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Hi guy's, I built a nice 1600dp turbo engine for my bug and have now aquired a 1.9 DG engine which I fitted, I bought it from a guy that had it in his GHia, I need a bit more power but don't want to go full race as she's also a daily driver,

At the moment I have the following

Stock std internals
1 x 36 Dellorto blowthrough
Electronic ignition
I alternate between a T3/t4 and an IHI turbo from a FORD 2.5 Ranger ( which works well )
Charge cooled
C/ratio (a/p the seller) is now 7.3:1 (std is 8.6:1)
Boosting between .8 bar and 1.0 bar,
I have not dyno'ed but from the feel of it I'm sure this engine is capable of much more power, my 1600 a/cooled turbo pulled almost just as strong,

Is 7.3:1 compression ratio too low? I was thinking of opening up to see just how and why they dropped the cr so low,
I need the following advise please?
Will a set of 1.25:1 lifters work whilst keeping the hydro lifters?
I will balance all internals, is there a cam for hydros with the 1.25 ROCKERS?
What sort of power can I expect after doing all the above?

Find out how the compression was dropped too much deck height is not good. The compression can easily be 9 to 1 and still good for 10lbs of boost because it's watercooled and the piston design, but not with too much deck height (defeats purpose of piston/chamber design) .
1.25swill work with the stock cam and (some) type1 high rev outer springs, but coil bind and installed spring height needs to be checked.
A Single Dellorto carb is the hardest thing to tune when used with blow-through, they work much better as duals. A single SU draw through would be easier to tune or go to injection.
I tried a blow through single side draft and found it impossible to get mixture under control for mid range and top end due to my cam and turbo. Ran Ok naturally aspirated though.
Your power will depend on boost, timing, and mixture control along with an efficient combustion chamber. Compared to the 1600 the 1.9 should be enough to make you happy.
Do a search in this forum there are some dyno figures.

Thx for the info Joe, I was sure that the c/r deckheight is my problem here, I will open up the engine as soon as I find a decent gasket set and a workshop manual, I'm sure I'll have to replace pistons as I suspect that the builder may have shaved too much off the tops of the piston, would rather run it at normal C/r - 8.6:1 with less boost,

I will search for similar builds for some power output possibilities,

Thx's, again.

If you have the funds, invest in an engine management system. Carbs are not very reliable icw a turbo. Furthermore you will get much beter gasmilage, better throttle response and overall better torque and power. I used to have dual blowthrough dells, but they sucked bigtime compared to efi...
Just my two cents.....

Actually I prefer tinkering with carbs, FI too complicated for a garage build, was wondering if a 2.1 crank, sleeves, pistons and cylinder heads could be built over to my 1.9, I can get the parts as a friend of mine has decided to go oxyboxer on a 2.1.

Has anyone upgraded a 1.9 to 2.1 this way?

the 2.1 crank and liners go into the late 'B ' DG case o.k, a bit tighter in the early pre 'B ' cases, look carefully at the liners as they often have cracks that start at the bottom on the thrust side.

How do I determine if mine is a late "B" or a early pre "B" case?

Hi Guy's, back on the bench again, had troubles with the 1.9 Turbo water pushing out from the front radiator cap only under boost, after stripping I found a hairline crack between two valves running right up into the inlet and could in all propability cause the crack to open up under 1 bar boost and compress cooling system.

Now that Iv'e opened up I got a set of 2.1 AMC heads as well as pistons, liners and crank, this will make a 2.1 right?
Now Iv'e heard that the 2.5 had run with 98mm pistons and stroker crank,

Has anyone fiddled with 98mm pistons in a 2.1 sleeve wich is 94mm bored to 98.025mm to go 2293cc?
So if 98mm pistons will fit 1.9 conrods on a 2.1 crank in a 1.9 case basically
I like the idea of going to 2.1 Turbo but 2.3 sounds like a lot stronger, not sure about the pistons and liners as advised to me,

any thoughts?

My OKRASA 2.5 is 98 bore x 82 stroke pre B case, but it uses machine fit liners so the case is bored, very strong, you can't bore stock liners for 98mm pistons, the biggest piston in a bored stock liner is 96, even this is on the limit at the bottom liner skirt, someone on here did? do It, but it's gone very quiet as usual when things don't work, then you add a stroker crank for even more side thrust on the lower skirt at the now higher RPM required, and you can see the trouble brewing, the cracks always start at the bottom and travel upwards very quickly, either use a proper bore kit or Leave it at 2.1 and sleep nights, it's plenty big enough once the turbo gets boosting, the B cases have a three piece no1 main bearing and have the b part number suffix. The 1.9 rods are good on the 2.1 crank, even better with ARP bolts. Regards BBB.

buildabiggerboxer wrote:My OKRASA 2.5 is 98 bore x 82 stroke pre B case, but it uses machine fit liners so the case is bored, very strong, you can't bore stock liners for 98mm pistons, the biggest piston in a bored stock liner is 96, even this is on the limit at the bottom liner skirt, someone on here did? do It, but it's gone very quiet as usual when things don't work, then you add a stroker crank for even more side thrust on the lower skirt at the now higher RPM required, and you can see the trouble brewing, the cracks always start at the bottom and travel upwards very quickly, either use a proper bore kit or Leave it at 2.1 and sleep nights, it's plenty big enough once the turbo gets boosting, the B cases have a three piece no1 main bearing and have the b part number suffix. The 1.9 rods are good on the 2.1 crank, even better with ARP bolts. Regards BBB.

Thx's for the info, I think I'd rather "sleep" nights than " removing engine" nights, sound advice, thank you.