My 454 Rebuild

L31MaxExpress · Jan 15, 2023

Spareparts said:
Strangest this i have seen in a engine tear down was a Cadillac engine that had no rings on one piston and on a old Chevy 216 dipper someone used a leather strap for rod bearing.

Back about 2008 when I was with a Dodge, Chrysler, Jeep dealer a customers 4.7L Jeep with 30K miles started using coolant. We found that the factory never even put a head gasket on one bank.

Second was a brand new Challenger SRT. Would not back off the delivery truck. They never drilled the transmission case for the reverse line pressure to activate the reverse clutch pack.

Schurkey · Jan 15, 2023

"Dot-to-dot" is crap. You're relying on about five different machining operations all being done correctly, with little room for error or tolerance stack-up, and there's a reasonable chance that at least two of them are being done by the Communist Chinese. I won't put an engine together any more without "degreeing" the cam. I rarely ever have to "fix" a problem...but I also never have to deal with mis-timed cams as part of my diagnosis for driveability issues, either.

Verify cam timing. This is not a precise deal unless you install the whole dial-indicator-and-degree-wheel tool set; but you could maybe eyeball it to see if it's close.

Put the #1 cylinder on TDC-EXHAUST. (Normally, when you want TDC, you want TDC-Compression. This is not one of those times.)

Both valves should be open on overlap--just barely open. The intake valve should be open just a little more than the exhaust valve. This is easier to see on solid-lifter cams, because the lifters don't bleed-down. Give it a go, see what happens.

What was the piston-to-deck clearance? Excess piston to deck--often called piston "down in the hole"--will kill compression ratio and compression pressure. Worse, most aftermarket replacement pistons are deliberately "de-stroked" (a misleading term that has nothing to do with crank stroke) so they're an additional .010 or .020 "in the hole".

L31MaxExpress · Jan 15, 2023

Spareparts said:
That's a good idea! Have a link to the snap rings?

I don't unfortunately. I got them from my local Ace Hardware. I did take a picture of the box label. That is all that was on them, not even a brand name.

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L31MaxExpress · Jan 15, 2023

Schurkey said:
"Dot-to-dot" is crap. You're relying on about five different machining operations all being done correctly, with little room for error or tolerance stack-up, and there's a reasonable chance that at least two of them are being done by the Communist Chinese. I won't put an engine together any more without "degreeing" the cam. I rarely ever have to "fix" a problem...but I also never have to deal with mis-timed cams as part of my diagnosis for driveability issues, either.

Verify cam timing. This is not a precise deal unless you install the whole dial-indicator-and-degree-wheel tool set; but you could maybe eyeball it to see if it's close.

Put the #1 cylinder on TDC-EXHAUST. (Normally, when you want TDC, you want TDC-Compression. This is not one of those times.)

Both valves should be open on overlap--just barely open. The intake valve should be open just a little more than the exhaust valve. This is easier to see on solid-lifter cams, because the lifters don't bleed-down. Give it a go, see what happens.

What was the piston-to-deck clearance? Excess piston to deck--often called piston "down in the hole"--will kill compression ratio and compression pressure. Worse, most aftermarket replacement pistons are deliberately "de-stroked" (a misleading term that has nothing to do with crank stroke) so they're an additional .010 or .020 "in the hole".

I am right there with you after having had a cam that was nowhere near what it was supposed to be.

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Spareparts · Jan 16, 2023

Way back on post 126(pg13) has the info for piston hight. Was led to believe it's ok.
Thinking about it all day i just have to believe the cam is not right.

yevgenievich · Jan 16, 2023

This is just for reference: my recent built bbc with flat top pistons and slightly larger(113cc) than stock combustion chamber checked out at 180psi with compression tester.

Spareparts · Jan 16, 2023

Now that i think about it can only be 2 things i think.
Bad cam or.
The bottom part of my compression gauge, the hose that actually screws into the block could be bad although it is new but was used with 2 different compression gauges. You can see in the pic what im talking about.
Friday i will be checking it with a totally different gauge. If it checks good, great. If still reading 120psi i'll change the cam.

Piratehunter · Jan 16, 2023

Spareparts said:
Way back on post 126(pg13) has the info for piston hight. Was led to believe it's ok.
Thinking about it all day i just have to believe the cam is not right.

Dang I’m sorry you’re having this issue. If you have to open the timing cover to check gear alignment, hopefully the cam nose will have a part number on it, so you can validate what it is too.

Piratehunter · Jan 16, 2023

Spareparts said:
Now that i think about it can only be 2 things i think.
Bad cam or.
The bottom part of my compression gauge, the hose that actually screws into the block could be bad although it is new but was used with 2 different compression gauges. You can see in the pic what im talking about.
Friday i will be checking it with a totally different gauge. If it checks good, great. If still reading 120psi i'll change the cam.

I recall when I checked mine, I couldn’t get the short hose to seat all the way down into the plug hole. Used an adapter on one of the larger hoses to get to 14 mm. Not sure that is a problem for you.

Spareparts · Jan 16, 2023

Check post 207. The cam is listed as the right one. I think it was manufactured wrong but also possible it's a bad compression gauge.

My 454 Rebuild

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