Valve guide clearance question
 

What valve guide clearance are you guys running for boosted combos on high hp marine builds? 11/32"

Had some issues with my turboed street car and was wondering if the clearance was too tight for my application.

Exhaust valve https://www.cnc-motorsports.com/ferr...600-11-32.html

yes

I have also heard some run the seal without the spring to allow for better lubrication.

Not sure on the finish. I attached a few pictures from when I just disassembled. 6&7 exhaust valves were very tight in guide when I disassembled. On a sbf those are the center cylinders on the left bank.https://cimg5.ibsrv.net/gimg/www.off...198063b214.jpg
https://cimg7.ibsrv.net/gimg/www.off...28847b7a7e.jpg
https://cimg9.ibsrv.net/gimg/www.off...6a2599a5b1.jpg

who's cylinder heads?may have cheap guides in there.may have to switch them out for the higher end guides or your gonna have to loosen them up a bit more.

I wish I knew. I will know this time for sure.

.002 Intakes ,,, .0022 Exhaust Minimum

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

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.

Agree, I set mine .0020 Intake and .0022 exhaust on my heads..rarely see more then 110-120 water temps.

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.

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.

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.

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.

Thanks for the link Erik. Some good info there.

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

painting the radiator black will help some. it has been tested before for heat load and the same radiator painted black transferred more heat than the same one left aluminum. what fan are you running? I have seen plenty that were rated at "x" cfm but did not really move that.

Have you tried going back to a belt driven water pump and factory fan? I been modding Mustangs for 23 years or so, had some huge power cars that ran cool still with the factory fan, it moves a TON of air..had a few buddies fight your issues and deciding to go back to factory setup and cools great. just a thought to try, BTW I love seeing hot rod Fords! hell even my 94 cobra uses the factory tiny radiator and fan and don't get hot with boost, and has A/C also.

Currently I do not, but am thinking of adding them and run the 8egts full time. I am looking into different brands right now.

I have never heard that with black paint, but will look into.

From my research years ago the Lincoln Mark VIII fan was the highest flowing fan available anywhere(OEM or aftermarket- there might be a higher flowing one now, not sure). The fan came in 2 configurations, one flowed 4500cfm the other 5000cfm. The earlier version flowed 5000 but Ford had complaints that it was noisy and redesigned it to be quieter, changing the blades losing air flow. It is an awesome fan. Factory reliability, but it is very power hungry. It will draw over 100amps at startup an pull 44amps while running. It is a 2 speed fan as well. I run mine with pwm with a soft start. I don't get the 100amp spike and it will run more efficiently using pwm. If my memory is still good I run it at 90%cfm and am only pulling 50% of the amps, about 22. Pwm works great. Been running it this way for over 15 years without issue. The amount of air this fan flows is incredible. Its 18".

Another very good fan that is right behind it is the Taurus fan. It also pulls 4500cfm being a 17". Again factory reliability and they both are cheap.

I have used a belt driven pump. Currently running an electric (in picture) that uses an idler pulley. It is a 55gpm pump. It will flow more at idle/lower rpms than the belt driven pump. Same for using the electric fan I'm running. Also running the pump on PWM to vary the speed and amperage draw. My temps issues are more at idle/ low speed due to not much air getting into engine compartment and a small front opening. I am running a 4" thick intercooler that is as big as I could fit. Than I have 2 transmission coolers blocking the top of the radiator (as well as a frame mounted transmission cooler). It is hard to keep the tranny cool to make it last, especially with a high stall convertor. 10 years without any issues.

When you say high hp, how much are we talking? This engine will make 1000+, probably 1400 (possibly 1500) all in. It is much harder to keep a car cool driven on the street than a boat. I wish I had an endless supply of cold water lol. Also are you running a supercharger? Stock block? I ran Vortechs for about 20 years. The supercharger engine will run cooler than the turbo setup. Factory block will run cooler than my Ford "R" race block. Siamese bore with a lot more metal. Not much room for coolant. Lol Also possibly a big difference in traffic and air temps. Did I say I love NY?

I'm looking for a stand alone system that can monitor and datalog 8 probes of you know of any. Would like to have a gauge as well. Any recommendations there?