Chevy 454

[sc3283]

Originally Posted by WeatherTodd

not sure why you chose a 160 thermostat... but heat is heat.you wont notice a 20 or even 40 drop in thermostat temp.

I beg to differ!

I chose the cool T stat to help eliminate the severe underhood temps...after an uphill pull the exhaust manifolds were glowing beyond red prior to the t stat change...after the change...I never saw the faintest glow of red on exact same hills at exact same temps

[Mike Thomas]

I had a 1995 Winnebago Adventurer with 454 TBI. It ran like a race horse. It kind of had a "dead spot" from about 55mph to 62 mph, but once you got past 62 mph, no problems. I could run that thing all day at 70 to75 mph.

It was very noisy when I accelerated, almost to the point that you couldn't talk to the passenger. I found that most of the noise was coming up through the carburetor. I got my JC Whitney catalog out and purchased some sound deadening material. It was about as thick as a piece of courugated cardboard and self adhesive after you peeled some plastic off one side. I applied it to the top of the air cleaner, and the snorkle from that up to the front of the engine. That really quieted it down.

Then I started to pull a 16 foot enclosed trailer with my Model T. Total weight about 3500 pounds. That is when it would heat up, crack manifolds, burn off spark plug wires, etc. Fuel mileage dropped from 7.5 to 5.5 while pulling the trailer. Talked to the folks at Braezels, (they post on the forum here). He sent me a "chip", I added one of those cooling kits that bring fresh air from the grill and dump it on the passenger side manifold, and added those heavy spark plug wires. It did not burn spark plug wires off anymore. It would still crack a manifold once in a while. The "chip" brought the fuel mileage back up to 7.5 while pulling the trailer, and gave it a lot more power, and much better overal driveabliity. I thought it was well worth the money.

If I had not been pulling a trailer, I probably would not have had any problems, other than the noise on acceleration. I drove the heck out of it, and it held up well. I sold it last fall and bought a DP, just for the comfort and extra towing capacity.

An old friend of mine used to live out in Nebraska where they irrigate. He said that they used that engine on irrigation pumps. He said that many times they would take a brand new engine out of the crate, bolt it up to a pump, start it and run at full throttle. He said they would run day in and day out at full throttle.

[WeatherTodd]

Originally Posted by sc3283

I beg to differ!

I chose the cool T stat to help eliminate the severe underhood temps...after an uphill pull the exhaust manifolds were glowing beyond red prior to the t stat change...after the change...I never saw the faintest glow of red on exact same hills at exact same temps

Should have clarified... I was talking about the "dash heat".

As for a thermostat cooling exhaust manifolds... Ill put it simple. Youre incorrect. Puting a 30 degree cooler thermostat tells the TBI computer to inject more fuel. More fuel = richer = cylinder temps = cooler.
Had you matched the thermostat to say a proper intake system and exhaust system... the additional fuel youre wasting would have gone to make more torque and hp.

[Gene1]

As to 'thermostat'...all 'experts' agree that 'cold engines' wear
cylinder walls much faster and thus need higher degree
thermostats. In cold climates, warm up is necessary, as
alum. pistons expand faster than cast iron blocks, to
put a cold engine under heavy load, can and will
scour cylinder walls. Also, with Alum. heads, which,
when heating, expand, and move horizon-ly on cast
iron block, need warm up. Never remove spark plugs
from a hot alum. head.: (exception to all this..some of
the latest cars out, have very much reduced the space
between pistons and cylinder, demanding almost water
thin oil. They heat up very fast, because small engine
that is 'overworked' has to. Their non pure alum. pistons
have additives that keep them from expanding.)

[Gene1]

Another quick thought, On hot manifolds..thin
stainless steel ones do turn red, under right
conditions. Three things will cause red hot
iron manifolds. Smog pump that inserts air
into manifold, not working, Spark plugs firing
to far before piston is at the top, and engine
lugging..with new computer controls and
automatic transmission should take care of
these problems.

[sc3283]

Experts....1st off the early 90s 454s didnt have alum heads.
2nd off, while the thinking of wasted fuel ect due to a cold engine makes sense BUT you have forgotten about the O2 sensor...the early 90s TBI EFI was not near as advanced as OBDII systems
3rd off early 90s 454s didn't have stainless exhaust manifolds..they were cast iron
4th off....13mph unloaded @70mph with either a 195 or 160 T-stat or 8.5 mpg towing @hiway speeds with either T stat indicates the O2 was doing its job...thus NOT wasting fuel.
5th off as stated below 50 degrees ambient temp...dash heat was poor and mpg was poor due the engine not being able to produce enough heat to overcome the radiator doing it's job

So while some of the above comments are true...Gene and Todd....how many early 454s have you owned and how in depth are you with your experience with the 454?

If you 2 were as knowledgable as your trying to make yourselves appear..you'd know 1st had that most all early 90s 454 did not have a cooling system capacity that had the ability to keep the 454 cool in summer temps....

