My 454 Rebuild

Spareparts · Feb 5, 2023

Got it running this morning and nothing changed as i suspected after getting a good steady vacuum reading.
Next weekend ill be taking the upper intake off and check the injectors as well as the valve covers and make sure all valves look to be operating properly
I did however get new Electric fans installed. Flex a Lite kit made for our trucks. The actual installation is not too hard and finished it up this morning and seems to be working good at keeping it cool. Hard to know for sure as highs are still in the 30s.
I also had about 30ft of some 2 size welding cable so it was time for a cable upgrade. Battery was 6yo Walmart that was getting weak but still working so a new battery and converted to top post.
When starting it spins over much faster now. I have enough wire left to run from the fuse connection by the battery to the fuse box on the drivers side.

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Piratehunter · Feb 5, 2023

Spareparts said:
Before i tore into it i bought a vacuum gauge and it showed i was wasting my time with putting a new chain/gears in as vacuum was a rock solid 19 inhg.

where on the manifold did you connect to for the vacuum gauge reading? just wondering for myself. thanks

BNielsen · Feb 5, 2023

Spareparts said:
Got it running this morning and nothing changed as i suspected after getting a good steady vacuum reading.
Next weekend ill be taking the upper intake off and check the injectors as well as the valve covers and make sure all valves look to be operating properly
I did however get new Electric fans installed. Flex a Lite kit made for our trucks. The actual installation is not too hard and finished it up this morning and seems to be working good at keeping it cool. Hard to know for sure as highs are still in the 30s.
I also had about 30ft of some 2 size welding cable so it was time for a cable upgrade. Battery was 6yo Walmart that was getting weak but still working so a new battery and converted to top post.
When starting it spins over much faster now. I have enough wire left to run from the fuse connection by the battery to the fuse box on the drivers side.

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

Nice to see another truck with the military top post adapters; I got them on my 6.5 and so far so good.
I'm intrigued to see how well the e-fans will work, I've debated e-fans for years to try and free up a few ponies and a few MPGs, only I was looking at the Flex-A-Lite fan rated for a Duramax (6500 some odd CFM) and upgrading the pusher fan in front to something like a 14-inch Flex-A-Lite Slim fan (3K some odd CFM)

Spareparts · Feb 5, 2023

@Piratehunter I hooked it into the PVC port.

@BNielsen Yeah, i am waiting to see also. My engine had the HD style fan clutch on it when i got it and i swear it never went to free wheel even in below 0 temps. The new HD style one i put on in August is almost as bad and a constant drag on the engine. It was bad enough i had to scuff up the water pump pully or it was squealing a little even at idle even with a new belt.
The Flex A Lite 280 fans are ratted for 5,500 cfm.

BNielsen · Feb 5, 2023

Spareparts said:
@Piratehunter I hooked it into the PVC port.

@BNielsen Yeah, i am waiting to see also. My engine had the HD style fan clutch on it when i got it and i swear it never went to free wheel even in below 0 temps. The new HD style one i put on in August is almost as bad and a constant drag on the engine.

My 96 has a Severe Service fan clutch and an S10 plastic fan; I think something is worn out though since the truck likes to run a but warmer than it previously did. Prior to something wearing though the truck would go from 215* taking off from a stop, and once the fan spun up it'd be down to 175* or 170* in a minute or two.

Spareparts · Feb 6, 2023

I have a 195 thermostat in mine. Later today ill post up some temp numbers. I do have it adjusted so right when the thermostat opens the fans come on.

Spareparts · Feb 6, 2023

Looks like the fans come on/off at 185.
They make 2 sensors. The one it comes with you poke into the radiator fins and the other you put in the hose or block someplace.
I think ill order the style that goes into the hose or block. Don't know if it's better or not but seems like it would be and then is it better in the block or hose?.

Spareparts · Feb 6, 2023

I'm at a loss on what to check next for this slight miss.
To recap what has been checked.
Today i pulled the upper intake and checked the injectors and wiring. Wiring is good. Injectors are all working using the clean at home method but they are less than a year old.
Vacuum is 19inhg and holds rock steady.
Compression checked today and all cylinders are reading 135/138, Slightly low but still within specs.
Replaced timing chain and gears. Cam was not and is not a tooth off.
All spark plugs appear to be firing good
Changed cap/rotor and some plug wires.
Changed map sensor.
Changed egr valve.
Cleaned Throttle body.
Engine has no funny noises, has good oil pressure, seems to have good power.
Probable did ten other things i can't think of.

So im wondering if a bent valve pushrod could cause this problem?
Thinking is, Just spinning it over with the starter it will not show a valve not opening all the way but running is when the problem shows up as a valve is not allowing a cylinder to breathe properly??
It's about the last thing i can think of as a possibility.
Any suggestions are greatly appreciated :help:

BeXtreme · Feb 6, 2023

Spareparts said:
I'm at a loss on what to check next for this slight miss.
To recap what has been checked.
Today i pulled the upper intake and checked the injectors and wiring. Wiring is good. Injectors are all working using the clean at home method but they are less than a year old.
Vacuum is 19inhg and holds rock steady.
Compression checked today and all cylinders are reading 135/138, Slightly low but still within specs.
Replaced timing chain and gears. Cam was not and is not a tooth off.
All spark plugs appear to be firing good
Changed cap/rotor and some plug wires.
Changed map sensor.
Changed egr valve.
Cleaned Throttle body.
Engine has no funny noises, has good oil pressure, seems to have good power.
Probable did ten other things i can't think of.

So im wondering if a bent valve pushrod could cause this problem?
Thinking is, Just spinning it over with the starter it will not show a valve not opening all the way but running is when the problem shows up as a valve is not allowing a cylinder to breathe properly??
It's about the last thing i can think of as a possibility.
Any suggestions are greatly appreciated

I'll suggest the same thing I have suggested two times before.

Run a leakdown test.

Takes the same amount of time(or less) as the compression test you have now run three times and would tell you why you have low compression. Could be leaky valves, could be a crack somewhere, could be poorly adjusted valvetrain.... could be lots of things. Leakdown test will help you narrow down if you have a problem and where that problem is so that you can move forward. Right now you are just going in circles.

BeXtreme · Feb 6, 2023

Spareparts said:
Looks like the fans come on/off at 185.
They make 2 sensors. The one it comes with you poke into the radiator fins and the other you put in the hose or block someplace.
I think ill order the style that goes into the hose or block. Don't know if it's better or not but seems like it would be and then is it better in the block or hose?.

Since you already have the 0411, why not use the ECU to control the fans? Its a simple three relay system to get it to run a low/high speed setting and be able to adjust the set points in the tune.

My 454 Rebuild

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Piratehunter

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BNielsen

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