Highest CHT allowable for decarbon?

[sigintel]

Anyone run a colder thermostat like 170 Reische and have lots of very short trips around town?

I have a Reische 170 but have carbon in exhaust and pulled plugs to see some carbon with the boroscope and figured I was coking pistons and cylinder head alike with colder running. I didnt have one of those super bad ass scopes that can look upward at the the heads, only down towards pistons. I have like worst case usage of mostly short trips where I am only slightly up to temp getting out of subdivision then make constant pulls till exiting like 3 miles later and idle down after exiting to park in short order.

So with an up coming road trip I switched back to the Whipple Motorad thermostat where I could get the temps up to 238 CHT or higher.

Car is always driven hard and the trip was no exception. I noticed slightly less power with the higher temps and seemed to have picked up a light rasp/rattle in one of the cats (prolly cracked but expected to happen, lol).

Anyone have a max extended use track CHT they have run without instant head gasket weeping?

Should I go further or is 235-240F CHT indicated prolly best effort?

Dont WANT to change head gasket, but if pistons, plugs and heads are lined with carbon, then the heads have to come off to clean that out.
If not I guess I risk losing the motor to detonation?
or simply the Whipple tune will pull all the power due to constant detonation?

edit* cylinder 8 was cleanest. 5000 miles, lifetime mpg ~12.5 including 3x 500 mile road trips.

Whipple, whats yalls max continuous CHT with motorad this summer?

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[F1scamp]

Uummm.. I wouldnt intentionally try to get hotter than 238 cht. If you are having a carbon build up issue i would try to fix the issue. Let it get up to temp every trip, catch can of some sort, better quality fuel, better quality oil... If it is carboned up, seafoam the crap out of it and a new set of plugs.

 

[smokinzx14r]

No need to take anything apart to clean the carbon ... First off start with good fuel ( Shell ) Next run some techron now and then , the techron will clean the valves and pistons and look like new again .. It's also good for your injectors .. Seafoam will also do a good Job and you can pick that up at a Napa store ..

 

[sigintel]

Are there any thermostats like the Reische 170 that are less linear and open more per degree vs the Reische?

Like a Reische 180 but with a large diaphram?

Dunno.
[MENTION=14278]smokinzx14r[/MENTION] Always run Chevron 93 from a traffic/turnover gas station nearby (pass on way in out of my hood). Shell is next then Exxon but I have never put Exxon in. PS, Used to run a 91 ZX-11 when I lived in Davis Mountains of West Texas on the edge of Chihuahuan Desert.
[MENTION=24357]F1scamp[/MENTION] Thats the exact problem, lol. Problem is getting up to temp every trip. The trips are so short and I just cant stay out of the gas. lol.. I need a new super hybrid thermostat that is 100% shut hard and then just wide open after 190.
or Maybe a block heater?

I just cant stay out of the gas. Maybe need "professional help".

@all We aren't at "seafoam" levels of carbon build up. Its pretty light. Seafoam is a last resort as I have seen some light metal etching using that in the past and on the farm. Very hesitant to use it on sintered particle metalurgy where I have seen it leave really rough surface that looks like sanded EPE styrofoam where the grain boundaries end up raised.
I might just have bad seafoam procedure: get hot as possible, seafoam the crap out of it.

 

[Whipple SC]

You can put in a stock GT350 180 stat if you want more temp, but I wouldn't advise it.

Remember coolant temp and cylinder head temp are 2 different things, they run roughly 25-30deg different from eachother. Most thermostats run 15-20deg over the rated temp as they start to open at the rated temp. CHT's around 210-220 is normal and not a problem in summertime. Peak combustion efficiency is around this temp range.

 

[sigintel]

Thanks for thoughts.

220 is normal for crusing in traffic?
Or after doing 6 back to back highway pulls?

We were seeing 205 tollway w AC on at 85mph (legal on tollway). State trooper uncle was driving and it took very little to get above 235 or hit 240 CHT indicated.

Getting off highway after pulls was not good.

Really seems like water pump needs more RPM and engine bay needs way better ventilation for radiator.

Ill put Reische 170 back on to see if it goes back to 190 with max 225 while pushing it. If not the same again, then something changed or head might have an intermittent leak.

 

[Barrel]

You sure your coolant level is good?

 

[GTBOB]

OP, are you running any sort of catch can?

 

[sigintel]

OP, are you running any sort of catch can?

No catch can. Guess its time?
Oil level has been perfect so if there is vapor there hasn't been much.
That being said, I guess I should have guessed that was more likely cause of carbon than low temps.

 

[Super Werty]

With no catch can I bet your intercooler is caked in oil

 

[Barrel]

Wow yeah no catch can is no bueno without breathers.

 

[sigintel]

Think a 100 wet shot at TB would clean it out? (not serious)

If I pull plugs and run a whole can of carb cleaner thru the TB while cranking the engine every now and then, It should be fine yes?
Just wash it down and pump it into the exhaust without liquid locking a cylinder...?

 

[F1scamp]

Please dont. Grab a can of sea foam and use it per the directions. All healthy street motors will have some kind of oil presence on the pistons, if you dont think it is excessive, dont worry about it.

It's your car, but not for nothing, you shouldnt be beating on it until it is up to temperature.. Even if you start it and let it idle a couple mins will help it out.

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