420A Help with my 420a non turbo block. Super newb here!

[Harleyoi]

A little nudge in the right direction would be awesome for this plumber about to dive into pulling an engine, with my 15 year old son for his first car! I purchased a cylinder head for my 420a non turbo. Thinking it would be pretty easy to find a machine shop to take care of the block for me. Ha, joke is on me. Not having luck finding a machine shop that will do everything and build the short block for me without a six month wait, and I only found 1 shop, and he really didn't seem like he was very interested. However I'f I strip the block I have found a couple shops that can polish, and "hone" (hopefully I sound like I know what I'm talking about) the block in about a month for me.

My question is. How difficult is it to remove the crankshaft, pistons, oil pump, and anything else that I'm missing? And then how difficult is it to put it all back together? I do have the haynes. And like I said the cylinder head is a beauty, and ready to go. Just focused on the block now.

I have everything ready to pull it this Saturday, here in Phoenix. Any help, tips, or advice would be super rad. Thanks a lot!

 

[BLACK'98DSM]

You're in luck because the 420a short block is fairly simple and easy to play with. No balance shafts or complicated rotating assembly. You can navigate through 2gnt.com and find detailed 420a rebuild guides. Or you can use service manuals. The manuals will be more technically correct but online guides will have the experienced input.

Tearing the engine apart is super easy. I didn't even label my hardware the first time I rebuilt one, because it's nearly self explanatory where each item fits. There's nothing inside the engine besides an oil pickup tube, crankshaft, rods and pistons. Not even oil squirters or a windage tray. All accessories are mounted on the exterior side of the block. I will recommend separating the water pump bolts as they are quite specific but can be confused with other hardware of the same thread pitch.

Feel free to send me a private message if you would like assistance with any part of the process. Perhaps I can share my experience with this engine. They are out dated and forgotten engines but I still play with them, I guess I'm not right in the head.

 

[97egl]

If you are not having the block bored for larger pistons I would suggest just honing it yourself. It very easy and then you don't have to wait for the machine shop.

As Black98 said above they are very simple engines. To tear it down the only specialty tool you should need would be a puller for the crankshaft pulley. The other thing i would mention is that the block has a bedplate which will have to be removed to take the crank out. When you put it back together you'll want to use the correct sealer. I've seen people use rtv and others use nothing at all and end up with a leak. The sealant you need to use is like loctite. I can't remember the part number for it off the top of my head hopefully its in the manual you have.

 

[Harleyoi]

You're in luck because the 420a short block is fairly simple and easy to play with. No balance shafts or complicated rotating assembly. You can navigate through 2gnt.com and find detailed 420a rebuild guides. Or you can use service manuals. The manuals will be more technically correct but online guides will have the experienced input.

Tearing the engine apart is super easy. I didn't even label my hardware the first time I rebuilt one, because it's nearly self explanatory where each item fits. There's nothing inside the engine besides an oil pickup tube, crankshaft, rods and pistons. Not even oil squirters or a windage tray. All accessories are mounted on the exterior side of the block. I will recommend separating the water pump bolts as they are quite specific but can be confused with other hardware of the same thread pitch.

Feel free to send me a private message if you would like assistance with any part of the process. Perhaps I can share my experience with this engine. They are out dated and forgotten engines but I still play with them, I guess I'm not right in the head.

☝☝I feel like I'm in good company, I question my sanity also. Thank you for the solid information there, I feel a little more at ease now. It doesn't sound to horriblely difficult. I am exited to give it a go, and appreciate the option to shoot you a message. You may just hear from me. Thank you for the advice.

If you are not having the block bored for larger pistons I would suggest just honing it yourself. It very easy and then you don't have to wait for the machine shop.

As Black98 said above they are very simple engines. To tear it down the only specialty tool you should need would be a puller for the crankshaft pulley. The other thing i would mention is that the block has a bedplate which will have to be removed to take the crank out. When you put it back together you'll want to use the correct sealer. I've seen people use rtv and others use nothing at all and end up with a leak. The sealant you need to use is like loctite. I can't remember the part number for it off the top of my head hopefully its in the manual you have.

It definitely is a manual, it was soo much fun teaching my son how to drive it. He is doing awesome, now he is excited to pull the engine this weekend. Super cool.

Thank you for your response, so basically all they do at the machine shop for blocks is hone, and polish them? I'm definitely going to look into honing them myself.

And definitely noted about the sealant, I will look for the recommended stuff. Good call on the crankshaft pully, that will definitely be my problem now haha. I appreciate man.

 

[97egl]

It definitely is a manual, it was soo much fun teaching my son how to drive it. He is doing awesome, now he is excited to pull the engine this weekend. Super cool.

Thank you for your response, so basically all they do at the machine shop for blocks is hone, and polish them? I'm definitely going to look into honing them myself.

And definitely noted about the sealant, I will look for the recommended stuff. Good call on the crankshaft pully, that will definitely be my problem now haha. I appreciate man.

The machine shop can do much more than just hone and polish but it sounded like you were just looking at having it honed.

What is your reasoning for taking the short block apart?

 

[jesse12345]

I dont know what it is about these engines that machine shops don't want to touch. I to had the same issues with finding a machine shop to even just check it out. Nobody wanted to even look at it for me so I took it all into my own hands. I dove right in and everyone is right they are very easy to tackle.

 

[BLACK'98DSM]

That is strange to me. I'm not sure why shops would turn away such simple work. I've never looked for someone else to rebuild one, but even the machine shop nearest my home will do the machine work.

Something else I would do with the block is have it resurfaced. You typically don't hear about this with iron blocks and most people will just run a scotch brite pad across it. But you want that surface to be almost perfect if you're using an MLS headgasket. You could skip on this and risk using a composite gasket to compensate for surface imperfections. But having a block resurfaced usually only costs me $20-$30. Worth just spending the money and having it done right.

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[Harleyoi]

I dont know what it is about these engines that machine shops don't want to touch. I to had the same issues with finding a machine shop to even just check it out. Nobody wanted to even look at it for me so I took it all into my own hands. I dove right in and everyone is right they are very easy to tackle.

Thank you for your reply, definitely helps this dude a lot! I'm actually getting excited about it!

 

[Harleyoi]

That is strange to me. I'm not sure why shops would turn away such simple work. I've never looked for someone else to rebuild one, but even the machine shop nearest my home will do the machine work.

Something else I would do with the block is have it resurfaced. You typically don't hear about this with iron blocks and most people will just run a scotch brite pad across it. But you want that surface to be almost perfect if you're using an MLS headgasket. You could skip on this and risk using a composite gasket to compensate for surface imperfections. But having a block resurfaced usually only costs me $20-$30. Worth just spending the money and having it done right.

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Definitely noted, thank you again!

 

[chrysler kid]

You can get the full factory service manuals online at Www.charm.li.

Its a site dedicated to free factory service manuals from 1983 to 2013

 

[Harleyoi]

You can get the full factory service manuals online at Www.charm.li.

Its a site dedicated to free factory service manuals from 1983 to 2013

What an awesome link, thanks for sharing!