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1.9 wbx turbo, stroked for 2.1 turbo in a bug questions
bratjie - October 25th, 2015 at 10:20 PM

Hi guy's, here's hoping for some advice please. I have turbo'ed a 1.9 wbx turbo into my bug and she ran pretty well, then a few month's later I upgraded to 2.1 into the 1.9DG casing without any other major mods and found she ran a bit worse than the 1.9 engine. So I started over and got to thinking, previously she was a stock 1.9, single 36 Dellorto, charge cooler, and ran a small Ford Ranger junkyard Turbo. I have now changed to the spec's as below but have a concern about deck height, there isn't any! Can anyone help me make this baby go like a rocket?

First, all rotating components, rods and pistons were dynamically balanced and weighed. Kept the 1.9 rod's and bolts but with 2.1 crank and pistons.
Put a similar cam as tcs20, added 1.25:1 ratio rockers, racing single springs, valve job, heads ported and polished and straight cut cam gears.
Added 2 x 40 Dellorto's and a Hybrid T3 turbo, .48 ar turbine and .50 ar compressor.
Have rising rate fuel press regulator, external oil cooler and charge cooler.
Ignition std electronic (for now) locked at 24 deg,
I have 15cc piston combustion volume per piston and 46cc in the heads for each piston total - 61cc. This with no deck height gives me a CR of 9.8:1 which is way too high for turbo use.

Need some pointers where to lower CR, pistons or heads or both? Shave off the top of piston or mill out inside?
Don't want to shim as the rocker to valve stems (lashcaps on) geometry have been set and chromoly pushrods already cut to size.
Any info appreciated,
Hope to hear from you soon!


modnrod - October 25th, 2015 at 11:37 PM

http://www.gowesty.com/library_article.php?id=105 

Did you factor in the 1mm head gasket?
Using your specs I get 8.75:1. If you took 3cc out of the head by blending the chamber angles around the valves, and another 3cc out of the piston dish to give you 18cc, then I get to 8.12:1.


1303Steve - October 26th, 2015 at 02:22 PM

Hi

I had a 2.1 10.5:1 motor in my bug, I was running dual IDAs when it was high comp, I then bought some 9.0:1 2.1 piston and had the chamber in the piston crown taken out to give me 8.0:1 comp, I ran Autronic SMC injection on the motor then.

I was running Berg 1.4 rockers with a stock cam, It made 96 hp at the wheels with low comp and EFI, I never got a proper dyno reading with boost as I sold car

Steve

PS. maybe you need to fit 2.1 rods and psitons


bratjie - October 27th, 2015 at 03:48 AM

96 hp with boost? I made 110hp on a stock 1600cc with 1 dellorto, boosting 10psi, std ign, pressure regulator and charge cooler, some minor headwork with race springs and chromoly pushrods, made 130hp with stock 1.9 wbx boosting 14 psi,
Expect at least 180hp with the new 2.1 stroke, headwork and twin 40 dell's + brand new t3 hybrid turbo and cts 20 cam and 1.25:1 ratio rockers, I'm sure it's able to achieve?
Thx for your input,


1303Steve - October 27th, 2015 at 09:23 AM

96 was with low comp and EFI, no boost, Im now making 277 kW but have 3 extra cams now


bratjie - October 27th, 2015 at 03:25 PM

Wow, cant see your pic's though. Are you doing those figures with a wbx motor?


1303Steve - October 27th, 2015 at 04:00 PM

Im now running a EJ207 STI motor