8v 2l Twin Charged -my Little Project

[Duk]

On the subject of using stainless steel for making turbo manifolds. For anybody who has heard of 6Boost manifolds here in Oz (typically for Japanese cars), he haunts 1 of the other forums I belong too, does some excellent work and is very direct. Stainless looks nice, weighs less but costs a packet and inveriably cracks. Even the big brand name Japanese stuff like HKS and Trust crack after a few years. It's even more of a problem on engines that vibrate alot (Nord ).

[Storm_X]

hay thanks for the tips anyway guys

[buzzed]

Hi guys,

Never fear, I'm in it for the long run, just got a lot on the plate at the moment with work/house etc, but the project is most certainly ticking along.

For people following along, and starting to get confused about what I plan to do (I know I am am!): I am building 2 motors, the first one, being assembled now by myself and a friend is a 2l block, 2l single spark head, stock standard bore liners with oring groove, flat top twin spark pistons, stock rods, tidied up head (stock sized valves ports etc) with 10548 cams. Intake is camira, computer is camira JE, turbo is Garret T3, manifold is oringal Alfa GTV turbo part, supercharger is SC14. Intercooler is custom and will charge cool the first stage, second stage will be high pressure water/meth injected. Turbo will feed supercharger inlet. It is likely that the Turbo will be changed during this process of ussing out the system, but its the turbo I have on the bench, so we shall see how it goes.

I decided to build a 'basic' motor to prove out the concept without the fear of breaking things (read-wallet crippeling induced fear!).

The second engine will have carrillo rods and JE pistons (see attached, I got them today), Vin sharpe monoliner, MB (thats me :-) crank girdle, and a few other tweaks. Suffice to say, I don't really want to break any of this gear!

I feel that 300 engine hp should be achievable from the first setup at about 18psi. The second setup should be capable of 400 engine hp on pump fuel. When I say capable I mean reliable....I guess I'll find that out in due course!.

This is the plan as it stands...gotta have a plan right? It changes often, but the same goal remains, build an Alfa 8v single spark motor with twin charging.

Update on the first engine build is that Vin Sharpe has kindly found me two suitable sleeves to replace the shoddy ones I had, Thanks Vin! I am re-machining the oring grooves Thursday night, and then I'll be back on track for measuring and dummy fitting parts.

Enjoy the photos of build 2's parts, which have finally arrived. As is so often the case, builds take forever because we end up waiting for parts to arrive, so I wanted to get the ball rolling on that front. Also, it's not so painfull cost wise if I do it a bit at a time. I could not be happier with Jim Steck and the team as the parts arrived unscathed and are impressive to say the least, the americans make an ugly car or ten, but they make a great looking piston ;-).

[Biba69]

buzzed, I'm glad to hear Jim Steck is working with you on your project. Did he supply all of the above parts?

I'm curious as to what the two coatings are on the pistons. The tops look as if some form of copper was used, but doubt it. Were they custom made just for this project?

Aren't Carrillo rods lovely? And, yes, the US does try hard when it comes to making unattractive cars. I bought a set of Carrillo rods for a client's 750 engine - after the fact. After I rebuilt it, I began hearing of rod failures on the 1300's. Since early in its life the block had been bored out to 1500 cc, so I convinced the client we shouldn't risk it.

It sounds as if engine #1 (300) is being mostly assembled from 'off-the-shelf' parts - off your shelves that is - but is a great idea to test out your basic theories. But wouldn't you be pizzed if it turns out the test mule puts out more HP than the 400? I would be inclined to doubt that happening though.

Biba

[Duk]

Quote:

Originally Posted by buzzed computer is camira JE,

[braddo]

Um, when you say camira JE, are you talking about the Holden Camira?!!

Brad

[Duk]

That he is

[buzzed]

Yep I'm talking about Holden JE Camira.

If my test mule made more than 400hp I would not be dissapointed ;-)...then again the pile of bottom end bits on the floor may dissapoint. The bearing caps look very underdone at these hp levels. The base engine wont be run on big boost, and I've done my numbers so I know what hp to expect. I'll probably come back and tell you it made stuff all hp heh heh.

I'll tune it myself probably, but I beleive DR DRIFT in Melbourne is capable of doing this also.

[buzzed]

On sorry Biba, to answer your question, the piston tops are ceramic...keeps the heat in the chamber....equates to more hp...not sure what pecentage but hey, it's in the right direction ;-)

[buzzed]

just got back from mates place, new sleeves now machined to accept wire.

Anyone on here know whewre to get the wire to o-ring the sleeves? I know the dimensions but not where to get it from.

[batman]

We used to wire the liners on the Andy Rouse RS500 Cosworth engines in the eighties, in the end we got 550bhp out of those two liter Ford turbo motors, 18 gauge piano wire comes to mind, you need 5 to 7 thou above the liner to get a good seal into the firering.

