Miata Turbo Forum - Boost cars, acquire cats. - VVT Head Porting for EFR build

- Engine Performance (https://www.miataturbo.net/engine-performance-56/)

- - VVT Head Porting for EFR build (https://www.miataturbo.net/engine-performance-56/vvt-head-porting-efr-build-72677/)

VVT Head Porting for EFR build

Please take a minute and look at the following pictures and share your thoughts as I assemble the head for my VVT EFR build. Lots more to come soon. I hope to put this head on the flow bench tomorrow and see what we really gained. Your thoughts are greatly appreciated.

The valves are Super Tech +1 SS. Springs are ST dual lights. Guides are SI. Seals ST Viton. Really thinking about custom ground cams in the future.....

http://https://lh4.googleusercontent...0/IMG_2713.JPG

WTF? Am I really that fuckin stupid? Why can I never get my pics to embed?
Someone please PM me the process. I have a lot of great pics and want to share!!!!

I have my pics hosted at picasaweb and copy the image url and paste it after clicking the image icon here. What am I doing wrong? I swear this is what I did last time and shit worked.

You've screwed up the copy paste. Let me fix that for you.

https://www.miataturbo.net/attachmen...ine=1368073966

yours looks like:

Code:

http://https//lh4.googleusercontent.com/-Z9MGlvnEbc4/UWeKfBfQWhI/AAAAAAAAY20/sFFyd-NFViQ/s720/IMG_2713.JPG

mine looks like:

Code:

https://lh4.googleusercontent.com/-Z9MGlvnEbc4/UWeKfBfQWhI/AAAAAAAAY20/sFFyd-NFViQ/s720/IMG_2713.JPG

Very important difference at the beginning of the copy-paste.

you doing that yourself with hand tools?

I am on my fifth Dremel! Lowes down here swaps them out for me under warranty

that's really impressive.

Thanks! But the truth is I had a local shop do the machining for me. I am simply doing my best to learn what works here and do that. I have built many engines but never a turbo or super high performance engine so I am leaving the heavy lifting to those with skills so to speak. I will of course do an out standing job assembling this bitch....lol.

I hope to post a build thread next week.....

So, how much power can an EFR6258 really make in our cars? Hmmmmm, I hope to answer that soon.

Was this your first time doing a port & polish? Any guides you referenced or anything you read that helped?

I didn't do the work. I did however read as much as possible and then I printed out a manual of what I wanted and brought it to a local shop that does a lot of short track race engines. I printed off the threads Dale (Bogus) posted and the whole write up Keagan did about the BP head. We tried to concentrate our efforts is the shape of the bowl and not the port. The long and short radii. When we opened the seats up for the bigger valves we had to touch up the bowl just a little. I took it to Race Engineering in Salisbury NC this morning and he was rather impressed that the guy who did it had never done a BP engine. Said great things about his work which made me feel good.....then he said my casting was shit to begin with and he could only do so much. We went over to the shelf where Bob (Owner of Race Engineering) had about 30 BP heads and he showed me how much of a variance there is in the castings. So I did what any of us would do, I bought his best casting and told him to do his best making that bitch flow as much as possible! I am interested to see how his head flows compared to this one. I know there is an art to this and each head design likes certain things better than others. I wanted to send my head to Keagan but the time and cost was too much for a street car. Remember, this is going in my wife's daily driver! She is very happy with a stock 02 VVT engine in her 94 Miata but I just about have her believing we NEED a VVT turbo in the 99 10AE. So being the good husband I am, I want to build the very best engine for my wife that I can. Hence, EFR/VVT/blah/blah/blah.....

Can you elaborate on what casting variations you where shown?

Just a wide range of casting quality all from the same castings. The variation of flashing and even the shape of the port and bowl varied greatly. Some heads had enough material to do a proper shaped bowl and some don't. Bogus told me that he often has to weld one port in particular for the way he shapes the bowl. I wonder if his head flows a lot better than what my local guys do?

Just as a note, a friend had a BP head done there for his FSP car. His thought on them was that they really knew the BP motor, but were very spec miata minded. That led to some misunderstandings on what could and couldn't be done for his class. He had to be very specific in what he wanted.

Yes they certainly know all the rules for SM. I was very clear that I have NO classing rules and I want to build the engine I want not one that fits in a certain category.

What valveguides are those? Bronze/manganese? Is there any point in going to the bulleted ones or do those don't show any benefit on these motors.