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1G Machinist questions

dwb

Proven Member
168
64
Sep 9, 2021
Broomfield, Colorado
Maybe I should be posting this in the noob forum because I'm definitely a noob when it comes to engine rebuild. But hopefully there will be some good info here anyway. Maybe this stuff has already been discussed but it's hard to search this site.

I'm prepping my 6bolt turbo head, block, and crank to take to the machine shop after a timing belt mishap and 270k miles on the bottom end. I'm not looking for much more than an OEM rebuild and I will do all the assembly myself. The head I will be using was pulled from this same running engine at 220k, so no known bent valves or warpage. I do not believe anything has ever been machined before. So far I've found no major damage. The crank has a little scoring that can likely be polished. Bores don't have any deep scoring but will need to be machined. I haven't yet removed the valve springs so I'm unsure the condition of the valve seats or the valves.

So the block and crank are basically ready to go. Before I take them in, what, if anything, should I do to them? Should I send the block with the main bolts and caps? What about balance shaft bearings, freeze plugs, oil plugs, dowel pins, and studs - should I remove any of those beforehand? What should I be asking my machinist to be doing specifically and should I bring a spec sheet of what I expect? Again, being a noob I'm not sure what to ask or provide.

As far as the head, I'll definitely have it decked. At what point do I need to have the seats machined? Seems that might get expensive. If I plan to reuse the valves, do those have to be machined or can they just be cleaned and lapped?

All this is uncharted territory for me but I'm really excited to get the opportunity (aka wife said OK). Thanks for everyone's input so far!

Probably more questions to come...
 

1990TSIAWDTALON

Moderator
9,146
4,975
Nov 14, 2013
Independence, Kansas
Well nothing about a 4g rebuild is cheap. Do it right, do it once, and be proud of yourself. It can be done.
Let the machine shop take care of the freeze plugs/oil galley plugs and all the little stuff. Thats what your paying them for. Take a picture before and after to make sure you got all of your dowels and what not back. Polish the crank if you measure it within tolerances. Make sure you CLEAN EVERYTHING....the machine shop isn't responsible for that. I will stress the cleanliness next to godliness thing here.
Same for the head. Have it done so it is good to go. Resurface if necessary. Do Not Skimp on that. Same with the deck of the block.
This can get much more in depth so if you have some specific questions, I'm sure someone here can help out.
Marty
 

DSMPT

DSM Wiseman
2,002
1,553
Jun 12, 2014
Japan / Mexico, Arizona
So the block and crank are basically ready to go. Before I take them in, what, if anything, should I do to them?
If you would fully overhaul, I recommend to check main journals and get them line-honed if necessary, even you are planning to use the stock main bolts. And also you should check the straightness of crank.
As far as the head, I'll definitely have it decked.
I recommend to do it on the block side, too.
If I plan to reuse the valves, do those have to be machined or can they just be cleaned and lapped?
You could probably reuse the valves if they were perfectly straight. But in your case I would replace them. I remember that you made them contacted to pistons. Even if they look straight, they are possibly bent already and will never seal well.
And with new or another set of valves, lapping first and check if the valves would seal well or not by vacuum or liquid test. If you see no leak it's probably fine. In case if it still leaks after lapping, ask a machine shop to cut the valve seats. That would probably be cheaper than replacing the seats. In case if the valve seats are worn/damaged and don't have margin to cut anymore, then you have to replace the seats.
Don't forget to inspect the valve guides condition, too.
 

dwb

Proven Member
168
64
Sep 9, 2021
Broomfield, Colorado
All good stuff. Thank you.
You could probably reuse the valves if they were perfectly straight. But in your case I would replace them. I remember that you made them contacted to pistons. Even if they look straight, they are possibly bent
You are correct, I do have a head with bent valves. Not going to try to salvage those. This is a different head with higher mileage I'm working with.

On that note, are there any parts that should not be swapped from one head to another, assuming identical heads? Mr bentvalve has a lot fewer miles with 3g lifters and I'd like to swap the better parts over.

Make sure you CLEAN EVERYTHING....the machine shop isn't responsible for that. I will stress the cleanliness next to godliness thing here.
Before machining? I've got it decently clean now. Much more cleaning will be done before assembly.
 

DSMPT

DSM Wiseman
2,002
1,553
Jun 12, 2014
Japan / Mexico, Arizona
You are correct, I do have a head with bent valves. Not going to try to salvage those. This is a different head with higher mileage I'm working with.
Oh I see.

On that note, are there any parts that should not be swapped from one head to another, assuming identical heads? Mr bentvalve has a lot fewer miles with 3g lifters and I'd like to swap the better parts over.
If you reuse some parts, you can swap the lifters, rocker arms, springs, retainers, keepers, spring seats. But the cam caps shouldn't be swapped.
 

