1979 2F Rebuild Questions (1 Viewer)

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Joined
Feb 21, 2017
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Location
Olympia
I’ve got my 1979 2F completely torn down (minus the timing plate) and looking for the collective wisdom of Mud to help me determine what I ought to be replacing and what is cleanable/fixable. Really everything from the block to pistons and rods, lifters, gears, crank and cam, etc. etc. I’m an absolute beginner with engine work, but since I’ve got it completely apart I figure the ONLY thing to do is invest the time and money in replacing everything I can that makes sense to replace.
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Here are the pistons and rods. I have domed pistons, which I gather will require some investment to procure oversized if I require cylinder boring. Which leads me to…..
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The cylinders are all varying degrees of this condition. Some seem better, but this is the worst. Any chance this can be honed, or am I looking at having to get them bored? Below you can see where I’ve wiped away some of the “crust”. Seems to come off easily?
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Thanks for the help. Ive owned these 40’s for 5 years now and only recently have been able to start tearing into them. I’ve learned so much from the forum and I’m Looking forward to hearing what you all think.
 
Step 0 to me is cleaning and checking the block and cylinder bores, as well as the crank. The findings there will drive a lot of the rest.

If it has any sort of mileage, I'd suspect it may need to be bored out a size or two...and replacement dometop pistons may be hard to find. I snagged my set in 2020, and it was some of the last it seemed.

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*IF* it needs to be bored out, you'd need oversize pistons...and it may be hard to find anything but flattops. *IF* that's the case, you'd need to track down the newer cylinder head to use with that style of piston.

Past that, likely good to refresh the bearings as they're cheap, and the cam/lifters would depend on wear (but also fairly reasonable).
 
Main bearings gave me havoc trying to get the right ones (tail end of shipping woes) and the thrust side still wasn't right. (Like a toothbrush cap on too tight and nothing comes out when squeezed.)

I used ITM Engine Comp pistons - the RY6215 (purchased spring 2022) - they are dome

A good cleaning like @zerotreedelta mentioned and look for things... I missed the harmonic balancer was speedi sleeved by the PO - even when putting it on I didn't notice - details... issues with it and had to get a new balancer - that was quick - point it go slow, inventory.
 
Step 0 to me is cleaning and checking the block and cylinder bores, as well as the crank. The findings there will drive a lot of the rest.

If it has any sort of mileage, I'd suspect it may need to be bored out a size or two...and replacement dometop pistons may be hard to find. I snagged my set in 2020, and it was some of the last it seemed.

View attachment 3219057

*IF* it needs to be bored out, you'd need oversize pistons...and it may be hard to find anything but flattops. *IF* that's the case, you'd need to track down the newer cylinder head to use with that style of piston.

Past that, likely good to refresh the bearings as they're cheap, and the cam/lifters would depend on wear (but also fairly reasonable).
Seems that is a good plan. The pistons look cruddy--but they always look cruddy--most looks to be just gunk that a good soak in carb dip will fix--the Rings are what will make or break--(if) the cylinders are in spec.
Most of the crud in there is well below where the pistons move anyway--not important for compression--but important to clean so it doesn't fall down into the oil pan--
The top blemishes may be able to be polished out without too much honing--then the bores need to be checked to make sure they are in spec or not--if you need a set of bore gauges, I have them, and could loan to you if needed--
The rod bearings look quite clean--but, those also should be checked for proper size and clearance--if they are very far out-check the crank as well while you are in there-Zerotreedelta has good advice---
if the rod brgs are out--the cranks prob are as well--cheap insurance to replace--
Check with Toyota South Atlanta--they are able to get OEM when others can't--luck!
 
Seems that is a good plan. The pistons look cruddy--but they always look cruddy--most looks to be just gunk that a good soak in carb dip will fix--the Rings are what will make or break--(if) the cylinders are in spec.
Most of the crud in there is well below where the pistons move anyway--not important for compression--but important to clean so it doesn't fall down into the oil pan--
The top blemishes may be able to be polished out without too much honing--then the bores need to be checked to make sure they are in spec or not--if you need a set of bore gauges, I have them, and could loan to you if needed--
The rod bearings look quite clean--but, those also should be checked for proper size and clearance--if they are very far out-check the crank as well while you are in there-Zerotreedelta has good advice---
if the rod brgs are out--the cranks prob are as well--cheap insurance to replace--
Check with Toyota South Atlanta--they are able to get OEM when others can't--luck!
Here's the link to Toyota So. Atlanta Parts--


