valve sizes for 300bhp 2.1 turbo?

marco the steem engine · Mon Oct 08, 2001 3:47 pm

what valve size should I run? the biggest i can run is 44/37 or 43/38 or 42/39 or 41/40
which should I go for and how much boost should I run with what static compression to get 300/350bhp?
I'v got EFI and will be intercooled and 97oct fuel.
as no one I speek to can give me a definet answer!

PapaG · Post by **PapaG** » Tue Oct 09, 2001 3:07 pm

In most cases you would want the larger valves as big as possible on the intake side. I am far from being a turbo expert but it seems from all that I have seen Low static commpresion and high boost. 7.5-8.5 static compression and 15-30 psi boost. Intercooler a must. Are you running the Wasserboxer Difigant ECU or aftermarket. I would think a TecII or Halteck would be needed to control timing, fuel and boost.
Not many people running boost on a WBX engine. Good rods, and pistons a must for reliable engine, head studs-bolts too.
As the valve size you could chose the middle of the road.
2 cents + change

[This message has been edited by PapaG (edited 10-09-2001).]

Bobtail · Post by **Bobtail** » Wed Oct 10, 2001 6:04 am

Marco,Just go for the biggest..............
Oh I see you dilemma!
Go for the 43/38 after all you've got to get it in before you can get it out! If you see my point.
What heads are you running?

------------------
www.centralvwaudi.com

marco the steem engine · Wed Oct 10, 2001 1:14 pm

I'll be using a wisco 94mm forged piston and short carillo rod, 1.65 rod ratio and 220,000psi stainless steel head studs, in my waterboxer with 8-1 comp.
what do you think?

PapaG · Post by **PapaG** » Wed Oct 10, 2001 3:27 pm

Sounds like a good combo. I will be getting my waterboxer 2.1 at the end of October. I am not sure but I think I run it NA for a while to work out any bugs, then turbo it.
Keep us up to date on your project. I am going to try the VW FI at first.

Steve Arndt · Post by **Steve Arndt** » Wed Oct 10, 2001 5:15 pm

Tell us about the Wiseco wasser pistons please!!!! Do they have Heron chambers measuring the same as stock? Lower wrist pin height to lower the CR? What gives?

I say go with whatever can be installed most easily. You probably won't feel the change anyway (between the listed combos that is), it is in the valve job and the port, not the size of the seat!

Are you using Porsche or VW length rods? 5.352 or 5.394" 22mm wrist pins? I'm asking because I'm going to do this conversion myself, and also I'm trying out some special heron'esque chambers in the old aircooled heads!

Steve

[This message has been edited by Steve Arndt (edited 10-10-2001).]

marco the steem engine · Thu Oct 11, 2001 1:38 pm

Hi Steve,
the wiseco piston is the sliper skirt 94mm(air cooled piston), nothing too special but 22mm pins and a low wrist pin height, very light weight and avalible with notches for the valves.
I'm going to get the compresion 7 or 8-1 with custom length rods, as the shortest rod you could Theroeticaly use is 4.937 on 76mm stroke, I'll be making an ajustable rod for mesuring perposes to see what is feasable.
What stopping your engine making more power steve? 126bhp is great but surely it should be nearer the 150 mark at the wheels, mabe 200 at the flywheel look at the saab 2.3 turbo for example 215bhp at the flywheel and what other problems have you had. just curous as I'll bedooing the turbo thing soon.

Steve Arndt · Post by **Steve Arndt** » Fri Oct 12, 2001 4:44 pm

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by marco the steem engine:
<B>Hi Steve
What stopping your engine making more power steve? 126bhp is great but surely it should be nearer the 150 mark at the wheels, mabe 200 at the flywheel look at the saab 2.3 turbo for example 215bhp at the flywheel and what other problems have you had. just curous as I'll bedooing the turbo thing soon.</B><HR></BLOCKQUOTE>

Huh? I can't find the post mentioning 126 horsepower? Did someone else type that? My current combo is a daily driver 9.4:1 rather wild 2276 Type 1 outputting around 170 horsepower.

