Novice seeking help (wiring/engine rebuild)

[Amsterdamned96]

Are there any threads on disassembly of pre ‘96 GMT400 interiors?

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[Dogged365]

I see a 6k tach and high mph speedometer.... is this a 454SS truck....

 

[Amsterdamned96]

I see a 6k tach and high mph speedometer.... is this a 454SS truck....

SW K3500 with the 7.4 with MPFI. So no, not a 454SS. The previous owner did have some work done on it & it had 502 valve covers so I thought it was a performance build, bore is standard 454 though.

 

[Erik the Awful]

When I pulled my dash, I followed this video. He has some good tips, but he skips some stuff.

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Don't pull the dash until you have all your parts ready to go in. I pulled my dash, ran into an issue, and had to wait a week to reassemble. I'm pretty sure I got a couple bits back together wrong. Then, as I was reinstalling, I discovered a handful of wire nuts on the door harness. Oh well, I'll fix that next time.

 

[Amsterdamned96]

When I pulled my dash, I followed this video. He has some good tips, but he skips some stuff.

xc_hide_links_from_guests_guests_error_hide_media

Don't pull the dash until you have all your parts ready to go in. I pulled my dash, ran into an issue, and had to wait a week to reassemble. I'm pretty sure I got a couple bits back together wrong. Then, as I was reinstalling, I discovered a handful of wire nuts on the door harness. Oh well, I'll fix that next time.

Thank you!
I appreciate your concern, I'm most worried about the retainer clips & longer pieces of moulded plastic.

 

[Amsterdamned96]

I’m waiting on a GM replacement terminal kit and for the cold weather to blow by before I continue the dash-disassembly. I’m trying to decide on wether or not I need to hone the engine. There’s still a visible 45 degree cross hatch on the cylinder walls, should I splurge some engine oil on them and see wether or not it adheres to the cyl. walls? I’m also considering putting the engine back together with the current bearings so that I don’t have to break it in again. I’m doing all of this in attempt to save money, my initial idea was to replace bearings, rings as well as gaskets. Now I’m considering doing bare minimum and just doing gaskets. Then getting the MPFI and computer working properly and potentially rebuilding the engine properly when the wiring & injection system is working properly. Please let me know your thoughts.

 

[Schurkey]

There’s still a visible 45 degree cross hatch on the cylinder walls, should I splurge some engine oil on them and see wether or not it adheres to the cyl. walls?

Pointless.

Do you see the honing marks ALL THE WAY from top to bottom of the cylinder? If so, MAYBE you could get by without cylinder-wall work. When that was me, I ran a *********** brush in 320 grit on the bores. Simple, easy, fast.

I’m also considering putting the engine back together with the current bearings so that I don’t have to break it in again.

If the bearings and journals are good, there's no reason not to re-use the bearings.

However, it's not the bearings that need to "break-in", so you're not saving any break-in time by reusing them. It's the rings, and flat-tappet cam/lifters that need break-in.

I’m doing all of this in attempt to save money, my initial idea was to replace bearings, rings as well as gaskets. Now I’m considering doing bare minimum and just doing gaskets. Then getting the MPFI and computer working properly and potentially rebuilding the engine properly when the wiring & injection system is working properly. Please let me know your thoughts.

What were your compression test results, and your cylinder leakage test results before you tore the engine apart?

If you have good compression and acceptable leakdown, good oil pressure, and the engine didn't burn oil...there'd be little reason to change rings and bearings.

If you didn't test cranking compression and cylinder leakage before it came apart...you'll know better next time.

 

[Erik the Awful]

If the bearings aren't worn funny, gouged, contaminated, or showing brass, and I was deliberately going as low-buck as possible, then I've reused bearings in other motors. I understand the shipping prices are high to Spain, but here small block Chevy bearings are so cheap that there's absolutely no reason to reuse them.

If you can still see the crosshatch in the bores, I wouldn't bother honing.

I did rebuild a 472 Cadillac with just a pair of head gaskets, a new oil pan gasket, new crank and rear main seals, reused valve cover gaskets, and a reused metal intake manifold gasket. Everything else was RTV. The engine ran fine except for the crankshaft tapping the home-fabbed oil pan.

 

[Amsterdamned96]

Pointless.

Do you see the honing marks ALL THE WAY from top to bottom of the cylinder? If so, MAYBE you could get by without cylinder-wall work. When that was me, I ran a *********** brush in 320 grit on the bores. Simple, easy, fast.


If the bearings and journals are good, there's no reason not to re-use the bearings.

However, it's not the bearings that need to "break-in", so you're not saving any break-in time by reusing them. It's the rings, and flat-tappet cam/lifters that need break-in.


What were your compression test results, and your cylinder leakage test results before you tore the engine apart?

If you have good compression and acceptable leakdown, good oil pressure, and the engine didn't burn oil...there'd be little reason to change rings and bearings.

If you didn't test cranking compression and cylinder leakage before it came apart...you'll know better next time.

I’ll do a thorough inspection of the cylinder wall and post a photo today. I’ll have to do some studying as I don’t know what the/a flat-tappet is. I’ll be re-using my cam & lifters. (Off-topic: I’m having a hard time finding a valve spring compressor large enough for the stock springs)

The results from the compression test were consistent for all 8 cyls. I’ve stupidly enough lost the sheet with the numbers and destroyed the motherboard of the phone that a copy. Cylinder 2 had a compression of 108 psi about 12-22 lower than the rest if my memory serves me right. This is most likely due to the spark plug thread being stripped (the plug wobbles in the hole). I’ve got a 14mm tap and helicoil kit.

I didn’t do a cylinder leakage test, sadly enough. I’m assuming this is to verify that the rings are in good shape? If all goes well with the wiring job & I plan on doing more work on this truck. Assuming I’ll have more money in the future, I’d also like to do more to this 454.

 

[Amsterdamned96]

If the bearings aren't worn funny, gouged, contaminated, or showing brass, and I was deliberately going as low-buck as possible, then I've reused bearings in other motors. I understand the shipping prices are high to Spain, but here small block Chevy bearings are so cheap that there's absolutely no reason to reuse them.

If you can still see the crosshatch in the bores, I wouldn't bother honing.

I did rebuild a 472 Cadillac with just a pair of head gaskets, a new oil pan gasket, new crank and rear main seals, reused valve cover gaskets, and a reused metal intake manifold gasket. Everything else was RTV. The engine ran fine except for the crankshaft tapping the home-fabbed oil pan.

Thanks for your 2 cents, I’m waiting on a harmonic balancer puller so that I can continue the teardown and inspect the bearings, cam & crank. Like I said I’ll post a picture of the cylinder walls.

You’re fabricating oil pans in house?! Oh the envy..