they still have:
Ring set-$470
Ring set -.50 Ovr size $572
Ring set 1.00 ovr size - $572
Rod brg set - $121
new crank - $718--
Plus a bunch of bolts, rod nuts, the crank seals, etc.---unfortunately-no more domed pistons--
You gotta look around on Toyota's parts site---for example- they list the overhaul gasket set as NLA, but if you look at the head diagram, you can still get the oem head gasket, and exh manifold gaskets separately--same for the timing cover gasket, or, what is really important is the oil pan oem gasket(it comes as one piece--not four)
Search the site--be aware that one diagram may say the part is NLA but a diff diagram may list the part as available--order that one and it will come to you in a matter of a few days.--
 
My guess is that when the engine is spinning on its own, that the rust in the cylinder walls will contribute to some burnt oil. Honing will help you achieve proper oiling, but, not removal of rust pits.

I'm quite conservative in approach, change as little as needed to get to FSM specs, and use as much/many original Toyota parts as possible, just my personal feelings, not very experienced.
 
Past that, likely good to refresh the bearings as they're cheap, and the cam/lifters would depend on wear (but also fairly reasonable).
Delta Cam is local to me and I’ve seen them
mentioned as a good option for cam work. I’ve got quite a bit of rust on the cam, and the lifters have some discoloration but seem like they might be able to be cleaned up. I’ll definitely get the block cleaned up. What specifically should I be checking for on the block and crank?
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I missed the harmonic balancer was speedi sleeved by the PO - even when putting it on I didn't notice - details... issues with it and had to get a new balancer - that was quick - point it go slow, inventory.
speaking of balancers, it seems like a rather spendy part. Is there a good way to tell whether the one I have is still usable? I thought I read that the rubber in them can break down and cause headaches down the road.
6AE5BAB3-4691-4C6E-89D1-2C5B48DB7D27.jpeg

Seems that is a good plan. The pistons look cruddy--but they always look cruddy--most looks to be just gunk that a good soak in carb dip will fix--the Rings are what will make or break--(if) the cylinders are in spec.
Most of the crud in there is well below where the pistons move anyway--not important for compression--but important to clean so it doesn't fall down into the oil pan--
The top blemishes may be able to be polished out without too much honing--then the bores need to be checked to make sure they are in spec or not--if you need a set of bore gauges, I have them, and could loan to you if needed--
The rod bearings look quite clean--but, those also should be checked for proper size and clearance--if they are very far out-check the crank as well while you are in there-Zerotreedelta has good advice---
if the rod brgs are out--the cranks prob are as well--cheap insurance to replace--
Check with Toyota South Atlanta--they are able to get OEM when others can't--luck!
Assuming cylinders are still in spec and don’t require boring and oversized pistons, are rings something that ought to be replaced regardless, since I have the motor opened up? I want to start with as close to a “0” mile engine as I can after I invest the time/money in rebuilding. Thanks for the lead on Toyota South Atlanta. Lots of great parts I already know I need.
My guess is that when the engine is spinning on its own, that the rust in the cylinder walls will contribute to some burnt oil. Honing will help you achieve proper oiling, but, not removal of rust pits.

I'm quite conservative in approach, change as little as needed to get to FSM specs, and use as much/many original Toyota parts as possible, just my personal feelings, not very experienced.
Definitely trying to use original parts where I can find them!

Thanks everyone for your help. You’re all helping this seem significantly less daunting then when I started out.
 
Backing up just a smidge, an even better step 0 is snagging a copy of the 2F factory manual - it's actually quite good/useful, and worth a read through section 3. It walks through disassembly and inspection, including how to measure and expected tolerances. Most are rather straightforward, but do need a dial indicator, bore gauge, and some micrometers.

They're fairly straightforward motors - I didn't have the equipment for boring and surfacing, so I did need to take the block and head in to an industrial engine shop for machining. They also polished up the crank and checked it for runout (harder to do at home) and pressed in new cam bearings (requires specific tooling).

Depending on what you know on the motor, it's also worth checking to see if it's been bored out before (the cylinder tops would typically be stamped with the overbore) or if the crank has been machined (any oversize bearings would also be stamped). Any idea on mileage on the engine/history?


 
Got it all apart and dropped off with my machinist. Waiting to hear how much boring he needs to do in the cylinders before I start hunting for appropriately oversized pistons. I know the oversized domed pistons are extremely rare at this point and may end up having to buy the custom Wisecos.

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