2.2 Heads on a 2.0 engine

I have a set of good 2.2 heads and a stock 2.0 911T engine. Can the 2.2 heads be bolted on as a straight substitution for the 2.0 heads or will I encounter some problems?

That depends upon whether there are carb/fuel injection incompatibilities with regards to threaded ports for injectors ... if donor engine was F.I. and 2.0 had carbs, you will need to plug the injector holes, but vice versa presents a problem!

There may be port size differences to address, as the 2.2 -2.7 heads had bigger valves and several port size variations!

------------------
Warren Hall
1973 911S Targa

[This message has been edited by Early_S_Man (edited 12-06-2000).]

The heads do not have threaded ports for injectors and the valves are 42mm intake and 38mm exhaust.

OK, for the 2.0 ... and the 2.2 heads???

Port sizes, intake and exhaust?

------------------
Warren Hall
1973 911S Targa

Your 2.0 cylinders maybe steped and the 2.2 heads will not be steped, where the cylinders meets the heads matting surface.
What is the year stamp on the heads that came off the 2.0? and what is the year stamp on the 2.2?

Roy at http://www.motormeister.com

I do not have the information from my 2.0 heads although the engine is the original engine from a 1970 914-6(still in the car). The part number on the 2.2 heads is 901.104.306.2R - 70.

Look on the heads there will be a circle with a raised numbers in the center of the circle with the month and year> 6-69 = June of 1969, what is odd we have seen the 1969 heads comming with both the step and non step
take a peak, or just compare the heads and see if one is steped and the other is not or they are both the same (non-steped).

Roy at http://www.motormeister.com

The month and year stamped on the heads are: 5-70. I measures the valves and they definitely are 42mm intake and 38mm exhaust. I measured the ports and they are 32mm. Evidence points to these heads actually being 2.0 heads, not 2.2 heads. Any further ideas?

PHOTO OF THE HEADS: http://www.rgrautoparts.com/porscheheads.html

That part number (and the valve sizes) corresponds to the casting number in Bruce Anderson's Porsche 911 Performance Handbook, 2nd ed. p. 69, for '69 911T heads ... which would also be the same as '70-'71 914/6 engines! So, I guess you have your answer.

------------------
Warren Hall
1973 911S Targa

I appreciate all of the help, guys. I am delighted with the result.

Gord

The 2.0L heads used a paper-type gasket; the 2.2L used a CE ring gasket. Also, the diameter of the 2.0L combustion chamber is 80mm; the 2.2L is 84mm.

[stownsen914]

Originally Posted by RSR935

The 2.0L heads used a paper-type gasket; the 2.2L used a CE ring gasket. Also, the diameter of the 2.0L combustion chamber is 80mm; the 2.2L is 84mm.

I'm reviving an ancient thread to hopefully confirm the statement above. I had an idea to put 2.2 heads on a 2.0 motor to take advantage of the larger valves and more open combustion chamber, but it would not make sense if the combustion chamber of a 2.2 head is larger in diameter than the 2.0 cylinder! Is this the case?

I'm thinking that the different gasket types with 2.2 and 2.0 could be handled with machining, but the diameter difference mentioned above would be a non-starter for this plan ...

Thanks.

[Flat6pac]

The 2.0 cylinder is taller but the 2.2 cylinders will fit in the 2.0 case so change everything.
Bruce

[pors1968]

You can use 69 2L head the valve are bigger than standard 2L.

[larrym]

the differences in that quote from RSR935 are correct

80mm vs 84mm is the key factor

- you are going to spend a lot of money on machine work to accomplish what can now be done instead with relatively cheap used parts - cheap core motors with all the parts you need are easily found

CE ring cyls have a groove in them for the ring & machining it away will change a whole lot of critical dimensions -

enlarging the head chamber will change CR

a slippery slope awaits

long long time ago i had a set of 2.4 heads machined to fit larger dia 2.8 - lots of money spent & lots of subsequent fit issues & unfortunate CR effects - would never do it again (i was a 1st time novice on 911 motors back then & got lots of advice from folks who had not actually done it)

so - repost your question to include "please reply if you have actually done this"

Originally Posted by stownsen914

I'm reviving an ancient thread to hopefully confirm the statement above.

I'm thinking that the different gasket types with 2.2 and 2.0 could be handled with machining, but the diameter difference mentioned above would be a non-starter for this plan ...

Thanks.

[stownsen914]

I should have made it more clear what I am trying to do. I would prefer to keep the 2L displacement as this will be in a vintage race car, and 2L is a common displacement limit. I thought of the 2.2 heads to take advantage of the larger valve sizes. If those heads could be made to work, I would use custom pistons to ensure enough compresion.

I wonder if the head to cylinder mating surface could be cut down to reduce the diameter of the combustion chamber to 80 mm (I should be able to go as far as 81mm).

Thoughts?

[BURN-BROS]

There are quite a few obstacles that create a real challenge keeping 80mm cylinders on a 2.2 head.

You would need to notch the cylinders in order for the valves to clear

You would need a 80mm cylinder that sealed like a 2.2

Top ring land location would have to be much lower on the piston for the different valve pocket location.

In the end, there are too many compromises for the benefit of the larger valves.


An alternative would be to destroke a 2.2

84 x 60 = 1.99 liters

There are issues going this route as well

Longer rod along with a pretty heavy piston.


Most guys just pony up and put larger valves in the 2.0 liter head.

[Flieger]

Originally Posted by BURN-BROS

There are quite a few obstacles that create a real challenge keeping 80mm cylinders on a 2.2 head.

You would need to notch the cylinders in order for the valves to clear

You would need a 80mm cylinder that sealed like a 2.2

Top ring land location would have to be much lower on the piston for the different valve pocket location.

In the end, there are too many compromises for the benefit of the larger valves.


An alternative would be to destroke a 2.2

84 x 60 = 1.99 liters

There are issues going this route as well

Longer rod along with a pretty heavy piston.


Most guys just pony up and put larger valves in the 2.0 liter head.

Is there someone making 60mm stroke cranks or would that be just as custom as the rods?

[BURN-BROS]

Originally Posted by Flieger

Is there someone making 60mm stroke cranks or would that be just as custom as the rods?

No off the shelf cranks that I am aware of. It's not a common route to go.

It would be a offset grind to the stock crank and custom rods to use 2" clevite bearings.

Rod would need to be 3mm longer to keep the compression distance stock.