3.2 cylinder heads on 3.0 SC std cylinders/pistons

[911-lightning]

Is there any issues with fitting 3.2 cylinder heads to stock 3.0 cylinders with stock pistons? My plan was to fit 3.2 cylinder heads and 3.2 intake to my 3.0 SC engine with stock cylinders and pistons together with a planned turbo build.

As far as I can see the heads look almost identical except from the intake and the outlet port. But I guess this is not the first time you guys have seen this question

[Jonny042]

No issue as far as I know. There are sealing rings between cylinder and head on the 3.0 that are absent on the 3.2, but the difference is on the cylinder side.

[911-lightning]

Originally Posted by Jonny042

No issue as far as I know. There are sealing rings between cylinder and head on the 3.0 that are absent on the 3.2, but the difference is on the cylinder side.

Thanks! I know about the seal on the cylinder but it looks like the surface of the 3.2 and the 3.0 cylinder head is the same. So I do not think this should be an issue. What I was more afraid of is any differences in travel length of the intake/exhaust valve that would result in it hitting the piston or anything catastrophic like that.

[pkabush]

What Jonny said. I have two 3.3 turbos. One with 3.0 heads and the other with 3.2 heads

[Flat6pac]

Don’t forget your spacers to get the proper head height.
Bruce

[john walker's workshop]

And intake port matching.

[pkabush]

Those are good points. I ported both my manifolds to match.

[fred cook]

When I built a 3.3SS engine for my SC, I used a set of Carrera heads with a set of LN Engineering cylinders without any issues. The Mahle pistons were supposed to be 10.8:1 but tested to be 11:1. Probably due to some minor machine work on the heads at some time in their lifespan. I did use a large port (early) CIS airbox and matched the ports to the intake runners. Also did some work to match the pipes on SSI exhausts. Of course, the idea is to prevent introducing turbulence at the junctures.

[Nditiz1]

Not to steal this thread, but along the same lines. Is the same true for using 3.2 C&P with 3.0 heads?
I read you don't need to use the copper gasket and offset the wrist pin bushing .030"
Is that modification to the 3.0 rods just simply moving the bushing at the end of the rod towards the flywheel by .030"?

[911-lightning]

Originally Posted by Flat6pac

Don’t forget your spacers to get the proper head height.
Bruce

Thank you for the info, is this the spacer that you normal use with the 3.0 cylinder (the groove in the cylinder)? Or is this the spacers between the case and the cylinder? Is it possible to order in different sizes or do I just stack them to get to the right clearance?

Thanks

[911-lightning]

Originally Posted by john walker's workshop

And intake port matching.

I plan to use the 3.2 intake that I have so then I guess this should be ok? I dont think I need the normal "blocks" between the cylinder head and the intake then since both are 3.2.

Thank you.

[911-lightning]

Originally Posted by fred cook

When I built a 3.3SS engine for my SC, I used a set of Carrera heads with a set of LN Engineering cylinders without any issues. The Mahle pistons were supposed to be 10.8:1 but tested to be 11:1. Probably due to some minor machine work on the heads at some time in their lifespan. I did use a large port (early) CIS airbox and matched the ports to the intake runners. Also did some work to match the pipes on SSI exhausts. Of course, the idea is to prevent introducing turbulence at the junctures.

One of my fears is that the dome-shaped pistons on the 3.0 is not compatible with the 3.2 heads. So that this could result in the valves hitting the high dome. I see that most "aftermarket" pistons have more a flat top with pockets. Just wounder if i need to switch to thees types of pistons. But I dont want to since they cost a pretty penny

I am planning to run a 930 stock exhaust on the 3.2 heads, not sure if the port size is the same here so maybe I need to get some modifications done here.

[pkabush]

930 exhaust ports are smaller than 3.2 ports

[911-lightning]

Originally Posted by pkabush

930 exhaust ports are smaller than 3.2 ports

Thank you for the info, do you know the difference? Might need to go a different rout with the exhaust then.

[targa72e]

3.0 and 3.2 heads are interchangeable both directions, IE 3.0 heads on 3.2 or 3.2 on a 3.0. They have the same volume, valve size and valve angle and use the same camshaft profile The 3.2 heads have a shorter mounting height to the intake boss. There is a spacer that goes between the intake manifold and head. The studs on the 3.2 are longer to work with this spacer. The 3.2 heads have larger ports. 3.0 heads come in two different port sizes large (early and Euro) and small (later US).

3.2 Cylinder are dimensionally the same as 3.0. 3.0 cylinder use a CE head gasket and 3.2 cylinders use no head gasket.

The pistons and rods are not interchangeable. The piston pin is 22mm on 3.0 and 23mm on a 3.2. The piston pin height is also different, The pin height is higher in a 3.2 do to the 3.2 longer stroke (74.4 for 3.2 and 70.4 for 3.0). To accommodate the extra stroke on the 3.2 the pin height was pushed higher and the connecting rod is shorter by .7mm.

john

[pkabush]

Originally Posted by 911-lightning

Thank you for the info, do you know the difference? Might need to go a different rout with the exhaust then.

I don’t recall of the top of my head. Google will probably revile the answer.
Or, someone with a better memory than me will provide it. I have thick flanged B&B headers that I ported to match. This could also be done with 3.2 headers.
I think they have thick flanges.

[911-lightning]

Originally Posted by targa72e

3.0 and 3.2 heads are interchangeable both directions, IE 3.0 heads on 3.2 or 3.2 on a 3.0. They have the same volume, valve size and valve angle and use the same camshaft profile The 3.2 heads have a shorter mounting height to the intake boss. There is a spacer that goes between the intake manifold and head. The studs on the 3.2 are longer to work with this spacer. The 3.2 heads have larger ports. 3.0 heads come in two different port sizes large (early and Euro) and small (later US).

3.2 Cylinder are dimensionally the same as 3.0. 3.0 cylinder use a CE head gasket and 3.2 cylinders use no head gasket.

The pistons and rods are not interchangeable. The piston pin is 22mm on 3.0 and 23mm on a 3.2. The piston pin height is also different, The pin height is higher in a 3.2 do to the 3.2 longer stroke (74.4 for 3.2 and 70.4 for 3.0). To accommodate the extra stroke on the 3.2 the pin height was pushed higher and the connecting rod is shorter by .7mm.

john

Thanks a lot John!

I will be using the 3.2 intake manifold so I guess there is a gasket between the head and the intake but just for sealing purposes?

The gasket on the 3.0 cylinder, will this be a problem with the 3.2 heads or will it seal like it does with the 3.0 heads? As far as I remember the sealing surface on the 3.2 and the 3.0 head i both "flush".

[targa72e]

There is a spacer (about a 1/4" thick that goes between the head and intake on the 3.2. Each side of spacer has a gasket.



Sealing surface for 3.0 or 3.2 head is the same.

john