and saw it out at Buttonwillow with Kurt driving it a few months ago.

You should have the car out at Buttonwillow again next month at the Speedventures weekend (09/22 - 09/23). Miata Challenge will be there and it's going to be a ton of fun. Would love to see you guys running it.

Anyways, keep it coming.

Thanks comradefks. In that case...

http://blogs.insideline.com/roadtest...ting-rods.html

edit: seems our site is having some issues right now... try the link later.