2v with 4v heads

[Yellow98Cobra]

I was talking to a guy at work and he said you can put 4 valve heads on a 2 valve. Is this true?

[slow86fiveoh]

Yes it is true, last year we used a built 2v shortblock that BES built in a 01 cobra with a procharger

[cstreu1026]

Generally speaking a 2v will have a larger dish in the pistons but the blocks are more or less the same

[JIMS SVT]

If you put 4v heads on a stock 2v shortblock you will end up with really low compression.

[Yellow98Cobra]

A guy at work said he was going to do it. I had never heard of anyone doing it. Figured it couldn't be that great of a mod or everyone with 2valves would be doing it.

[slow86fiveoh]

Considering n/a 4v has over 11:1 compression more of a dish in the piston wouldn't hurt much would it, most stock motors are around 9:1

[cstreu1026]

96-98 and 99/01 Cobras had compression ratios in the mid 9.0 range.

[slow86fiveoh]

My bad I'm thinking of my brothers car but it has mahle flat tops and the heads were re surfaced so he has a shade more than normal

[slow86fiveoh]

Ok after some research a 99 up shortblock with 99-01 4v heads would net u around 8.5:1 if the info was correct

[JIMS SVT]

96-98 and 99/01 Cobras had compression ratios in the mid 9.0 range.

9.85 is stock compression

[Night/MareCobra]

My dad wanted to do this to a 5.4 2v

[beercan5.0]

Pretty sure it will make the compression really low

[Night/MareCobra]

Good for boost though

[JIMS SVT]

Not with the stock rods pistons and crank.

[Night/MareCobra]

Wasnt even thinking about stock internals. Oops lol

[na svt]

Good for boost though

You don't want the CR that 2v pistons with 4v heads will provide, boost or not.

[2-8-1]

A guy at work said he was going to do it. I had never heard of anyone doing it. Figured it couldn't be that great of a mod or everyone with 2valves would be doing it.

It's almost always cheaper to buy a complete 4v than do that swap. Physically, yes they work just fine, it's basically the same engine, financially it's not usually advised.

[SVT Supra]

Yes it is true, last year we used a built 2v shortblock that BES built in a 01 cobra with a procharger

Was it a P1SC?