I am looking to purchase a long block and add on all my accessories to it. My question is will the cam installed cause water reversion without going full dry? The long block is a gen v hp500 full roller and internaly balanced, eagle crank and je pistons, H beam rods.

Here are the cam specs I was given:
Hyd roller
240 int
248 exh
Duration @.050"
Lobe sep 114
Gross lift 620 int 629 exh

The cam specs are very close to the crane 168771.

My plan was to have my emi risers extended and have the pipe dry to the transom then introduce the water before it exits the hull.
Will this work for me or is a full dry tail a must with this cam?
Thanks
Derek.

It should be ok, but there are no guarantees. The cam is just a little bigger than a 525EFI cam.

I agree with Griff. Although making extending the tails would help.

Griff and Mild,
Thanks for the reply's.
It looks like its gonna be a go with this long block so I will be sending my risers out to Eddie marine for extension on Monday or Tuesday. The riser will measure 21.5" from the center of the exhaust hole on the manifold to the end of the riser. That will put the end of my riser about 3/4 to 1" from the inner most part of my exhaust tip, then I will use my existing rubber coupling to connect the riser to the exhaust tip.
Does anyone see a problem with my installation plan?
Also would a water relief valve installed before the water enters the motor help to prevent reversion?
Thanks again
Derek.

Your set-up should be fine. With an LSA of 114 there shouldn't be issues.

I had a similar setup on a 468 with 112 LSA and that had issues!

The Crane 731 runs 114 as well without drama.

The Crane 731 has a 112 lobe sep. I ran one in my 525SC and didn't have any issues, but the 731 has quite a bit less duration than the cam posted.
http://www.summitracing.com/parts/crn-168731