[ae25]

hey nice project! good to see you're keeping it looking semi original

just read thru the lot.. looking forward to the outcome!
one point that doesn't seem to be mentioned.. is the difference in efficiencies between supercharger and turbo?
here you guys have been talking about valve overlap and the benefit of supercharging and beneficial pressure ratios between intake and exhaust etc. (reduce overlap and chuck a big turbo on haha).
I'd always understood that the turbo, even tho it created pressure on the exhaust side, was more efficient than the super charger due to them taking away power via the belt, (parasitic drag?). so although the turbo has a worse pressure ratio across the valves (which not so good for a complete burn), it was still more efficient in creating power.
therefore wouldn't the arguement of the compound system being better than a sequential system be invalid? does this give the bypass valve some credit?? (as most of the manufacturers have used in the past, including the nissan march ST, VW tsi, hks 4agze).
if this were true, then would it also suggest the words from the G.E. man are geared specifically towards superchargers that benefit under valve overlap conditions, whereas on turbo systems you'd use less overlap to overcome the higher exhaust pressure?
feel free to disagree

oh and the Delta S4 diagram.. i had always read it as having a bypass around the S/C once turbo was outflowing it.. but looking at the arrow directions on the valve, it could suggest it just be a recirculating valve used when off throttle. BUT instead of directing air back before the turbo like the BOV does.. it to recirculate air back before the S/C like a toyota SC14 1GGZE system.

heres a bigger pic found on carsfromitaly.com
and an idea id previously sketched which would probably describe your own system but without the bypass

[Greg Gordon]

I don't really feel like going into the supercharger vs turbocharger discussion again. That's been covered over and over on this forum in other threads, and it's way too complex an issue for any blanket statement about one being better than another to be even remotely valid.

The diagram I posted earlier for the Delta S4 is correct. I am not saying they never bypass around the supercharger, but it's certainly not the more common way to do it.

The words from G.E. were specifically geared towards supercharged and compound systems. Remember they built tens of thousands of compound systems and they never bypassed around the supercharger. They had the supercharger in place because a compound turbo and supercharged engine made more power than a turbo or sequential turbo system. These were engines with constant speed props and the turbos were almost always on boost in cruise and in combat so lag wasn't an issue.


Greg Gordon,
hiperformancestore.com

[gtv27]

nice picture of the turbosupercharged aero engine

presume that is circa WW2 or thereabouts - there's not much that is genuinely new in the world

[buzzed]

Batman, thanks for the tip, I'll suss it out. How to 'gauges' relate to mm's do you know? Maybe they don't and I just have to go to the music shop armed with my calipers :-). I was planning on 10 thou protrusion, so I guess I am in the ballpark. The Ford motor is in my opinion an incredible motor and 550hp hp for me will be a 'dream', 8V instead of 16v is the big difference, they had variable exhasut cam also? What boost did those suckers make 550hp? 30psi? Was it on street fuel? They were impressive at Mnt Panorama...wich that variety still existed....

ae25 Glad you like the project, I think it will be a great project myself and am happy with the progress so far. The interest it is generating is also great as that's half the fun, chewing over ideas with fellow car nuts.

I partially agree with Greg in that the turbo vs supercharger is a massive topic to do justice. I think it would suffice to say that each have their pros and their cons. As for efficieny, we can't really talk about efficiency without talking about a specific mass flow, as the efficiencies vary wildly for differnet operating points. Planes are indeed very different from cars when it comes to operating points. Cars are all over the effic map, planes can be nicely tuned to sit in a particular island of the map all day.

To me the plan is clear, I want 400 reliable hp, and I don't want the associated lag, but I love turbos and so one has to be on my Alfa. So to get rid of lag I choose a supercharger, an old one, and hey there are better ones out there, but not at 300 dollars there arn't! I had originally decided to switch the supercharger on and off once the turbo had reached a certain psi, but, after listening to people on this forum I have been convinced to just run the supercharger all the time, but at a low boost (with the aim to not spin it hard and hence stay in a reasonble efficiency island). This combination will be a good starting point I think.

The back pressure a turbo supplies at the exhuast is dependant upon mass flow and turbine sizing I guess. Bigger turbine =more lag=less back pressure. My thinking is, the supercharger will allow me to get a little more creative with the turbo sizing as lag becomes less of an issue in my mind. This is my next step, to choose the turbo. In a series setup as this will be, it needs to supply all the mass flow,but at about 15psi, not the 25psi the engine sees. My thinking is that is I size the turbo based on 15psi and total mass flow at 400 engine hp, then this should give me a turbo that will do the job. I also plan to use a size larger on the turbine side than I normally would, based on my interest in less backpressure and limited concern for lag. I wont go crazy on this front because I still care about transient response and the way in which the boost ramps...I also need to be carefull that there is enough available work in the exhaust gass's to spool it appropriately. For this I'll treat the engine as a larger displacement engine based on the boos the supercharger runs, I'll then use this as the mass flow and comapre it with the garett roller bearing maps available.

SO what do people think, holes in my argument? Heading in the right direction? Don't care, just want to see me break something :-)?!