New member, blown motor!

[Hoss]

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

Thanks for all this info. I'm likely ordering the S&J longblock but keeping my engine to rebuild maybe next year. I will look into these heads. Maybe the crate build will be mostly stock and the original motor rebuild can be more HP where I can get it. I had already ordered RPM Air-Gap intake and AVS-2 800cfm carb before the mishap. Now I'm researching new pumps and other peripherals, hopefully made in USA.

 

[Hoss]

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.

Thanks for these threads. When I have more time after moving and vacation in September I will pull the covers and check it out and let you know what I find.

 

[Hoss]

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.

Agreed. 1 good shop in my area and I can't imagine I can build a machined longblock with new parts for less than the S&J option. I also can't afford to wait for that right now. Thanks.

 

[Hoss]

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.

I plan to diagnose in September. Summit has only steel timing sprockets for Mark IV 454 but I guess that doesn't mean they didn't come with nylon in 1985. A second opinion mechanic told me he thinks it could have just been a stuck valve from carbon buildup and it rebounded into the piston and got bent, I don't know how believable that is.

 

[Bextreme04]

Agreed. 1 good shop in my area and I can't imagine I can build a machined longblock with new parts for less than the S&J option. I also can't afford to wait for that right now. Thanks.

I had my Gen VI 454 machined at a NAPA machine shop in Woodburn, OR. They were recommended by a high end race cylinder head guy locally and they did all the machine work and ordered all the rebuild parts as well. The machine work and all the new parts came in at $2200. That didn't include the $600 it cost to have the heads completely reworked including clean/pressure check, decked, new valve guides, 3 angle valve job, clearance of the valve guide boss to allow more lift, installing new viton positive lock seals, and installation of new 454 H.O dual springs and retainers.

 

[PiutePete]

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

Something that struck me and made me think.

"Tell me what you would do If you were keeping this truck...and wanted to pass it on to your children."

If I was to leave it for my kids...I'd make sure it was done right, the first time, regardless of cost, for longevity and ease of repair. Imagine what they might say about you if you leave them with a truck they don't understand and can't work on. Buy once, cry once?

 

[Hoss]

I had my Gen VI 454 machined at a NAPA machine shop in Woodburn, OR. They were recommended by a high end race cylinder head guy locally and they did all the machine work and ordered all the rebuild parts as well. The machine work and all the new parts came in at $2200. That didn't include the $600 it cost to have the heads completely reworked including clean/pressure check, decked, new valve guides, 3 angle valve job, clearance of the valve guide boss to allow more lift, installing new viton positive lock seals, and installation of new 454 H.O dual springs and retainers.

That's great. The S&J option is right around 2,200 balanced.

 

[Hoss]

Something that struck me and made me think.

"Tell me what you would do If you were keeping this truck...and wanted to pass it on to your children."

If I was to leave it for my kids...I'd make sure it was done right, the first time, regardless of cost, for longevity and ease of repair. Imagine what they might say about you if you leave them with a truck they don't understand and can't work on. Buy once, cry once?

Absolutely. I decided to go with a crate long block from S&J since I have not yet rebuilt my own engine. Dan at S&J has been very helpful and he is helping me pick parts for the build. Does anyone have any opinion on cams ie lift and duration or flat tappet vs roller tappet for a stock 1985 block and heads for a 1 ton 454 farm truck/weekend warrior towing rig. Melling or Comp. I do prefer to buy USA made. Dan told me to return the Edelbrock RPM Air-Gap intake and just get a performer to go with the AVS2 carb. Are the any valvetrain parts that I should ask Dan to upgrade for the build?

 

[Bextreme04]

Absolutely. I decided to go with a crate long block from S&J since I have not yet rebuilt my own engine. Dan at S&J has been very helpful and he is helping me pick parts for the build. Does anyone have any opinion on cams ie lift and duration or flat tappet vs roller tappet for a stock 1985 block and heads for a 1 ton 454 farm truck/weekend warrior towing rig. Melling or Comp. I do prefer to buy USA made. Dan told me to return the Edelbrock RPM Air-Gap intake and just get a performer to go with the AVS2 carb. Are the any valvetrain parts that I should ask Dan to upgrade for the build?

Call delta camshaft in Tacoma and tell them what you have and what you want to do. I had them do a regrind on my factory roller cam. Roller is going to be the better option due to current issues with flat tappet cams and lifters, but it’s going to cost more. Mark IV block should have the provision for the cam thrust plate, but you’d need retrofit roller lifters.

 

[SirRobyn0]

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

Welcome from a little south of you!

S&J has a great reputation and it is my plan to get a motor from them when the time comes, however sometimes they can have a wait time. So I think if the truck was mine part of it would be how many miles are on the lower end. If less than 100K and runs good oil pressure I might roll the dice, if I was doing the work at least the R&R work, but like @Soundmound - Dave said shop labor, an machine shop labor are the highest in the state in the Puget sound area. It would not take to much to spend a 1K on doing heads, yourself with gaskets and machine shop labor, by then your about halfway to a motor at S&J. I see that's the path you have chosen, please let us know how you like your new motor!

 

[AuroraGirl]

I had my Gen VI 454 machined at a NAPA machine shop in Woodburn, OR. They were recommended by a high end race cylinder head guy locally and they did all the machine work and ordered all the rebuild parts as well. The machine work and all the new parts came in at $2200. That didn't include the $600 it cost to have the heads completely reworked including clean/pressure check, decked, new valve guides, 3 angle valve job, clearance of the valve guide boss to allow more lift, installing new viton positive lock seals, and installation of new 454 H.O dual springs and retainers.

my local napa machine shop just got a change in venue to a much nicer, larger area and the guys who work in it are the most anti social people ever but id guess 70% Of their work is machining agriculture engines, so lots of 4 cylinders that have cylinders bigger than some peoples heads lol

 

[Craig 85]

Welcome. I had a similar truck back in the late 90's. 1980 with an '85 front clip.

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[Gardendelite]

Welcome aboard from Maple Valley, WA. It seems to me that you are busy enough, I would go with the crate and be done with it. Kids don't stay young for long. Save the rebuild for the next time

 

[Ricko1966]

If you are buying a rebuild and paying core buy a 96-99 should already be roller. You have a hard time getting oil that flat tappet cams like.

 

[Gardendelite]

Well, that was embarrassing. This was meant for another post. That will teach me to multitask.