And the 454 I'm describing/discussing.....21 year old this year....never has had a valve cover or cylinder head or oil pan removed...so it is possible there may be some validity to the comments I have made??????

So now back to the original question of this thread?

[WeatherTodd]

Originally Posted by sc3283

Experts....1st off the early 90s 454s didnt have alum heads.
2nd off, while the thinking of wasted fuel ect due to a cold engine makes sense BUT you have forgotten about the O2 sensor...the early 90s TBI EFI was not near as advanced as OBDII systems
3rd off early 90s 454s didn't have stainless exhaust manifolds..they were cast iron
4th off....13mph unloaded @70mph with either a 195 or 160 T-stat or 8.5 mpg towing @hiway speeds with either T stat indicates the O2 was doing its job...thus NOT wasting fuel.
5th off as stated below 50 degrees ambient temp...dash heat was poor and mpg was poor due the engine not being able to produce enough heat to overcome the radiator doing it's job

So while some of the above comments are true...Gene and Todd....how many early 454s have you owned and how in depth are you with your experience with the 454?

If you 2 were as knowledgable as your trying to make yourselves appear..you'd know 1st had that most all early 90s 454 did not have a cooling system capacity that had the ability to keep the 454 cool in summer temps....

And the 454 I'm describing/discussing.....21 year old this year....never has had a valve cover or cylinder head or oil pan removed...so it is possible there may be some validity to the comments I have made??????

So now back to the original question of this thread?

yes I owned a 454 TBI powered chassis for 2yrs. Took me all of 1 month to figure out cast manifolds werent doing anything good for me.
Though 13mpg claims are as unbelievable as they come since Ive seen the same drivetrain in pickups barely get that.
My 1998 rig had plenty of radiator realestate (width and depth) to keep my 17k rig at the 180 degree mark with or without a trailer. Other than flushing the death cool and replacing a broken radiator drain plug... cooling system gave me zero issues in 20k+ miles up and down the east coast and humid FL summers. Of course I have a fundamental understanding of how to correctly mix coolant versus the operating climate. (hint 50/50 isnt the best)
And Im not a proclaimed expert... just questioning your perception.

My original reply was to your claim about "dash heat" not getting up to temp. I replied to the fact you couldnt tell the difference between 200 degree or 160 degree coolant.

[sc3283]

Once again...stay on topic with the OP's questions....98 454 was a Vortec..not TBI....totally 2 different injection designs and 2 different engine designs, with different water flow through engine block and heads...90s model 454s were MKIV, MKV, and MKVI....while all producing 454 cu.in..all were different in many many ways

[Xpoint]

sc3283, Two questions for you. My 454 is in a 94 MH. Do you consider this an early 90's model. Second, did the 454 you are refuring to have the cooling system completely flushed out? Do you think that would make a difference?

[campclan]

My father has 94 Bounder with a 454. He has had pretty good luck with it. He noticed at idle sometimes the check engine light would come on. After driving for a few minutes light would go out. Eventually got around to replacing the o2 sensor as that was the culprit. He has put about 70,000 miles on it since he bought it.

When he 1st bought it had around 35,000 on it so we flushed the radiator and tuned it up. Also replaced one of the injectors. At 100,000 just did a major tune and another cooling system flush and it runs like a top. Never had any issues overheating. He has been averaging 7.5-8.0 mpg when towing or not.

Good luck.

[Gene1]

not to brag...but I did work as a Mechanic, since 1952, I have seen many changes,
way before torque wrench's, aluminium heads, and a lot of other things. I even
remember setting points! I retired as a journeyman. Yes, I have a 454, I also have
a V10...(in my spare time, I had a coin laundry 40years. so, yes, I can speak as
to experience, although I don't claim to be an 'expert'..call me what ever you want.
you're on your own, from here on out...gene

[WeatherTodd]

Originally Posted by sc3283

Once again...stay on topic with the OP's questions....98 454 was a Vortec..not TBI....totally 2 different injection designs and 2 different engine designs, with different water flow through engine block and heads...90s model 454s were MKIV, MKV, and MKVI....while all producing 454 cu.in..all were different in many many ways

wow... you really are clueless.

[sc3283]

Xpoint....the 454 I speak of I bought new. It never had a dirty cooling system. Coolant flushes while good when a system is clean and it is done to just remove old coolant and replenish with new is fantastic. Coolant flushes done in an effort to remove muck and crud and corrosion do very little in the way of a true cleaning. Chemicals harsh enough to eat away tough corrosion and crud will and do eat away at useful items as well (ie heater cores, head gaskets, intake gaskets, etc)

Todd check your 454 facts...2 versions of EFI in the 90s and 3 versions of engines...and all were 454 cu in

As asked prior...now that some have tried to flame others...can we get back to the OPs original topic??