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getrdunn 10-26-2016 07:16 PM

That's some great power coming from edelbrock oval port heads. Somebody evidently worked some magic with them to get those kind of numbers. Although headers and water pump only..

mike tkach 10-26-2016 07:18 PM


Originally Posted by NDH2O (Post 4494625)
The center of the piston is .005 above the deck but with piston rock it could be as much as .018 above the deck.

i would use a head gasket at least .060 thick.

Boatally Insane 10-26-2016 08:28 PM


Originally Posted by NDH2O (Post 4494524)
Thanks for the comments, keep them coming.


I did a similar build..

Ran 82 mph in my 26 Corsa naturally aspirated...

Haven't run it in a boat with the blower yet, I bought a different boat and haven't had a chance to install this engine..

N/A dyno...
https://drive.google.com/file/d/0B8O...ew?usp=sharing

https://drive.google.com/file/d/0B8O...ew?usp=sharing




Link to my build...

http://www.offshoreonly.com/forums/g...o-results.html

getrdunn 10-26-2016 08:37 PM

Nice work. Cam specs look familiar for some reason. Btw any flaws with injectors etc or has it been pretty stable.

NDH2O 10-26-2016 08:53 PM


Originally Posted by getrdunn (Post 4494737)
I read the link from your above post and did I read correctly that the OP ended up with the edelbrock e street oval port heads. 290cc. Maybe 300-305 after port work. Would like to have seen what those heads flowed after port work and assuming lager valves. I thought I read at one point he made 694 hp at 5350???? Yet dyno sheet showed 682 at 6,000 however claimed to make over 700. Unless there was another posted dyno sheet I didn't see. I will go back and read from the start 1-4. Regardless good results. Your 315's will offset the CR hp loss I would think easily.

That forum post was a little hard to follow but either way it made decent power.


Originally Posted by Boatally Insane (Post 4494781)
I did a similar build..

Ran 82 mph in my 26 Corsa naturally aspirated...

Haven't run it in a boat with the blower yet, I bought a different boat and haven't had a chance to install this engine..

N/A dyno...
https://drive.google.com/file/d/0B8O...ew?usp=sharing

https://drive.google.com/file/d/0B8O...ew?usp=sharing




Link to my build...

http://www.offshoreonly.com/forums/g...o-results.html

Awesome, exactly what I have been looking for.Thank you! I bet those injectors were about tapped out.:D

Boatally Insane 10-26-2016 08:59 PM


Originally Posted by getrdunn (Post 4494785)
Btw any flaws with injectors etc or has it been pretty stable.

Don't know yet.. I've only put about 10 hours on it in the Corsa without the blower and decided not to continue with that hull....

Bought a Velocity 290sc, Hopefully be installing the 555 before next summer...

MILD THUNDER 10-26-2016 10:31 PM

1 Attachment(s)

Originally Posted by Boatally Insane (Post 4494781)
I did a similar build..

Ran 82 mph in my 26 Corsa naturally aspirated...

Haven't run it in a boat with the blower yet, I bought a different boat and haven't had a chance to install this engine..

N/A dyno...
https://drive.google.com/file/d/0B8O...ew?usp=sharing

https://drive.google.com/file/d/0B8O...ew?usp=sharing




Link to my build...

http://www.offshoreonly.com/forums/g...o-results.html

I noticed those IAT temperatures on your dyno sheet. Pretty cool info. I always thought the prochargers were soooooo much cooler running , and how you could run way more boost than a roots. Those IAT readings, are basically the same , if not a little hotter, than my 420 Mega Blower making 8lbs boost with a superchiller on the dyno. I love actual data, rather than "heresay" or someones "opinion'' based on sales and marketing claims.

You made that power with a 239/246 cam in full marine dress with EMI manifolds with an M4 and only 9 lbs boost, thats pretty good.. Maybe the 244/256 crane 651 would have been better. I don't know. You also dyno'ed that engine without the procharger as well didn't you?

MILD THUNDER 10-26-2016 10:55 PM


Originally Posted by NDH2O (Post 4494625)
The center of the piston is .005 above the deck but with piston rock it could be as much as .018 above the deck.

You won't get .018 above the deck under operating conditions. The piston grows when its hot.

With a .051 gasket, and even with the piston rock at max, you'd still have .033 of clearance. Once the piston grows, the rock will be less. If you were to average the measurement, say .018 above deck when rocked cold, and say, .012 below deck when rocked the other way, you can say, the piston is .004 above the deck, and use that for your measurment. Thats how I was taught to do it, using a deck bridge and a dial indicator. So far it seems to work.

Full Force 10-27-2016 05:41 AM

I guess my point was why buy the heads assembled and spend more making them right, that's why I said bare, the rockers I listed are not shaft mount, still a stud mount just steel over aluminum..


Originally Posted by NDH2O (Post 4494720)
Definitely, the best cylinder head guy in the state is a good friend of mine so I have no doubt that they will be right when I bolt them on. The whole idea of stud mounted rockers is a step back in time for me but at hydraulic roller pressures I don't think shaft mounted rockers are necessary. I could only find one dyno sheet with the Howards cam I'm looking at and it made right at 700hp @ 5950 rpm (more compression and smaller heads though)

http://www.chevelles.com/forums/89-e...install-2.html


Black Baja 10-27-2016 05:49 AM

Scorpion stud mount .612" @ valve 700+hrs and still going. Very surprised the roller tips aren't getting flattened out because of the hydraulic rollers. But they still look new...


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