Help with a Nova Rossi 35 plus

[FloridaScaleBoater]

Ok folks, as mentioned.
Nova Rossi 35 plus
I have no history on this engine.
New piston sleeve, rod, head and button. New bearings.
I cannot get the water cooling head to seal on the top of the head button?
Have lapped the bottom of the cooling jacket.
Seems to leak worse in the center around the glow plug?
I fill the water line W/ alcohol, plug the outlet, blow threw in and fills the center recess with alcohol.
Put my hand over the center and can see some alcohol coming out around the perimeter of the cooling jacket.
Could the screws maybe be too long and bottoming out before it actually clamps the cooling jacket down?

 

[shoboat]

Rick,
How long are your cooling jacket bolts?

Thanks,

Mark Sholund

 

[FloridaScaleBoater]

Rick,
How long are your cooling jacket bolts?

Thanks,

Mark Sholund

Will have to measure, Tomorrow.
Too Frustrated & late to be in the shop

 

[longballlumber]

Based on the exploded view on the site:

NV01001 M3.5X18 Head Screw​

 

[FloridaScaleBoater]

Thanks, will have a look the evening.

 

[dave roach]

You mite look at the threads in the block and run a tap in them.Mite not be taped to the bottom of the hole.

 

[FloridaScaleBoater]

You mite look at the threads in the block and run a tap in them.Mite not be taped to the bottom of the hole.

Thanks for the suggestion,
Tried shorter screws last night. No change.

 

[Brian Sorgente]

Couple suggestions.

When you tighten the head down, can you see a space between the top of the engine case and the bottom of the head button? Depending on the parts you're using, sometimes the top of the 35+ cases needed to be machined down so the outside of the button wouldn't sit on the case. It should only be sitting on the liner, leaving a space between the two. I had to do this with my 35+ engines.

I know you said you lapped the jacket onto the button, but maybe the fit is still off? I'd check to see if the ID of the jacket might be sitting on the radius of raised section of the button where the glow plug gets screwed in. If it's sitting on the corner, try countersinking the bottom of the jacket hole a little to give it some space.

Brian

 

[SayMikey]

Pictures tell 1000 words

 

[FloridaScaleBoater]

Wasn't able to check with straight edge... had to play plumber this evening.
But some pics for you Mike.

 

[steve wood]

my 2 cents. my experiance with many,many novas, if it has the oring,throw it away.oring is supposed to reduce vibrations,has nothing to do with sealing. more than likely the head button is sitting on top of the rough casting outside of the machined surface surrounding the liner. when i was doing lots of novas,the first thing i did was throw the case in the mill and face off this area.if the engine had enough head shims under the button it would clear this area,but if you cut the head clearance to our normal .007 it never would. in a pinch you can use a belt sander to do this, you can use any method as long as you keep the shavings out of the bearings. pull the crank and stuff paper towels in the holes and cut away. had one engine someone else worked on was so bad the liner was not even down tite. piston was hitting head button, liner was going up and down with the piston,engine was destroyed,nocked out piston,rod bushings,crank pin,bearing bores, the big bearing would fall out of the case when tipped up.no doubt in my mind this is the problem

 

[SayMikey]

The Nova Master has spoken. Good to see you hear Steve

 

[FloridaScaleBoater]

Well, looks like Steve is the winner, winner, chicken dinner.
I don't have a mill to do this Job "correctly" but my belt sander and piece of glass with 600grt paper for lapping seems to have done the trick.
Thank you for the advise Steve.