Hi, i have question... i know there is lot of info but i cant find what i exactly need to know 

I want to swap 3f polo gt engine 55kw to my Trabant 1.1 with eaton m45. maybe with pressure about 0,6-0,8b 
Also with intercooler,blow off, programing Ecu - piggy back ecu,,exhaust manifold 4-2-1, ail fuel ratio gauge and more... 
My friend told me that its almost same engine like g40 but with not machined/drilled pistons because of compression and little bit different valves at head, the intake manifold is little bit better because of bigger holes? 
But problem start here that flat pistons  i need to know if i should use decompression 1mm plate with 2 original head gaskets which have 1.75mm from both sides ... at final its almost 4.5mm spacer between head and bottom of motor 

 

So there is also next option like 2.4 mm custom gasket from factory who made racing gaskets ... this gasket will be plated with metal from both sides and at finnal its 2.4mm spacer

Can someone tell me w/o compression counting? just +- 

 

Thx best regards Thomas from Slovakia with crazy trabi 

Have you seen these?

https://www.maxrpm.de/Compression-reduction-plate-with-integrated-cylinder-head-gasket-for-VW-Polo-86-86C-all-09-13L-engines-also-G40

 

G40 also had sodium filled exhaust valves.

Will need custom map for fuel and ignition.

Not seen a piggyback ECU, though Digifant can be reprogrammed or re-chipped. Sorry, no clue about that I'm a carbs guy.

 

How driveable do you need it off boost?

Sensible CR is 9.5:1. Hill-climbing or race try 8:1 (thicker spacer).

Too high, not enough fuel (11.5:1 AFR) , too advanced ignition and you'll get knock.

 

Cam choice will also affect dynamic compression ratio.

 

Eaton's a supercharger so the boost won't be as high as big turbo at high speeds due to greater friction/parasitic loss. 

 

Allow for good 3 to 5 bar fuel pump. Trabi gravity feed won't be enough pressure 😂

Superchargers don't use blowoff valve. G40 used a bypass valve that recirculated boosted air to the turbine scroll. It can be deleted.

 

Mini Cooper also uses a bypass valve with the Eaton. Uprated versions are available.

 

https://www.autos.com/aftermarket-parts/do-you-need-a-blow-off-valve-for-a-supercharger

Edited 12 December, 20223 yr by dvderlm

3F engine has bowl in piston for combustion, not flat.

 

Flat pistons are in early HH in Mk1 Polo, which has combustion chamber in head.

Haaa 😁 im so happy that this forum is not dead

also for lot of info 

 

-about blow off 

i know about bypass but with eaton i dont have to use it 🤔 and i think redundant air will be kicked out by blow off

 

-piggy back ecu mislead serial ecu

Which is connected to injectors and almost to everything and you can program it and map it with serial ecu

 

- so about decompresion plate

i want use it little bit at slalom/hillclimb

so +- which option i shoul use +- how thick plate i should use
2.4mm gasket with plate from both sides 

if its it not too much i can add one serial gasket which have 1.75 at final its 4.15mm

 

or 1mm steel plate + 1.75 gasket from one side and 1.75 gasket from other side

at final its almost 4.5mm but i think its too much for 0.8b pressure 

 

i know i know better will be to calculate it 
but im little bit lazy to calculate it and at least i dont know how to 😂

 

btw sorry for my poor english im from Slovakia

I've not got much to add, but I've always wanted to have a charged trabant (I'm not actually that fussed about g40's normally).

 

Don't worry about your English, it's perfect. I'll apologise for mine though, I'm from Lincolnshire.

Btw know here someone if at book about polo 80-86c from Haynes is full wire diagram and fuse diagram and ecu pins diagram?

thx

It has, but it's not great to work from.

8 minutes ago, Yeti said:

I've not got much to add, but I've always wanted to have a charged trabant (I'm not actually that fussed about g40's normally).

 

Don't worry about your English, it's perfect. I'll apologise for mine though, I'm from Lincolnshire.

if admin will be ok with upload of other car mark 

i can upload few photos 😁 

its still under construcion

Its on oz ultralaggera wheels , need to weld roll cage, and now im working on custom front axles.

front opel corsa callipers and brakes,opel corsa front coilovers, stabilization is deleted and upgradet with arms with unibal mounts 😁 and more and more

at final its will be maybe 600kg beast 😁

 

You might like to start a thread in this section of the forum https://www.clubpolo.co.uk/forum/65-non-polos/  where you can upload pictures of the "Trabby" I'm sure it will be of interest to quite a lot of members, but please keep any technical questions in the relevant section where this post is currently 

15 hours ago, Yeti said:

It has, but it's not great to work from.

i need some wire diagrams and cant find any diagrams at web,pdf or something 

i have some docs i can send over if you wish...message me with a email addy or whatsapp

4 hours ago, steveo3002 said:

i have some docs i can send over if you wish...message me with a email addy or whatsapp

Hi i sent you pm 

thx

calculating static compression

3F engine, bowl in piston

https://www.kmotorshop.com/en/article-detail/view/102195/piston-0299200-mahle-030107065p

says 75.01mm diameter piston(overbore for worn?). 

 

Combustion bowl is 57mm diameter and 13.2mm deep.

It has rounded corners and a central bulge of unspecified height.

Weird it added the image upside down and mirrored...?

 

Plus the valve pockets, so I'll guess at 65% of volume of a cylinder (or measure liquid which will fill the bowl).

33.7cm3 x 65/100 = 21.9cm3

 

And unitary cylinder is 75bore x 72stroke is 318cm3

Would be 318/21.9 = 14.7:1 CR with no gasket.

