autopaul

i know essentially what engine dowelling is, ive done my homework on the search and am planning on building a 12at, but for the life of me i cant figure out what engine doweling is, and why its so expensive, other than that it is the reinforcement of the engine dowell pins...

can i do engine doweling myself, what would i need, i want some professional opinion here, ive been reading about different aspecets of making a 12a run realiabley with boost, and i found this would be very neccisary any help is great

TurboSE

Well i dont think U will need it.Unless ur goin Crazy W/ Your setup
Just IMO

PaulFitzwarryne

If you intend to go over 300hp additional dowelling should be considered, above 400hp it is essential with a minimum of 6 extra dowels.. Only an experienced fully equiped workshop should do it, and the cost is minor compared with an engine rebuild.

I suggest you look at Wackyracers recent excellent thread on problems with adding a turbo to a 12A and going for high boost. I have a 12A T with the low compression rotors but limit it to under 10psi just to keep the engine intact. If you use the 12A to get highpower dowelling is critical.

WackyRotary

Actually its Wackyrotary, not racer! But since you use low compression rotors, and keep it under 10psi, what is the boost number ya think to aim for with n/a rotors with no additional bracing out of curiousity?

luiml73

iTrader: (1)

http://www.nopistons.com/forums/inde...44016&hl=dowel

read this

https://www.rx7club.com/showthread.p...ight=dowelling

DAVID GRIMES

It's like pinning the housings and endplates together to prohibit twist.

Like what if your commode seat wasn't "pinned" to the toilet base ?

PaulFitzwarryne

Sorry after all this time reading your posts I should have got your name right!

I spoke to Hitman before going turbo and used his advice for 10psi for my low compression rotors and a mega FMIC. I am considering adding two more injectors but going down a size from the existing 800s. I could go higher but the additional performance would not be used and I would have to use higher octane fuel at 10% more cost.

The critical factors in deciding maximum boost for any given use are the size of your IC and the injector capacity. Without changes to a stock 12A, going above 8psi long term is going to be a problem. If you want maximum short term performance then I would be looking at around 12psi without dowelling.

In contrast, for a daily performance 12A driver using an aftermarket turbo on a NA without an IC, I suggest 6-7psi would give you improved performance, longlife and reasonable fuel consumption. But not so much fun ! The official factory levels with low compression rotors for both the 12a T and 13B T are very conservative but in reality boost seems to climb 10% above specification anyway.

Most of the hot RX-3s I know port, 6 or 8 dowel and go megaturbo with 15+psi using two extra injectors and a FMIC. But then they seem to spend just as much time rebuilding as on the track! Here the hot RX-7s mainly go 13B T as its cheap to get a half cut, while a drive in drive out conversion with a rebuilt engine costs US$6000 with up to $12,000 for a 10.5-11 second 1/4 time package.

What boost are you using?

WackyRotary

I am using 8psi and a FMIC. I do however need to route the air filter away from the engine, it does pick up a little heat air there, not such a good thing...