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Now I'm more confused with the cooler vs hotter coolant temps lol.

This is on a street turbo build. I have warmer block temps but also a lot hotter exhaust valve when in boost.

Quote:

Originally Posted by underpsi68 (Post 4682019)

Thanks for the input everyone.

It seems like there is a little discrepancy on the intake but. .002ish on the exhaust. I think the exhaust was tight on mine and caused a few valves to stick. Would definitely explain a few wacky things that were going on with the engine.

Other thing to note is I run a 195 thermostat to make the e85 ignite better with cold air temps. I can change to a 180 stat but in the warmer months the engine runs on the warm side and I wont be able to keep the 180 temp. It will run 195-200. On pump gas it ran 200-215.

I'm wondering if I need even a little looser than the. .002ish when the coolant temp is 195+? Definitely thinking valve seals with the spring removed or no seals at all on the exhaust. I will take to the builder about this.

if it runs that temp no matter the t-stat then the radiator is too small or is not efficient enough. the stat will not make it run cooler only hold the temp higher. you have to remove more heat from the radiator so the stat will close some to maintain the heat in the block. is the radiator aluminum and if so is it natural? painting it black will help it some but there are limits and sometimes you have to go up in size or increase the air flow.

Quote:

Originally Posted by underpsi68 (Post 4682084)

Now I'm more confused with the cooler vs hotter coolant temps lol.

This is on a street turbo build. I have warmer block temps but also a lot hotter exhaust valve when in boost.

Just think of it as common sense. Cooler, oil is thicker. Hotter, oil is thinner. (Viscosity) Oil temps can dictate clearances through the whole engine. Just like closed cooling engines clearances are different than that of a raw water cooling in the marine world. That's why you typically can't take a performance automobile engine and stick it in a boat and expect it to last. Auto temps tend to be constant with consistent oil temps. When I first started boating and building boat engines I remember my bearing etc clearances being on the edge. Slightly more than marine spec. Machine shop I used, use always kept my marine builds slightly above marine spec and I would worry, but think about it. I always ran 20/50 and ran 10 pds oil pressure per 1k rpm. Would change a little depending on how hard and long I was running. Never ever a problem. But again I run in cold water in NW Michigan. Just saying.. for what ever it's worth.

Quote:

Originally Posted by sutphen 30 (Post 4682015)

a little loose on the intake,I use .0015"

We have found that .0015 is marginal , your guides and valves better be perfect or your gonna hang one .
Several hundred sets of heads and no detrimental effects yet.

From mercruiser racing manual; 1075/1200sci valve guide clearance range .001-.0025. Service at .003 Does not specify intake or exhaust.

Quote:

Originally Posted by 14 apache (Post 4682234)

From mercruiser racing manual; 1075/1200sci valve guide clearance range .001-.0025. Service at .003 Does not specify intake or exhaust.

I completely get the service at .003 but I'm struggling a bit on the "RANGE". How would one interpret .001-.0025? I would think it would be cut and dry. What do you make of it? Just curious.
john

Quote:

Originally Posted by dunnitagain (Post 4682134)

We have found that .0015 is marginal , your guides and valves better be perfect or your gonna hang one .
Several hundred sets of heads and no detrimental effects yet.

intakes aren't usually the problem,exhaust is.once the exhaust hangs,its sucking water and no matter what clearance you have,,your done.unless your totally dry.

Quote:

Originally Posted by getrdunn (Post 4682249)

I completely get the service at .003 but I'm struggling a bit on the "RANGE". How would one interpret .001-.0025? I would think it would be cut and dry. What do you make of it? Just curious.
john

My guess is closer to low .001s on intake and close to 002 on exhaust. .0025 the valve will move a tone and valve job won't last as long. I would not go over .002 on exhaust.

Quote:

Originally Posted by 14 apache (Post 4682024)

https://www.yellowbullet.com/forum/s...t=724514&amp=1

You will have to copy and paste its got good info for u

Thanks for the link Erik. Some good info there.

Quote:

Originally Posted by compedgemarine (Post 4682095)

I'm aware my coolant system could be bigger when the air temps get 90*+ when I sit in traffic. Problem is I have the largest radiator I can fit and the most powerful fan I could find (5000cfm). I just ran out of real estate. Now put twin turbos under the hood. No room and a lot of heat.https://cimg2.ibsrv.net/gimg/www.off...40a91b6fe7.jpg