When do you need to move to forged pistons and steel rods??

Can i straighten a few things out.

i know that for ultimate power there are engines which are way better to start with, than a x flow 8v. It will be a toy so is not going to see daily use, or the kids in the back seat (wont have one), its for weekend fun and track use, hence the reason im leaning towards balls out.

I have spent a reasonable amount of time thinking about the engine for my next project, and everytime i come back to the image VR6Will' xflow (which i now cant find!!)

I hope you guys can appreciate that we all have our own ideas, and goals for our cars, this is part of mine.

the ultimate goal is to have something that looks like...... nah thats another thread.

Gary, my blue car is nothing but a parts bin for this project!

Jason, i appreciate your comments on budget, its true i do not have limitless funds, so i anticipate a conflict between the goal and the hence why im not aiming higher, i would love to go chasing after Tony's 220bhp but im fairly certain the budget wont go that far.

Smudge, plenum design is still in my mind, i have been looking at BTCC type equipment.

Eddie, its not a mythbuster project, just something i need to get out of my system, like a mid life crisis Harley.

 

any way back to the OP, looks like for safety, Rods and Pistons are needed.

any tips on where from?? Intergrated engineering look good.

 

Ok. So you want a road car with some fuel economy, idle quality and drivability and the occasional track car with good engine response, a good spread of torque and durability.

A stock ABF engine, as shown many times on here, can fulfil most of that brief with very little cost as would a std 1.8T with very little huff, but the engine must be an 8v...

So my suggestions based on what you have just stated are:

Target 165-170bhp@6000rpm and 155-158lbfft@ 3700-4600rpm, Redline-7200rpm

FDR 3.89
2.0 2E/ADY/AGG lower engine.
MLS gasket
11.5-12:0 CR pistons.
288 hyd cam
Fettled 'ABA' crossflow cylinder head
42-45mm ITBs.
Bora/Beetle 4-2-1 headers
Custom enlarged downpipe
2.5" Jetex cold end.
Engine calibration.

At this level rods are not required as you revs and cylinder pressure are still similar to a factory ABF motor.

The above combination, based on what I have seen over the years IMO will make for an extremely strong pulling 8v motor, have 2.0 16v rivalling performance and not really break the bank.

This is what I hoped your old 2.1 8v would have come close to achieving.

Regards.

 

Whatever you do, buy with care.

There seems to be a lot of junk rods floating around that are all much the same - being made in the east that each vendor takes and stamps with there own brand. Im sure in SOME cases the oem rods are actually better than SOME of these.

At this stage I think to save all the hassle of sifting through god knows what Id just by carrillo rods. But they are not cheap.

Brian,

 

Funny you should mention 'vr6will' I was going to use his story as an example too.

It's a while ago now but for whatever reason that engine didn't deliver the goods he had high hopes for, was on Jenveys/DTA IIRC?

He soon ditched it for a boat anchor, then 'mit turbo'

At the end of the day Alan, it's your project and you do as you please mate.

 

Anyway, some 8v Xflow 'mit drosselklappe' inspiration.

 

Wasn't danster building some crazy 8v with abf rods or pistons or something along those lines? He had weighed them and everything iirc

 

A 320 cam'd 42mm inlet grunter it is then Alan! lol

Std rods should still cut it Alan....even with a big cam you wont need to rev it past 7,750.

I know an engine builder who used to do some VW cup engines a few years ago...std rods are a must, or were then. His customer used to be a touch harsh to say the least...they would come back with spun bearings and 10k+ on the tell tale in the ecu from over aggressive down changing...stretched the big ends but never broke a rod.

I do like the shorter stroke 1800 crank for rpm....make a great 1900 base and make 190+ with ease all the way to 8,500 (with steel rods if using the revs regularly), with peak in the mid to high 7's. I'd also consider a short f/d @ 4.25 or 4.47...it'll still pull 125-130 in 5th.

 

Above GS6 : 316 degrees. Bog all low down, but modern calibration will help no end.
Toyotec: your figures (if you will excuse me) make it all sound so easy, In my humble experience its never that straight forward, unless you throw development time at it.
Good thread, keep it coming
Jon

 

You are absolutely correct. It is never straight forward indeed. It would take lots of development time to achieve such a result from an 8v.
I am under no illusion. Plus the transients and part load driveway and response will take lots of road hours to get right. This is why I suggested a tamer camshaft based on requirements. Perhaps a compromise in cam duration to a tad bigger that what I suggested and a tad smaller to what Jason suggested maybe.

 

Ditto on the 1.8 crank, great to get into the sweet zone faster.