If heat loads are a concern you could consider water injection. Roughly the same flow as the fuel. Might be worth an exhaust temp guage? That would give you an indication of the heat loads I woud think. I read a paper a while back on how effective water injection is at reducing heat loads on engines. Could dig it up if you're interested.

Mike, I burst out laughing when I saw you buy someone elses twin turbo A series project and I enjoyed reading about it. Although most datto owners are budget conscious, in reality most working class blokes are with most hobbies. In this case just pointing out the guy has other commitments and this is an intermediate setup towards his bigger picture as hes stated in previous posts.

Its quite easy to just blurb out do this and that but for some skinning a cat like everyone else does is not a challenge worth entertaining. Unconventional twin cam boosted A series that makes power from 5-10k bring it on!!!

As for the long stroke in a taller block, the rod stroke ratio will be improved. Most speedway and long time A series gurus swear by it, especially at such dizzy rpm.

Nice work Simon. Bet those figures put a beaming smile across your face.

A pretty complex and unconventional setup [from what I've gathered] that is well worthy of those figures seeing the amount of time and effort you've put into it. I'm still spewing I didn't get to see it when it was here in SA.

Hats off to you sir!

thats a pretty sweet power figure you must be happy, be good to see some snap shots

call me the devils advocate, asking the questions to see what you have and haven't thought about.. of course sikyne has the reputation for being very calculated so i expected validated answers

so whats the plan for boost, 14psi is surely achievable with a smaller turbo, but maybe your chasing more boost. the twin cam ain't gonna make any more exhaust to get the turbo spinning up any different. although will this taller block a12 have more capacity? surely your not going to increase capcity and go over the 2ltr class with the 1.7 multiplier?

my theory was always to go for a low reving turbo a to reduce the stresses... high revs and forced induction is counter reliability in my mind

what sort of compression ratio are you looking at?

with power between 5 and 10k, how are you going to keep the drive line in-tact on launches?

is it realistic to keep the revs above 5000rpm on the track? diff selection would be pretty important, i wouldnt think you would be wanting to get down to second gear to keep the revs up in tight corners as you will be frying the tyres on the exit

D - i dunno why you are airing his life story, not many people with money to spare build dattos

Gotta take a video of the little aseries yelling in pain! :) but good power

My old r100 12a monster bp didn make any power till after 5.5K :}
Hes doing what he can with what he has on a budget, extra child coming,
new old house to sink money into, full time job, custom from scratch
dyno project to finish, workshop in different town and still probably
has the most powerful virtually internally stock A12 in the world.
At this rate the twin cam A12 with longer rods taller block and better
manifolding with e85 is probably looking at over 300hp atw considering
400+hp is not rare now in boosted cbr1000xx on the draf strip.

thats some cracking power simon!
you must have great power to weight for your class!

wheres round 1 held?
how is ipra run? qualify then race?

good luck!
i hope it all holds together for you..

Its a circuit racing engine. The turbo was selected for the twin cam conversion motor that is designed to work between 5000 and 10,000 rpm. I didnt want to spend another $1,300 to go a touch smaller for this engine.
Its good on the track all the same. I put better cam in it to get me a bit more top end.
Should work well between 4500 and 7500.
I certainly wouldnt say the turbo selection is terrible!

The engine is in a car, Im racing this weekend, Round 1 of the Vic IPRA series. So definatly not a run until she blows engine. I hope to be able to drive it back on the trailer Sun.

boost at 4800........ that is some terrible turbo selection right there

well done getting big power but you arnt building a drag car, power coming on at 4800 is terrible

forget tunning and stuff, swap the turbo for a smaller one

get more power under the curve rather than outright top power

[edit] im making the assumption you want this in your car... maybe you dont intend to use it though?. is it in a car now? is this for track use? or is it a lets see how far we can push it till it blows?