New member, blown motor!

[Hoss]

Hey all,

I'm a new member. I have owned my 1985 C30 3+3 Silverado since March 2021. Found her online, fell in love, flew to LA, drove to the top of the NW with no problems besides a flat in Crapremento. It carries my camper in the winter and hauls our travel trailer and 3 boys in the summer. I replace parts as needed with US made, or at least not Chinese. I have replaced u-joints/carrier bearing, alternator, starter, battery with all new wires. Last week I ordered headers, intake and carburetor. Pulling our trailer to go camping last Friday I lost compression at 55 and the truck would not restart. Towed to mechanic and he reports that a scope of cylinder 1 shows a dinged piston and bent valve. He believes the timing got off bad enough that pistons and cylinders collided. I didn't know that was possible but he says 454's are interference engines. A second opinion mechanic doesn't think that is what happened, he thinks it more likely that a valve got stuck on build up and the slammed into the cylinder.
Needless to say I have to fix this one way or another. I love learning to work on this truck but some of the work required here may be beyond my capabilities with the tools I own. However I do love an opportunity to buy more tools, like say an engine hoist.
Tell me what you would do I you were keeping this truck for my purposes and wanted to pass it on to your children. Ideas I have pondered, fix the valve train and heads, possibly pistons but then can the bottom end handle the new compression for much longer. Buy a used or rebuilt 454 off craigslist and learn to drop it in myself? Or go for a reman long block from S&J or someone else and have a mechanic do the work for the 7 year warranty.

Thanks for your replies, please assume I know very little about these things,
Hoss

 

[dusterdude]

Welcome

 

[ali_c20]

Welcome from Austria. I would keep the engine if it's the original one. Fix it and make all needed modifications and you're good to go.

 

[Corvette Ed]

Welcome aboard from East Tennessee.

 

[pnwnvrdn]

Welcome.
I'd search out a reputable machine shop in your area, and have your engine rebuilt (long block), using quality parts.
As for doing the work yourself, sounds like you're up for it, so go for it.
Good luck.

 

[Soundmound]

Howdy neighbor! My vote if you want easiest/quickest, swap a crate in from a reputable company and roll on. Machine work, any labor really, is expensive in the Puget Sound area and who knows what the end result will be. Plus, what is your time worth per hour? It may be cheaper to buy vs. build it, especially wrangling three kids I would imagine.

 

[Catbox]

Welcome from Oregon!

For my truck and its 454, I will be rebuilding and installing a set of the L-29 Vortec big block heads for it.
Mine still has the low compression peanut port heads like yours probably does.
The sad 8.0 to 1 compression ratio is lack luster currently.

The Vortec heads offer a 100cc fast burn combustion chamber versus the 113 or so open chamber the peanuts offer. The smaller chamber size will bump the compression ratio approximately a point to 9.0 to 1. They also have larger intake runners than the peanuts for more flow.

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Just the head change is supposed to net a difference of 30-40 hp and similar torque from the internet research I have done.

These are the head gaskets that were recommended to use.

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I have pulled two sets of them out of the local Pick-N-Pull for $80 a set plus fees.
I am no master mechanic, but I am willing to learn and buy the tools needed for the swap like you are.

While we have it all apart, this Edelbrock Performer intake will find its way onto the engine instead of the stock iron one that comes off.

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Of course you can also have the peanuts rebuilt and they can be made to flow well for better performance in all RPM's as have been demonstrated on the forum as well as many others across the internets.

Before you make any decision, do loads of research to see what others have done. None of what you decide to do is going to be original, there are always examples of others work out there to see what has and has not worked.

Here is a great place to start reading up on things....

tips on building a peanut port big block combo

PEANUT PORT HEADS WITH RECTANGLE PORT GASKET ABOVE 346236 1975-87 454 Open 113cc .PEANUT SLIGHTLY LARGER, COMMON EARLY OVAL PORT HEADS WITH RECTANGLE PORT GASKET BELOW polishing and smoothing these combustion chambers,surfaces, removing the sharp ridges etc, has shown noticeable benefits in...

garage.grumpysperformance.com

 

[Bextreme04]

I would pull the heads and see what it looks like. If its just a few dings and a dial indicator doesn't show a bent rod, I would likely just get new heads and a nice towing/rv cam and put it all back together. The L29 heads are a great option, but be aware they don't have a heat crossover, so they will be harder to start in extreme cold weather.

 

[animal]

 

[scrap--metal]

My vote if you want easiest/quickest, swap a crate in from a reputable company and roll on. Machine work, any labor really, is expensive in the Puget Sound area and who knows what the end result will be. Plus, what is your time worth per hour? It may be cheaper to buy vs. build it, especially wrangling three kids I would imagine.

Welcome! And I agree with Dave, a crate engine will be the simplest solution.

You'll probably be able to save yourself several hundred dollars rebuilding the existing engine yourself, but if something goes awry or if you find a less than reputable machine shop, you'll quickly be out any potential savings. Reputable machine work is expensive, and the guys who know what they're doing have waiting lists.

If you need it running to carry your camper this winter (or maybe it just hold the camper for winter storage?), the crate engine route will be quicker too.

 

[Terry Wilkerson]

Welcome from KC

 

[Turbo4whl]

..... Towed to mechanic and he reports that a scope of cylinder 1 shows a dinged piston and bent valve. He believes the timing got off bad enough that pistons and cylinders collided. I didn't know that was possible but he says 454's are interference engines. A second opinion mechanic doesn't think that is what happened, he thinks it more likely that a valve got stuck on build up and the slammed into the cylinder.

Depending on the year and what pistons are installed the 454 is not a free wheeling engine. Yes the pistons will hit some intake valves if the cam stops spinning. The bottom end may be just fine. Yes cam and refresh the heads as stated.

Question, have you pulled a valve cover and cranked the engine over to see if valves are moving? Even easier, pull the distributor cap and see if the rotor spins when turning over the engine?

Early 454's had cam drive gears with nylon teeth to drive the chain. Common for an old gear to loose a tooth or two, then the chain slips and wipes all the teeth of the gear.

@Keith Seymore What years had a factory quiet gear on the cam. I know my 1971 did.

 

[PeteJr]

Welcome from NW Mississippi.

 

[Hoss]

Welcome.
I'd search out a reputable machine shop in your area, and have your engine rebuilt (long block), using quality parts.
As for doing the work yourself, sounds like you're up for it, so go for it.
Good luck.

I was leaning this direction but it seems that there are only two machine shops in my county and only one comes recommended. It also could be a 2 month wait once I get the block to them. I do plan to pay the $800 core to keep the original engine and rebuild it when I have more time and knowledge and money for tools and parts. Thank you.

 

[Hoss]

Howdy neighbor! My vote if you want easiest/quickest, swap a crate in from a reputable company and roll on. Machine work, any labor really, is expensive in the Puget Sound area and who knows what the end result will be. Plus, what is your time worth per hour? It may be cheaper to buy vs. build it, especially wrangling three kids I would imagine.

I think this is what I've settled on. We are also in the middle of a move so time is limited or I would have already started pulling parts. The S&J long block is built in Spokane with American parts and is only $2,250 with the 7 year warranty. The mechanic I talked to on the phone recommended upgrading to a Melling MTC-6 cam for my purposes. He said he wouldn't change any other parts on the longblock.