• RWD
  • 'Minty' The 240 Wagon

Loving this build thread mate.
How much can you get a disco potato for?
Samman88;56022 wroteAnd @GingerNinja I don't know the exact one he bought but pretty sure it was $200-400. And hopefully! I'll let you know when it doesn't fit haha! How do you tell?
If you can get the spark plugs in then you must have a new version. The old ones had the flange on the wrong way so you had to cut it off, flip it over and then weld it back on.

As for the turbo, I'd run the free 18T. I don't think you'll need much turbo with 10:1 compression.

Hey guys,

@YLD244 cheers! Your turbobricks thread has been an inspiration for many of my engine mods. I think the disco potato would be a pretty well suited turbo for my engine/power goals. Unfortunately the new Garrett Gt2860rs bb turbos are really pricey (like $1000+) and the used ones generally have sr20 tax put on them and are being sold for a reason - either broken and needed replacing or upsizing, in which case they wouldn't have had an easy life.
In all honesty I'm looking into a few holsets at the moment. It's just finding one locally that suits that is the trouble.

@GingerNinja thanks for the info! Spark plugs seem to fit so all good for now (lucky!)
7 days later
Progress? Going 18t? Pcv system thoughts? The yoshifab unit replacing the stock one is good but I barely have issues with heavy breathing with a big hose from the stock box to a catch can going to the stock intake position..
Nice build mate.
I wouldn't worry about the compression ratio being higher than the turbo b230 block. Whats the N/A block, 9.5?
With an aftermarket EMS you can always run it richer beyond a set load point so the evaporative cooling of the fuel cools the combustion chamber to prevent detonation.
Even configuring a switch for times when you want to beat the piss out of it, to allow a really large enrichment during deceleration spark cut. It will pop and bang and pour black smoke out the exhaust, but the pistons with love the cooling after they've felt heat generated by 20 pounds of boost.

Any reason why you won't run a factory b230 turbo type PCV system?


/Andy
Oh when I made my manifold I found that the cylinders 2 and 3 are spaced at 108mm and the outer ones are at 105mm
Looks to complicated to me, no need to touch the rocker cover at all unless the other two breathers prove it to be a hassle! Otherwise its a lot of work for basically a slightly more powerful than stock turbo build...

I had b230ft pistons and b230fb pistons. Both from squirter blocks next to each other the other day, identical. Unless the person I got the ft pistons from was lying.
Vee_Que;57613 wroteI had b230ft pistons and b230fb pistons. Both from squirter blocks next to each other the other day, identical. Unless the person I got the ft pistons from was lying.
Isn't there more dish in the top of the turbo piston for lower compression? 8.7:1 compared to 9.8:1

Came from a 95 b230ft/the low pressure turbo. As its been previously said the ring height is lower. But it could only be for earlier motors.
5 days later
Hey @Andy thanks! I've just got some larger injectors so will most likely do as you say untill I start running e85.
The only reason I'm not running a factory B230 PCV is because I don't have one and my intake piping is not stock.

Yep you are right for sure @Vee_Que I most likely won't make much more power than a stock b230 will at first and it is alot of work but I'm just upgrading bits at a time.
Basically just going to get her running then upgrade the next thing that is a restriction.

I'm not sure about the pistons that you have but apparently turbo pistons are dished providing lower compression and the rings sit lower (meaning you can mill more off them)

My idle will sound like a rotary now.
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1600cc
That's excessive for only 200hp! Sell them and buy 600cc ones! they will just chew fuel rather than make you power!

Mill the pistons? What? You deck blocks and heads...

The clean piston is from a 93' squirter non turbo, the dirty identical one is from a 95' b230ft lpt motor. Maybe they went to the one piston later, as the earlier b230 pistons are dimpled instead....
Yeah super excessive I know. But I got them really cheap and maybe I'll use them as secondary injectors in the future.

As for the pistons, yep, mill them down 2mm to get compression to 8.8:1 if they are N/A pistons or you can mill down turbo pistons more (because they have more height above rings) 3mm to get CR into the 7s. You could turn them down also...probably be the better way to do it.

http://forums.turbobricks.com/showthread.php?t=286614&page=2

As far as I'm aware they never increased the compression of turbo motors to that of N/A so pistons should have always been different. I could be wrong though Volvo did some weird things with substituting components into engines!
Later motors are lower c.R na too Iirc.

Reducing piston deck height is bad I think, tight squish has proven to be better for these motors.
Don't worry about knocking the compression down. LS guys run 18psi of boost with 10.7:1 compression ratios. Run a good fueling strategy to cool the chamber down and you'll be fine.

By milling the pistons down you will be effecting two things:
1). How effective the flame propergates across the combustion chamber at top dead centre. Ideally you want to concentrate the burn in an area as small as possible.

2). Having no squish around the edge of the piston crown will allow far more heat to effect the top piston ring. Once this expands and butts together you will tear the ring lands off your pistons.

If you are studying engineering then you will get access to the SAE digital library, we do and I use it all the time. Worth a look, plenty of knowledge stored there.

Those 1600s are old school and have a crap spray pattern, piss them off. Hunt around for the correct size for your desired power goals. EV14 style injectors are pretty damn good.
I'm not too worried about CR as now I have a proper manifold, plans for E85, large intercooler, wideband and aftermarket ems. What I said previously about turning down pistons was simply to explain what others were doing. I have no plans to personally do this.

I have access to it and have read some of the bibles on engine design and tuning whilst doing FSAE, pretty good introduction and useful to an extent but majority of info is pretty generic...but still applicable.

I'll be working with the Bosch indys for now. Yeah they're old school but so is my B230 so they should get on. Worst case I'll just use the Saab 350cc injectors untill I find some 600cc EV14 injectors like you say.

Thanks for the input though @Andy it is appreciated!
Andy;58012 wrote 2). Having no squish around the edge of the piston crown will allow far more heat to effect the top piston ring. Once this expands and butts together you will tear the ring lands off your pistons.
This is the biggest problem.

Taking material off the top of pistons is a cheap and dirty way to get HC. It is a false economy.
The link doesn't work but in all my years on tbricks I never saw people taking anything off pistons..