1990TSIAWDTALON

Moderator
9,146
4,975
Nov 14, 2013
Independence, Kansas
Before machining? I've got it decently clean now. Much more cleaning will be done before assembly.
After the machine work is done. I have found "swirleys" of aluminum in the head after I had it machined. I only noticed because I put the head on a pc of plywood and when I picked it up, there was quite a bit of debris. I took the compressed air hose to it and the stuff just kept coming out. Same with the crankshaft dead end throws. Clean those until you don't get anything out of them. You would be surprised what is hiding in there. I clean that no matter what. I usually take my blocks to the car wash and give them a thorough soapy water cleaning, using gun cleaning brushes, and then air dry with compressed air and wipe the cylinders with AFT. Spray the rest of the block with a anti-rust spray (I use WD40). Then wipe it all down. That will keep surface rust from forming and it will form fast, so I do that immediately after the washing of the block. I have a lot of tips, you just need to ask to be sure, don't be shy.
Marty

You can get an idea of things from these short videos from my channel. I build all kinds of motors. Sorry I didn't do one on the crankshaft cleaning, it would have been a long video.
HERE
HERE
HERE
HERE
HERE
and HERE for kicks.
 

dwb

Proven Member
168
64
Sep 9, 2021
Broomfield, Colorado
After the machine work is done. I have found "swirleys" of aluminum in the head after I had it machined. I only noticed because I put the head on a pc of plywood and when I picked it up, there was quite a bit of debris. I took the compressed air hose to it and the stuff just kept coming out. Same with the crankshaft dead end throws. Clean those until you don't get anything out of them. You would be surprised what is hiding in there. I clean that no matter what. I usually take my blocks to the car wash and give them a thorough soapy water cleaning, using gun cleaning brushes, and then air dry with compressed air and wipe the cylinders with AFT. Spray the rest of the block with a anti-rust spray (I use WD40). Then wipe it all down. That will keep surface rust from forming and it will form fast, so I do that immediately after the washing of the block. I have a lot of tips, you just need to ask to be sure, don't be shy.
Marty
I am a bit concerned about the crankshaft dead end throws after reading up on it. Seems that debris sometimes comes loose during break-in. I don't think I have a chance of pulling the balls so I'm going to do my best with a solvent. Is brake cleaner the preferred solvent here? I sprayed some carb cleaner in there last night and didn't notice any debris come out. I had thought about plugging the oil hole on one side and filling it with solvent from the other and let it soak. Would it be worth my effort to find a wire brush that fits in there?

I went out and bought a pressure washer that did a nice job on the exterior of the long block. I was curious if water was a no-no on the internals, but I figured as long as I blow dry and oil it should be good. You just confirmed my thought. The catch-22 with the pressure washer is now I've got a honey-do-list around the house.
 

1990TSIAWDTALON

Moderator
9,146
4,975
Nov 14, 2013
Independence, Kansas
I can't pull the balls on my cranks either but I use Brake Parts Cleaner and I bend the straw so it will go down into the throw. I have used as much as 7 cans on a crank and and little as 2 cans, but they all had crap in those throws, as you probably saw on the white sheet I had laying down in that thread. I always used compressed air to blow them out as I go.
 

1990TSIAWDTALON

Moderator
9,146
4,975
Nov 14, 2013
Independence, Kansas
I haven't watched the video but I CAN tell you a car wash won't get all of the crap out of the crankshaft. :)
Another tip - put a raincoat on backwards when cleaning the stuff with a pressure washer or the carwash. A face shield is also a handy thing to wear. You have to do it yourself to really know. ROFL
Marty
 

1990TSIAWDTALON

Moderator
9,146
4,975
Nov 14, 2013
Independence, Kansas
Machine shop stuff. Out of all of my builds, I have not ever line -honed them. It is a good thing to do, but the shops around my area don't have the equipment. If a motor was running before a tear down, I tend to think the crank journals are still good and the block/caps are straight still. If you are throwing a random bunch of parts together to build a motor, then most certainly, a line-hone would be prudent.
 

dwb

Proven Member
168
64
Sep 9, 2021
Broomfield, Colorado
If a motor was running before a tear down, I tend to think the crank journals are still good and the block/caps are straight still. If you are throwing a random bunch of parts together to build a motor, then most certainly, a line-hone would be prudent.
Yep, was running before and I'm reusing as much as I safely can. I have no reason to believe anything is out of whack. Thanks!

Now more questions:
Do I buy the main/rod bearings and pistons/rings before or after machining?
Also looking for information on head, main, and rod bolts or studs. Are any of the OEM bolts reusable for an ~OEM build? When would you run something like ARP studs over OEM bolts?
 

CrackedDSM

Proven Member
1,896
560
Dec 17, 2009
Pensacola, Florida
Yep, was running before and I'm reusing as much as I safely can. I have no reason to believe anything is out of whack. Thanks!

Now more questions:
Do I buy the main/rod bearings and pistons/rings before or after machining?
Also looking for information on head, main, and rod bolts or studs. Are any of the OEM bolts reusable for an ~OEM build? When would you run something like ARP studs over OEM bolts?

Typically buy the bearings afterwords. For the pistons you tend to get the block checked and see if the bores are fine or if they need to be bored over/out. When that happens you buy the oversized pistons and rings you need and if they’re aftermarket/forged pistons bring them to the machinist so they can set the proper tolerances for pistons to wall clearance and etc.


For 6 bolts the stock head bolts are reuseable and stronger than basic arps(arps have better clamping load and etc, but honestly stock six bolt head bolts are fine for basic builds, 7 bolt is a different story). I would however buy new fasteners because it’s just great piece of mind.
 

dwb

Proven Member
168
64
Sep 9, 2021
Broomfield, Colorado
I'll be taking my head/block/crank to the shop tomorrow. HiPro Engines weren't taking any additional jobs for another month so I looked around and found another fairly local shop to Denver that seem to specialize in Japanese and American platforms. They specifically list the 4g63 DSM/EVO on their website and they said they can do the work. It's Madcap Racing Engines and fingers crossed everything works out. Their prices are higher than some other generic shops I called around to but I want it done right the first time. Looks like $1000 - $1500 depending on what I have done.
 
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