2.2T rebuild - light hp/torque little improvement

[1974phil]

Hi Everyone,

Assessing the parts while tearing down my 2.2t Engine, I had to conclude that my original "O" pistons are out of tolerance 83.90mm-83.92mm vs 83.97mm

The original non counterweighted crank is within specs 56.975-56.98mm on the main journals and rod journal are all at min. 56.98mm, crankshaft to flywheel bearing is at 64.99mm.

Now, as I have to change the pistons and cylinders, I am considering to use AA pistons 84mm set. I have used AA pistons for my hi-po VW typ 1 engines with no issue (200hp), albeit forged ones, and I am not sure that the price difference for a basic Mahle set is worth the money.

I know that hypereutectic pistons are better than forged pistons for pure street driving in terms of longevity for low power engines.

With the "basic" low comp hypereutectic kit from AA with 84mm pistons and 66 mm Crank you match the original CR of 8:5 - 8.6 :1.

There is also a hi comp hypereutectic kit for 84mm pistons and with the 66mm you reach 9.1:1 CR.

I was wondering if anyone has used this last kit, with the 2.2 T cams/heads and what would be the outcome in HP and torque values.

Perhaps, switching to "E" cams could be worth it. Although my T cams look fine (haven't measured the runout yet).

I will keep my Zenith 40 TIN carbs and really I am by far not looking for "s" specs.


What is your view about these little changes vs. original specs (mostly meaning the High po pistons/cylinder set). Would I reach ca. 140hp from the 2.4T ?

Before considering the AA set, if anyone has used them lately I would be most interested in a feedback in terms of out of the box measurements.

Thanks for you help !

Phil

[Noah]

I had a similar situation on my 2.2T, p/c's were bad but the rest was good. I did all the case upgrades and used Mahle S p/c's (stock displacement) and 104/102 cams, which I understand to be basically Solex grind. It drives nicely, but definitely runs out of breath above 5500 RPM's. I should have ported the heads. Overall it's a nice upgrade from stock, but nothing earth-shattering.

[30westrob]

I think 9.1 CR with E cams would be a good combo, without break the bank upgrades. General rule compression and camshafts go together.
I have no experience with AA pistons. Rob

[Richy]

T and E cylinder heads have the same port sizes , so E cams are an easy upgrade , and use E pistons and cylinders . This will be a very noticeable improvement . Maybe you can find some good used E P's and C's ,
people want to "upgrade" their E to an S .

[dho]

Phil, I don’t have any info on the AA set, but, for your reference, this is what I did on my 2.2T: bored the cylinders 1mm to 85; used JE pistons that gave a measured 9.4:1 cr; had the cams reground by Webcam to the Solex grind; and put 32 mm venturies and larger jets in the Zeniths. The result was a noticeable increase in torque and horsepower, but still very drivable. I posted the dyno sheet last year. The torque curve is flat, with a peak of 155 at 5300 rpm; hp peaked at 173 at 6300 rpm. I am pleased with the outcome.

dho

[1974phil]

Hi,

Thanks for your input.

Richy, I have read that E heads have 32mm ports and T heads are 30mm but have not measured them yet. Valve size is the same though. I’ll check this.

DHO, are you using the stock 2.2T crank with this type of hp range?

I am targeting around 150hp max. Don’t want to put too much stress on the crank and here you are not allowed to increase power by more than 20% of the original power output as there could be insurance issues.


I suppose that using the AA hi comp kit with 84mm pistons should bring me up to 140hp with the T camshaft.

[geneulm]

You won't have trouble with the crank. Racers have used non counter weighted cranks for much higher HP applications.

The issue will likely be with the cylinder cooling on higher horsepower applications (Porsche used biral on E and S?) There has been a lot that has been written about successfully using these AA combos by engine builders over on pelican; including the use of piston squirters etc.

[1974phil]

HI geneulm,

Thanks, then I'll go with the Biral AA P&C kit and probably the high comp.

[dho]

Yes, I used the stock crank.

dho

[lkadams]

Phil,

You'll find lots of opinions and the engine rebuilding forum over on the bird is a good way to dig. There's a lot of expertise out there - but a lot of it is based in SoCal at sea level. I'm at higher elevations, so took a few gambles with my engine (my car is a 69 912 converted to 911 power, so I have absolutely zero invested in originality). I had a 2.0E motor that kersploded on a 2500 km drive to Luftgekhult in 2017. So I rebuilt with the 86mm AA high compression pistons (I wouldn't necessarily recommend that to you - there's a big risk running high compression single plug - but I calculate I lose about 0.6 CR due to elevation) which I run with a Dougherty Racing mod-Solex grind cam off the E cores (decent amount of overlap on that cam which lowers the dynamic compression, but adds a bunch of usable torque), using 2.2 T heads un-ported (in theory the smaller ports give higher velocities at lower airflows for better down-low torque), Weber 40 IDAs and a 123Ignition bluetooth distributor. I had the case worked over by Neil Harvey at Performance Developments - oil bypass mod (requires a later oil pump), piston squirters, line bored. Dealing with a magnesium case is the biggest cost and pain of the rebuild.

I wasn't looking for a 7200 rpm screamer, just something punchy that made 3000-6000 rpm fun and sure got it. However I can likely never drive down to sea level unless I run AvGas (ha!). So in your case, I'd be OK with the AA piston set - you can get some free displacement by going to 86 mm, aim for compression ratio around 9.5:1, swap out your cams for E grind or mod-Solex type (WebCam offers their own version of the mod-Solex), T or E heads are fine (as long as they aren't 2.0 heads), do the work to the case and put in piston squirters for sure, ensure your distributor is still within spec for advance (or modernize it) and have fun.