 

For 8:1 static CR you need a 318/8 = 39.75 cm3 combustion chamber, or an extra 17.85cm3. (39.75 - 21.9).

 

4.04 mm gasket spacer x 75mm diameter cylinder = 17.85cm3

 

Sounds big to me, but maxrpm sell one of 4mm.

 

The dynamic CR will be lower, and I'd need to find and look at Bell's book on turbo boost to find suggested adjustment for that.

 

Edited 16 December, 20223 yr by dvderlm

Need 3F or PY G40 stock cam valve timing, and conrod length but this looks useful for dynamic CR.

http://www.wallaceracing.com/dynamic-cr.php

 

 

 

https://www.gladen-motorsport.de/en/VW+G40+dbilas+camshaft+asymmetric+256-276-.htm

( a minor upgrade )

says

Camshaft asymmetric from dbilas 256/276°
VW 111 1.0 - 1.6 Liter 4 Cylinder - 2 Valve, cross flow cylinder head
dbilas item number: 23.141.011
Application: Street
Technical data:
- camschaft 256/276°
- valve lift 9,5/10,6
- valve lift at TDC 0,7/1,3
- Lobe Angel 112°
- Valve timing: : 16/60 - 70/26

 

So inlet closes 60 ATDC.

3F conrod 122mm

 

Wallace calculates for static CR 8:1, 12psi (just over 0.8bar) boost and 60° ABDC inlet closing for 3" (75mm) bore, 2.83" (72mm) stroke, 4.8inch (122mm) rod an effective, ideal CR of 12.06:1.

Should be fine with even small or moderate sized intercooler.

(assuming high octane fuel).

 

Static compression ratio of 8:1.
Effective stroke is 2.28 inches.
Your dynamic compression ratio is 6.64:1 .
Your dynamic cranking pressure is 127.83 PSI.
Your effective boost compression ratio, reflecting static c.r., cam timing, altitude, and boost of 12 PSI is 12.06 :1.
V/P (Volume to Pressure Index) is 25

 

 

Edited 16 December, 20223 yr by dvderlm

1 hour ago, dvderlm said:

Wallace calculates for static CR 8:1, 12psi (just over 0.8bar) boost and 60° ABDC inlet closing for 3" (75mm) bore, 2.83" (72mm) stroke, 4.8inch (122mm) rod an effective, ideal CR of 12.06:1.

Should be fine with even small or moderate sized intercooler.

(assuming high octane fuel).

 

Static compression ratio of 8:1.
Effective stroke is 2.28 inches.
Your dynamic compression ratio is 6.64:1 .
Your dynamic cranking pressure is 127.83 PSI.
Your effective boost compression ratio, reflecting static c.r., cam timing, altitude, and boost of 12 PSI is 12.06 :1.
V/P (Volume to Pressure Index) is 25

 

 

 

 

 

Damn  lot of info were added  here ... really thx for info 

I appreciate it!! 

 

Yep also i want to use IC and Oil cooler
We have 100 oct fuel at our country which i want to use 
You said few posts before that 4mm+ Spacer is too much 
So at final how thick decompreson spacer will be needed and usable with all those info,CR  😁

Camshaft i want use from 3f original 

ive non 3f boosted and they seem to cope , cant you swap blocks with another owner ?  they get high comp /more power and you get a lower comp motor

 

38 minutes ago, steveo3002 said:

ive non 3f boosted and they seem to cope , cant you swap blocks with another owner ?  they get high comp /more power and you get a lower comp motor

 

its not about block swap.. 3f its almost the same engine like g40 and g40 is supercharged 
Difff between those engines is just pistons(bigger holes because of compression) and sodic valves at head and g40 have flap with bypass to kompressor 

I need to solve just compression with decompression plate and order just right size/thick of gasket/plate 

or an abd is already low compression , if engines are easy to find its less hassle than a plate 

Spacer and gaskets of 4.15mm would be a cylinder of 18.33cm3 +21.9cm3 in the bowl gives 40.23cm3.

 

318/40.23 = 7.9: static CR

 

Plug that into Wallace calculator and you are at 12.5:1 effective boost CR. With high octane, big intercooler may be okay.

But two gaskets and a piece of metal is twice as likely for head gasket to fail between pistons, and the water jacket

will be working hard to take heat away,  exhaust valves will be hot and only have short contact at high revs so they may burn.

You can cool with more fuel or methanol/water injection but it is at the margin of to much, versus a 4valve direct injection Honda with good combustion chamber shape that can do 13:1 or higher effective boost CR.

 

Top of block and head would need refacing to be flat as possible, and not skimming too much otherwise CR rises.

 

Some Lotus Esprit turbo models had 7.5:1 static compression, but the HC ones were more desirable.

 

I've not even allowed for altitude, which you must have with hill-climb.

I live near enough sea-level.

 

Oh, yes, and a 4mm spacer surely means distance from top to bottom cambelt on the straight line (not round the water pump) is off by about a tooth I guess, so surely a vernier camshaft pulley is needed simply to compensate to get TDC aligned with valve events.

 

I suppose it stops being an interference engine.

You could fit bigger valves with little worry of them touching the piston.

Not sure on the hydraulic valve lift I guess about 11mm.

 

 

 

 

 

Edited 16 December, 20223 yr by dvderlm

thx for all info 
I will buy 2.4mm gasket which is plated with metal from both sides and one g40 1.7mm gasket 

Btw from which polo i can fit idk how to call it at Eng. - Control stick for change gears and also with rod which goes to gearbox?
Polo 6n? its same like 86c ? does not depend on the length of the rod to gear box/transmison just need to fit ending of rod to gearbox... 

 

Thx