Sävar Turbo Site

Hi All.

I have been looking a bit around how to lower the compression ratio on the B234F to accept turbo.

Machining down the pistons 1,5mm in the bottom, and increasing the dish diameter to 81 mm will give me 23ml in the piston, 7mm squich band left and 4,5mm deep dish.
I wil retain a quite thick piston top, end at kompression ratio with the 16V head(45cc) at 8,5.

I would like to limit the squish a bit to not have too fast combustion.

Would it be better to widen the dish even more?

Picture of the engine bay currently:

Hi Henrik

With the looks of your setup it might be that you are at the borderline or past what the stock pistons can reliably endure...
Why not go for a proper setup in the first place ?

YS
Jens B

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Jens B
mrjaybeeze at hotmail com

you can have what compression you want, as long you have full control over your ignition timing

Hi Mrjaybreeze

There is a big difference between going for a fully strong enough setup in the first place, to this setup now.

Currently im sourcing a junkyard B234F complete engine as low as 2000dkr, adding a set of china conrods and modifying the rest. Should such an engine blow up somewhere in the learning curve, im not too sad.
A friend of mine ruined a set of wiseco pistions last year simply because a wiseco wrist pin was a lot less stiff than the stock volvo one. It simply bended over time. The devil is in the details.

So what im doing now, is to trim the stock half-wornout parts and over time gaining enough knowledge to eventually build a stonger engine with a longer lifetime.

Also, most importantly, i see a lot of the pleasure in building as many things as can possibly be done myself, buying as few parts as possible, which is the main driver for the setup as it is now, and, yes, why not go for a stronger setup.
I understand why you ask, but then i only get the pleasure of the assembly process, and someone else did the design and thoughts behind it.

what engine management system do you use?

In the DIY spirit, i have built quite a few MS1 based ECUs(Not based on US design, but my own), and if i run out of time, it will be started with one of these. If i get the time i was tempted to design a new ECU around the MS3 CPU.

Buying a MS3 wont be an option, as there are then many other options equally expencive.

So i dont know, how its going to end exactly, but do have som ideas.

What fuel is planned?

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///AMG
Älskar att få kärleksbrev, tyvärr är jag upptagen så ni får vänta.....

Sorry, very relevant, forgot to mention that.

The idea now is to run it on 98 shell vpower. I would like to end with a happy engine that doesent need tons of boost to wake up, but on the other hand dont burn so fast that it gets picky and nervous from a knock perspective.

I currently have a plan giving 7mm squish edge around the piston with 3,6mm deep dish. This yields 9:1 in compression ratio.
i aim for 0,9mm squish height.
Obviously the 16 head doesent have squish all the way around.

Let me know how bad im off with this idea.

I dont have a power target, i will end with increasing the power little by little while i learn to drive the car, and see where it brings me.

sounds good.
v-power at your place.. is it still 'v-power' or the junk as in sweden?

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///AMG
Älskar att få kärleksbrev, tyvärr är jag upptagen så ni får vänta.....

So far Vpower in DK, is significantly better than normal 95octane.
I believe its the best we have, rated 98octane.

No official source to obtain ethanol enriched, or similar fancy fuels

Hej ska du plocka seriös effekt med vanlig bensin så sänk förbrännings hastigheten med större klämspalt ca 3mm sen satsa på lite vassare kamaxlar och mer rpm och plocka effekten med sugmotoreffekt. obs viktigt då med lågt avgastryck och fint grenrör och insug som gärna är ganska kort och sen en effektiv laddtrycks styrning och gärna knack sensor som är aktiv som på vems.

mvh jens

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Jensas Speedshop
Den senapsgula 142an med B20 10.61sek/402m
B20 Vegan 5.92/185 9.50/225

Samarbetar med: KL Racing | Lube Tools | | AGAP | VEMS

seriös effekt.. menar du då 1500 eller mer ändå?
~1100hk går att plocka på E85 med hög komp(över 10-1) och squish liknande Henrik skrivit.
Men givetvis inte med std kolvar.

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///AMG
Älskar att få kärleksbrev, tyvärr är jag upptagen så ni får vänta.....

Knappast relevant info att snacka etanol-effekt när han utryckligen säger att han inte kan få tag i det på hemmaplan.

Kör på Jens recept Henrik! Det låter vettigt och liknar det du redan påbörjat.

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//Pacman

Thanks for the good feedback.

We all need to start somewhere, so now i went rather big for all engine exteriors, and yes, the stock pistons may not hold up, but its a starting point.

Im a bit reluctant to just go large on the squich height due to previous experience that another engine got really sluggish this way(dual head gasket with spacer in between), but it was different in many ways, so i am not in a position to really argue against the 3mm squish height.

It will be alot easier to get methanol than to get E85 or similar in smaller quantities, but i need to be able to fuel it on a normal gas station.
Sheel Vpower is what im building for now.

I do not have have the exterior exactly like Jens describes the intake. I have nearly 250mm intake runners that are 55mm at the bellmouth coning down to ø44 equivalent at the head transition. Idea was to get the longest runner possible to gain bottom, and im not so sure after thinking twice that it was worth the effort. Most likely there will be tons of torque before the runner lenght becomes a true adder. Its there now, and im not too fond of it, so its one of the things that is not ticked off as completed. For now, it will have to do.

Exhaust should be fine i hope.







I still have a few options to pick from squish area wise:

Current setup: Tight squish, 7mm band, compression ratio 9:1
Alternative1: Go for tight squich, 4mm band, compression ratio 8,5:1
Alternative2: Use FT pistons instead, and mill away the entire squish band. Guesstimate the comp ratio will drop to 8:1 or so.

Alternative1 is actually nearly no squish at all on the 16V head allready. The head doesent have nearly as much squich as 8V, and when opening the dish in the piston the squish area drops significantly.

@Jens; What does the term "serious effect on normal bensin" mean in this forum in terms of actual HP levels?

Im going to start the car on stock cams for ease of startup, but given the crowd has seen the engine setup, what cam setup is recommended as next step, (keeping the hydraulic lifters for now)?

And who can supply such cams?