Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Topic: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87 (Read 3370 times) previous topic - next topic

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #25 – September 23, 2017, 11:46:36 pm

Is this coach rear engine or front? Maybe add independent tranny cooler with fan. If rear Engine use the heater hose lines and add a radiator at the front with fans from a salvaged 4 cylinder car. Check the seat in the radiator neck where the cap rubber valve seals too. How much do you weigh? if irc you emptied your house or apartment into the coach.

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #26 – September 24, 2017, 12:23:10 am

I build single cylinder dirt bike four stroke engines and their carbs.

Yours sounds lean. Hot. Less power?. Good gas mileage?.

Rebuild carb?. Have someone check the air to fuel ratio,

Too much advance on timing. Or lean.

Any chance exhaust blocked?

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #27 – September 24, 2017, 09:45:47 am

Quote from: Old phart phred – September 23, 2017, 11:46:36 pm

Maybe add independent tranny cooler with fan.

Building on phred's suggestion, you could also consider fitting a external engine oil cooler. These are commonly used on hard-working engines in all sorts of venues. Engine oil doesn't just lubricate - it also helps cool the engine. A good quality oil cooler would be size matched to the engine displacement, and controlled by a thermostatic valve that only opens when a certain oil temp is reached. There are many types/configurations.

Links below to some websites for more info:

Guide To Engine & Transmission Oil Coolers | Medium Duty Work Truck Info

Derale Performance | The leader in performance cooling!

http://www.haydenauto.com/featured%20products-transmission%20and%20engine%20oil%20coolers/content.aspx

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #28 – September 24, 2017, 11:12:42 am

Like Bob says. 1) Check timing , reduce the lead 3 degrees. regardless of where it is.
2) Oil cooler may drop it 5 *
3) Synthetic oil will drop it a couple. Plus wont burn/coke the oil.
4) Check or change the water pump . often they look like new but the fins are missing or reduced.
5) The rad coolant return line should show 20 or more * of heat loss. The headers and manifolds can radiate heat back into the coolant hose if they are close. The IR heat gun will show if that happens.
6) Add or check for rad shrouds being in place. Plug the gaps around the radiator .
My P 30 put down many miles without getting overly hot @ 18K #

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #29 – September 24, 2017, 12:04:47 pm

You need some fans like these: ELECTRIFYING THE FUTURE AT PREVOST | Prevost

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #30 – September 24, 2017, 01:48:25 pm

Is there anything that can be added to coolant to improve heat transfer?
I think proper mix of water and antifreeze is important for heat transfer.

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #31 – September 24, 2017, 02:37:14 pm

I run a 60% water 40% delo ELC which gives a greatly improved heat trqnsfer over normal green coolant and over a 50/50 elc mix. Lowers the freeze protection to -15f but I know my engine will never see those temps in my climate or anywhere I will ever go. Really helped with temps creeping up on long hill climbs.

I think you have many issues, most likely would benefit from a new larger radiator and clean core, even if flushing produced clean water the tubes could be clogged preventing the flush from reaching them. You need a methodical troubleshoot by a pro to get this thing going! Even timing or fuel mix could be the cause. Clogged secondaries causing a lean condition climbing hills? Bad timing advance? Bad base timing? So many possibilities.

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #32 – September 24, 2017, 03:23:31 pm

Quote from: John Duld – September 24, 2017, 01:48:25 pm

Is there anything that can be added to coolant to improve heat transfer?
I think proper mix of water and antifreeze is important for heat transfer.

Water wetter, reduces surface tension of water molecules so they are more easily stripped from Surfaces

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #33 – September 24, 2017, 03:33:58 pm

I think you've solved your own problem. If you don't have coolant returning to the radiator from the expansion tank it will over heat from loss of coolant. Fix that first and add a new radiator cap just for the helluvit cuz they're cheap. And the 180 thermostat for a 454 as previously mentioned. Also cheap.

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #34 – September 24, 2017, 05:36:44 pm

Before you spend a lot of money on stuff that may not need replacing, take the thermostat out, go for a drive up some hills and see if that fixes the problem. Today's thermostats are junk even when brand new. If the engine doesn't overheat with the thermostat removed, buy a bunch of new thermostats, take them home and put them all in a pot of water on the stove and boil them. Watch carefully to see which thermostat opens first. Install that thermostat and get rid of the others... Please don't return them to the parts store for some other poor unfortunate person to install in their engine!

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #35 – September 24, 2017, 08:27:38 pm

That 454 does not like being so hot that it doesn't run. Cylinders will get egg shaped, so need to fix it sooner than later or you will be replacing the engine and that is a real problem on a front engine chevy chassis.

