hey there guys i just finished my corse so now i have a job im buliding up my engine.
im buliding an A15 turbo it will be ####in sweet.
im guna have the head extensively ported and polished with a valve job mos likely oval valves or just huge ones not sure yet. what do you guys reckon. and double valve springs put in.
for the bottom end im gunna get some JE forged oversize pistons, floating gudgeon pins and some strong as con rods but not sure which type to get, any advice on that would be appreciated.
also im gunna put in either a 1 or 1.5mm copper head gasket to lower the compression ratio for the big amount of boost planned.
what type of turbo do you guys reckomend i know a garret or something like that would haul but cash is a little restircted when it comes to the turbo im thinking a standard turbo but of what i dont know, it will have to be large. i know that the rest of the engine will cost heaps but i have the cash for that already so its all good. also what size intercooler should i get and does the type of BOV matter other than the noise produced?
i will be running this with twin 40mm webbers which i already and most of the other parts as well except turbo etc. and the actual A15.
what kind of power will this engine make with say
10psi
15psi or
20 psi?

and i will upgrade the fuel system to cope with the blower.
thanks

im always interested in this turbo stuff, how do you plan to run it through the webers, are you gonna box em? seperate boxes, one big box?

im thinking one of the best places to get the turbo is off an s-14 silvia, the T-28 turbo and that the blow off valve is a very simple device really and it shouldn't matter which one you get unless some of them have a reputation for leaking air when closed
but ill leave that stuff upto the guys with experience

how much are you planning on spending and why stick with the a-series? is it gonna be a sleeper or a full mod beast? (can you tell which one i prefer )

I put some thought in to this project my self and I figured that for the cost of the set up you can have a ca18det for similar cost and it would be more reliable than an a15 turbo.
I went for a ride in a 1200 coupe with a injected turbod and intercooled a15 and the guy had put a lot of time into the project and I recon an ca18det would have creamed it. From what Ive read a standard ca18det in a 1200 will give you high 13's, my twin turbo a12 was getting 15.2 and I recon to go any harder you would have to start to spend some seroius money.

But I guess if you are after something different go for it..
Ill be watching

boxxing the carbs is most probably going to be two seperate with the same lenght piping from the turbo to each (spliting at the last possible moment).
i was thinking of going for the S14 silvia turbo and intercooler.
as for a mod beast no not really, more sleeper than any thing.
i know a CA18 would probably be more economic but hey you cant beat originality.

Hey cfwase,

are you going with suck-through or blow-through?

Since you are wanting to run twin carbs you may want to research the Lotus design in their Esprit Turbo. As far as I know they run twin Dellorto's with a totally sealed enclosure around the carbs.

Remember if your are pretty keen to get big kW that you cant intercool a suck thru system.

I reckon if you dont want a headache you should consider the CA18DET or SR20DET. Maybe you should get in contact with the bloke who turbo'd the A15 in that mag a while back, see one of the other threads for details.

I dont mean to discourage you, dare to be different, just aslong as you do the research is what i reckon.

I know guys who have messed with A series turbos for over 10 years and at one time they were cranking out 2-3 1200's turboed a week. I remember there backyard at one time had 14 1200's all waiting on the same treatment, These guys got me started on Dattos and turbos and I haven't looked back!
I myself am building an A15 turbo for my 1000 wagon!
The basic setup was as follows:
A- series engine
T3 off a nissan VG20 ( Twin wastegate one)
intercooler
electronic ignition
VL commodore fuel pump
Malpassi fuel regulator
Stock carbie ( modified )
The carbie was modified by resizing the jets
and pressurizing it for boost !
This means the float has to be solid so it doesn't collapse ( brass float is no good)
And the seals on the carbie have to be made better to withstand the boost supplied!
From my friends experiances and i have witnessed this, a stock a series will out perform a modified a series when turboed.
From my own experiances from being in a 1200 a15 turbo and racing a mates 1200 with a stock CA18DET I have seen a turbo a15 out perform a stock ca18det!
Even though my friends have shown me this I am still modifying my A15
Ported head,
double valve springs
larger exhast valves
turbo cam
decomped engine
electronic ignition
fuel injection
and so forth I am not saying mine will go anybetter but i am trying!

I don't see how you could say a CA18DET could be more reliable than a turbo a series if it was injected! ( maybe it is just your experiences with a carbie setup that make you feel this way!)

