Are 308 2V Blocks and 308 4V Blocks Interchangeable?

Hi Sam,
I am the guy rebuilding the motor for Bob, and I have compared the two block and they are near identical. All water and oil inlets match up with the head. So, there should be no problems using the 2v block. The only difference I have found is there are 3 ports in the top of the block for (oil temp unit or whatever else you may want to use them for) in the 2V block there are only 2. However, since only one is used this should not be an issue either. Thanks for your concern and the block arrived in wonderful condition.

Thanks


Wade
www.auto-corsa.com
www.308qvregister.com

 

I distinctly remember reading an article discussing this when the QV motors came out. While the bore spacing is the same, the oil and water holes don't match up. You can't put QV heads on a 2V block and vice versa.

 

I measured the distance of all oil and water inlets on both blocks and matched them to the heads. They DO match up.



Wade

 

and the layout of the studs in the block and corresponding bores in the heads is completely different.

Best Regards from Germany

Martin

 

from what i've heard they match up fine. it's the dia of the stud that is different between the two. not difficult to overcome, but an issue.

 

Thanks Sam, I know what you mean about shipping.

I have measured everything and have had the QV heads on the 2V block, EVERY THING lines up, no bolt diameter problem either

What I will do though when the block returns from the machine shop is make an acetate map of the block surface and match to the head just to be 100%

Also, I am sure Ferrari would not tell its customers they could not use 4V parts on a 2V car. No not Ferrari.

Wade

 

Wade,

Please keep us informed of the progress of the rebuild. It would definitely be useful information if, in fact, the blocks and heads are actually interchangeable.

Thanks,
Steve

 

Well just got word from the machine shop, and the block is a no go.

Seem all of the water inlets line up ,the oil injection ports line up, the bolt patterns line up and the corner anchors line up. The oil drain holes from the head to the block are off by a couple thousandth of an inch. The machine shope said it would work but you will always have a risk of leakage. So better to find an exact match.

Oh well back to searching for a QV Block


Wade

 

The intake ports are mismatched more than this. You could just be talking core shift.

I would break out the tig welder and die grinder.

Jay

 

Ha, the machine shope made some suggestions about doing just that, but nah!!




Wade

 

It would be interesting to hold up a QV head gasket to a 2V headgasket and see if the spacing for the holes on the headgaskets line up, are the same size, etc.

(If it was me and I already had the block I would have them machine in some O-ring lands that cover both holes if there's room. This is the low pressure side, right?)

 

The 4V head can be made to work on the 2V block. We are going to do that on Nick's next 3.5 liter build and on Mark Lewis 4 liter build.

The drain back holes can be elongated in the block with out welding. I would not try to elongate the holes in the head because there is a water passage between the drain back hole and the head bolt hole. Too much chance of breaking through the head.

You would use the 4V head gasket not the 2V. The 2V gasket would not provide enough overlap to seal the drain back hole in the 4V head as shown in second photo. The first photo shows a used Ferrari 2V gasket on a 4V head.
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So you have a spare 2V block now???