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #36 – September 24, 2017, 10:13:53 pm

Don't run with no thermostat. The water moves too fast for adequate heat transfer. Cut the venter out of the thermostat so that the outer disc is intact. This is the required amount of fluid restriction. Even on race cars with out the thermostat we either cut a thermostat apart or ordered a restrictor in.

Another option is an electric waterpump. Pump speeds up and slows down based on the temp sent to control module. We are still experimenting with it in the new race car.

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #37 – September 24, 2017, 10:57:21 pm

Bottom line I had an 89 P30 454 SOB nothing special done to it, towing a 20' trailer full of motorcycles all stock never got close to running hot. Got to be something wrong. Gm designed it to work without all the extra fans and so on. JMHO

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #38 – September 24, 2017, 11:20:50 pm

Whenever I have a thermostat fail I remove it and don't replace it until winter. I've never had an engine overheat without a thermostat. Quite the contrary, it takes forever for the engine to warm up properly, if it ever does. That's the major danger to running with no thermostat, that the engine won't get warm enough to boil off contaminants and sludge will start to build up as a result... but he just needs to remove the thermostat for testing and then find a working thermostat to replace it with... (good luck) ...and if you have a thermostat that works don't ever replace it because you'll have a tough time finding another one that works properly. Go get a few from the local parts store and boil them on the stove to see for yourself how poor the quality is today.

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #39 – September 24, 2017, 11:30:53 pm

Quote from: RRadio – September 24, 2017, 11:20:50 pm

I've never had an engine overheat without a thermostat...

Hmmm, neither have I...

BBeane, did your SOB have an auxiliary oil cooler?

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #40 – September 24, 2017, 11:50:44 pm

For the trans only( turbo 400), and it was likely aftermarket. Got the old thing on a trade it was a National Dolphin, ran the stuff out of it for 2 years.

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #41 – September 25, 2017, 12:21:21 am

Quote from: its toby – September 24, 2017, 10:13:53 pm

The water moves too fast for adequate heat transfer.

Say what? Better examine the proven eqautions, in typical non overheating mode this may appear to hold true as the delta temps go down on one side. Total bs when overheating.

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #42 – September 25, 2017, 10:45:39 am

Install an intake manifold vacuum guage.
Check for timing chain stretch.
The vacuum guage will help with any diagnoss of timing / fueling issues.

Is this a carbureted or throttle body engine?

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #43 – September 25, 2017, 11:00:17 am

Do we know if this is an all of a sudden issue, or a long term problem? Makes a difference in where to start looking.

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #44 – September 25, 2017, 02:17:21 pm

The only 454 I ever liked, was a buddy who had it in his 1/2 ton pickup with stick shift. You did not want to race that guy!

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #45 – September 25, 2017, 04:59:18 pm

Driving while overheating until the engine loses power is a sure way to have to replace it. Have you checked for products of combustion the the coolant? The symptoms you describe are exactly the same for a improperly torqued head or a damaged head gasket. I bought a 3.4 Jaguar with a custom rebuilt 327 in it. The previous owner spent a fortune with new radiators, etc but it still overheated at anything above an idle. I just torqued the engine to specs and then drove it for years. But, I never let it get a hot as you describe.

A radiator shop can check for products of combustion or you can easily do it yourself with this kit: Amazon.com: UVIEW 560000 Combustion Leak Tester: Automotive

Pierce

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Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #46 – September 25, 2017, 09:45:00 pm

That coach has a carb.

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #47 – September 26, 2017, 11:08:22 am

Seems as the OP is missing.

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #48 – September 26, 2017, 11:36:12 am

Probably overwhelmed with all the suggestions. Remember he is full timing with kids.

Re: Overheating Help: FT GV with Chevy 454 on P-30 Chassis '87

Reply #49 – September 26, 2017, 09:19:56 pm

op is new to this unit so likely doesn't have a history on how long its been overheating. he could be fighting old damage.

as for the water restrictor we run 454s punched to 468 on the circle tracks and through testing as well as testing the engine builder has done no restrictor runs hotter. some where I used to have a gm tech bulletin about it too but these days I cant find a receipt from last week let alone a bulletin as old as I am.

you have a lot of suggestions to go through, really it all comes down to doing a complete step by step check of the whole system. be sure to make sure you are actually getting heat transfer check water temp into and out of the engine and the radiator. make sure the water is actually cooling in the rad. over heating could have caused the rad tubes to swell. they can swell to the point of touching each other which means no airflow through the rad and no cooling of the fluid.

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