All this said and done I am only using an A series due to engineering requirements in NSW ( 1000 can only have upto a 1600 turbo engine in NSW without other requirements! and if i was going to put a 1.6 litre engine it would be late model and a Nissan engine and the cost of fitting a rearwheel drive gearbox out ways this option! atleast to me! )

But dude if you are keen I say go for it!

If you got any questions I am only to glad to help you out or aleast tell you what I have experienced with this kind of job!

( If you didnt realise their setup was blow through! Some might say boxing the carbie might be a better setup but I have not tried this setup so I can't comment! But from what I have seen from old factory American setups this could be a good way to go!)

CA18's and SR20's are the most common versions of these motors. But you could get a bit cunning and mix and match the various other versions to satisfy the registration requirements.

SR16, SR18's exist.
CA16's also exist. It is just about using the block to satisfy the 'Yes Officer it's a 1600cc' or whatever. I'm not 100% sure that this works, in regards to parts interchangability, but I think it might.

I'd like to see someone do that. You may be able to use the CA18DET or SR20DET head. It would mean getting one of each motor, and a strip down and rebuild. But if you're serious (like many of you A-series addicts) Then this shouldn't faze you.
The CA16DE block / CA18DET internals and head idea is cool, because you can use the CA16DE exhaust cam for more power.

You may also need to look at engine mount points, as the CA16DE, came out in the first Aussie N13 EXAs which are FWD and may have different engine mount bracket holes on the block.
Enough going on. Having a powerful A-series has it's benefits. I saw a fella recently with 74kW at the wheels out of an A15 with a single DCOE weber, in a Datsun 1000 coupe. It went pretty cool. But not even within comparison of Andrew's CA18DET 1200 coupe, especially down the straight at Oran Park..

Chris

Hey dude I have nothing against turboing an a-series, go for it. What I mean by reliability is that the CA/SR was built to handle forced induction. The old a series even if you built it from scratch would not be purpose built for forced induction. The block is 30 years old even after a freshen up. Plus the CA/SR have more bolt on accesories unlike the a-series where almost everything will have to me custom made. If the budget can alow for that, go for it.

Its like these people who want to chuck on turbos to the originally NA CA18 or SR20's. Yes its kind of the same motor (same series) but the turbo blocks have been built to with stand the forced induction.

I have seen some examples of carby turbo setups and sure they work. But for an ease of installation, setup and running point of view I dont think you can go past EFI. You have more control over your fuel delivery, spark advance, etc etc with an after market computer.

Ok, so they have chosen a blow thru setup. What is the setup that factory old american cars use?

I think one of the hard parts of this setup (but obviously it can be done) is to seal the carby and the carb body. Thats why I said looking at the Lotus for ideas as they must have THE most successful blow thru turbo design using twin carbs. This is factory stuff, why didnt they choose injection, I dont know.

Please give anything a go, just do the research (good or bad) and see what fits your budget etc.

Chris I understand what you are saying about building a smaller engine with bigger internals ( the engineer said he would be happy with this if he doesn't know as it is what is visable that counts)
I even viewed this as an option but when you start pulling down 2 or more engines to build one the money starts to add up!
But if ppl have got the money I say go for it as I too would like to see this done!

As for the other bloke( i think mr_nizmo4)
if you want to build an engine with all bolt on accesories and not be different i say go for it! But if you start adding aftermarket computers this will still bring up the cost!

As for a series not being up for it i have never seen one brake a block or rods or even crank! I have seen them spit head gaskets out the side! ( so o-ring it) and I have seen boost blow out the gaskets on the carbie and spray fuel out this causeing the engine to lean out and crack the rings because they got to hot!( so box the carbie to fix this or pressurise the carbie to take boost, we glued the carbies together with fuel proof glue we even tried fuel proof rubber for the carbi gaskets and this stood up to the job!)
If you want fuel injection make it or get a factory a series efi manifold!
If this is done ( as i am doing ) with a aftermarket computer it can be tuned to run with no problems!

Might i say we have run up to 32 psi boost with the carbie setup with no problems!
But like any engine sustained high boost will cause heat and even a factory turbo with bolt on accesories can't with stand this!

Like I said I don't claim this to be the best engine but there is no way you can say any other is better stength wise! unless you are talking 3 main cap A10 engines! these would just be asking for trouble!