I have concerns about using flat top pistons with the wasser head designed for Heron chambers. The area around the edge of the stock piston that borders the "dish" is there to provide squish against the matching flat area on the head. You are going to have a bunch of deck height to get the CR as low as you want. Lots of deck and reduced squish lead to detonation. I really would like to know how it works out in the end both during assembly (should not be any problems) and on the road results. I'm considering buying The Wiseco 94s and milling my own mini-Heron chambers for fun. Keep us posted.
Steve

[This message has been edited by Steve Arndt (edited 10-12-2001).]

Steve C · Post by **Steve C** » Sat Oct 13, 2001 9:07 am

[QUOTE]Originally posted by Steve Arndt:

Huh? I can't find the post mentioning 126 horsepower? Did someone else type that? [QUOTE]

Hi Marco & Steve
I sent Marco an email off the forum and Marco must have got us confused, I know I get confused sometimes with who is doing what. The 126 at the wheels with 9 psi was achived with injectors that were to small, as soon as this was discovered all tuning virtually stopped. Im sourcing bigger injectors now and doing a lot of research, I dont want to get it wrong again. Im sure it will run some better numbers with 15 psi. Im pretty impressed with it now, the power & torque are awsome, the way it still continues to accelerate at 160 kph + is amazing, the quietness of the motor is very nice. One downside has been my turbo oil return, I went with 1/2 inch hose and have been getting a bit of an oil leak around the housing so I will fit a bigger return hose next week. Im doing two major things at once on my car, getting the turbo sorted and getting my 944 traling arms and brakes on the rear. I need the 944 bits so that my car can be legally used on the road, its a long story. Im using 9 x 17 rear wheels, too wide for the engineer to pass with VW suspension but with Porsche suspension I can use whatever was an option on that car, ie 9 inch wheels.
Just getting back to the subject, one of my mentors reckons the stock WBX piston would be good for 20 psi boost.

Regards Steve C

marco the steem engine · Sat Oct 13, 2001 6:42 pm

Hi Steve C
Sorry ! got all Mixed up!
Have a look at www.wolfems.com.au Theres a page for Injectors size I used the saab 2.3 turbo one's and seem to be good 50bhp'ish each, If you can find a set of standard Ford Cosworth Escort Injectors there good for 85bhp each that's the ones Im looking for now in the breakers.
thanks steve

Steve C · Post by **Steve C** » Sun Oct 14, 2001 9:07 am

Hi Marco

Ford Cosworths are pretty thin on the ground down here so I dont think I will find any of those. I friend of mine has given me some Merc ones pn # 0280 150 036, they are rated at 380 cc and 76 hp each so they might do the trick. Im still trying to get some info on the injectors that Im using, VW TLE injectors, so I can do some maths to figue if the Merc ones will do.

Regards Steve C

moggy · Post by **moggy** » Sun Oct 14, 2001 11:59 am

Hi guys

I had the same probs with injector size for my blown 2.4litre motor, but Andy E suggested (and sorted me out) with dual injectors, i.e. 2 smaller injectors per cylinder. With 2 injectors there's no probs with low flow and good atomisation and no probs with high volume.

Just a thought.

Andy E - if you're reading this, I've sorted myself out a 68mm throttle body of a Jag (with integral TPS) from a scrappy, so don't bother with the Rover one. Thanks anyway, speak to you soon re fuel pressure return line questions..

tdirs · Post by **tdirs** » Sun Oct 14, 2001 2:49 pm

I dont think valve sizes are much of an issue,cos the hp is largly going to be dependant on boost pressure,you wont be able to run big pressure due to 2 things,1)spark plug position is poor on a t4 you will get lots of detonation.2)cylinder head joint will blow,copper head gaskets work well but a ridge on the top of the bore will be better

marco the steem engine · Mon Oct 15, 2001 2:46 am

the engine is a t25 waterboxer, the spark is in the middle(like T1) and the cylinder head joint was over enginered by vw because if it was to blow it whould over presurise the water system. the barral's are turbo worthy 6mm thick all the way!

tdirs · Post by **tdirs** » Mon Oct 15, 2001 4:09 pm

Sorry thought you were on t4.I'd go for bigger exhaust valves by a couple of mm if you can get away with it,but dont under cam it.We run a turbo t4 with 11.5 mm lift and thats just over [email protected] bar boost