lowenbrau
SILVER Star
Get the block as hot as you can before you start and then blast the sleeve with a CO2 fire extinguisher. I've been told it'll fall right out.
pre cup destruction
- Thread starter cruisedeisel
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cruisedeisel
Toyota's for life
- Thread starter
- #42
REALLY??? it does make sence. but does it make dollars???
IMOP the precup is a 150-200,000km maintenace item. Every 100,000km change them out if you are that parenoid. Afterall they are not that hard to replace, basically a Saturdays work and less than $500. Incorporate nozzle O/H while you are at it.
We spend more on suspension upgrades and some people spend(waste) plenty more on unnecessary upgrades cause they look cool!
Heating the block and chilling the sleeve will make removal /installation ALOT easier. I regularly heat aircraft wheel assemblies and chill bearing races and they virtually fall together versus trying to pound the race into the wheel half when they are the same temperature.
Daryl
We spend more on suspension upgrades and some people spend(waste) plenty more on unnecessary upgrades cause they look cool!
Heating the block and chilling the sleeve will make removal /installation ALOT easier. I regularly heat aircraft wheel assemblies and chill bearing races and they virtually fall together versus trying to pound the race into the wheel half when they are the same temperature.
Daryl
Yes, this is a good idea. The grocery stores near me sell dry ice in a special cooler now - would work even better than the fire extinguisher (less mess). You should be able to find a local supplier and just fill the liner with dry ice with your puller plate blocking the bottom.
Or even better: LN2 if you have a local university.
EDIT: For comparison, here are the minimum temperatures you might expect:
Ice water: 0C
Ice/salt: -20C
R-134a bath: -26C
Dry ice: -78C
Dry ice/acetone: -100C
LN2: -196C
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I didnt see it mentioned here but the problem with the DIY liner replacement on a 3B is that the available liners are rough liners. Which means they would possibly need to be bored and at minimum they need to be honed.
In the scope of costs for a proper rebuild - why not just have a machinist do it?
In the scope of costs for a proper rebuild - why not just have a machinist do it?
lowenbrau
SILVER Star
You can buy liners semifinished or fully (pre) finished. I don't know why anyone would bother with the semifinished ones but there is probably a good reason.
I had the choice and I bought unfinished liners (for my pile of spares) on the basis that
- the liners could distort when being pressed into the block, and
- a good machinist could do a much better job of matching the bore of each particular pressed-in liner to the matching individually-numbered new-pistons that I would be supplying them with.
PS. But I admit the big problem these days would be finding the skilled machinist because all trades/industries seem to have been dumbed-down so much (as far as training of new people is concerned)
lowenbrau
SILVER Star
I had the choice and I bought unfinished liners (for my pile of spares) on the basis that
- the liners could distort when being pressed into the block, and
- a good machinist could do a much better job of matching the bore of each particular pressed-in liner to the matching individually-numbered new-pistons that I would be supplying them with.
PS. But I admit the big problem these days would be finding the skilled machinist because all trades/industries seem to have been dumbed-down so much (as far as training of new people is concerned)
That makes sense but why not just install finished liners and only machine them if they actually do measure distorted? Are the semi finished ones a lot cheaper?
For reference, does anyone know the spec for the outside diameter of the liners? Is it an interference fit? I think its in the FSM but don't have my copy.
Because then they end up too big and standard pistons won't fit.
To my knowledge, you simply can't properly re-machine (or rework in any other way) a finished liner back to "true status" if it has been distorted during fitment Lowenbrau. (Assuming you want a "professional" job here.)
And I can't remember price as being a significant factor in the choice between "finished" and "unfinished" liners at Engine Australia (where I bought my liners).
But all this discussion doesn't mean I'm 100% sure I've chosen the best path (by buying unfinished liners). I'm always keen to do as much work as I can myself and am always very reluctant to put any part of my cruiser in someone else's hands. So I sometimes ponder along these lines ...... "Surely the head plays a significant part in holding my liners in position. And surely I could 'ease the fit' of my new liners somewhat by removing a little metal from their OD to achieve less of an interference fit (assuming the existing fit requires a very powerful press)." (BTW - I have a lathe and large external/internal micrometers etc.) But then to go down this track I'd have to be confident the finished liners and new pistons would "fit within spec". And being a really suspicious bastard ... I wasn't confident of this. ...... I think I know the country-of-origin for the Engine-Australia parts I bought but then these days that's mostly irrelevant in determining the quality. However I have no idea of the extent of the manufacturing standards in this source factory! (All I can say is that the parts I eventually bought LOOK fine.) So if the piston-liner fit is really OK for finished-liners... maybe I should have chosen the "finished" route?
Oh. And my thinking is probably also clouded by being an old bastard too. I recall engine reconditioners numbering pistons and then individually matching each of these pistons to its appropriate bore during machining work. Perhaps nowadays the equipment is so precise that such individual steps are obsolete?
It is definitely an interference fit for Toyota to say a 5000kg press is required Drew. But I don't see any figures in the FSM for it (or even for the liner OD). However, I know there are charts detailing interference-fits and it would be easy enough to refer to them and use outside/inside micrometer gear.
PS. I suspect the tight fit was done to allow the liners to be machined-in-place for oversized pistons without them coming loose..... because my FSM says you can do this.
The interference fit is for conduction of heat. The liners take a lot of heat through combustion and the piston rings, they need to contact the block well to dissipate that heat.
My experience with liners is removal is the big evil. Due to corrosion and the fact they've been in place for many years means they're quite friendly. I don't recall how much force the press we used on a perkins a few months back was, but the liners unseated with a lot of banging and popping. They were rusted in.
On reinstall the interference fit is minimised or even taken down to a size-for-size fit by freezing the liners. So much so they can often be tapped in with a sledge hammer and block of wood.
My experience with liners is removal is the big evil. Due to corrosion and the fact they've been in place for many years means they're quite friendly. I don't recall how much force the press we used on a perkins a few months back was, but the liners unseated with a lot of banging and popping. They were rusted in.
On reinstall the interference fit is minimised or even taken down to a size-for-size fit by freezing the liners. So much so they can often be tapped in with a sledge hammer and block of wood.
Bringing a not-to-terribly-old post back.
Is it possible to rid yourself of the worry about pre-cups by acquiring a 13bt head? From my understanding, with direct injection there is no pre-cup to fall in.
If that is true, what other mods would it take to fit up a 13bt head?
Where could one source a head in N. America?
Is it possible to rid yourself of the worry about pre-cups by acquiring a 13bt head? From my understanding, with direct injection there is no pre-cup to fall in.
If that is true, what other mods would it take to fit up a 13bt head?
Where could one source a head in N. America?
This seems to be a common misconception. The head alone is not really interchangeable.
In order to use the head you would need the following parts and possibly others.
Head
injectors
injector lines
connecting rods
13B pistons
injection pump or potentially serious mods to your existing pump
The main issue is the fuel system change (direct injected 13B vs indirect 3B) . The combustion chamber moves to the piston instead of the pre-cup.
In order to use the head you would need the following parts and possibly others.
Head
injectors
injector lines
connecting rods
13B pistons
injection pump or potentially serious mods to your existing pump
The main issue is the fuel system change (direct injected 13B vs indirect 3B) . The combustion chamber moves to the piston instead of the pre-cup.
Are you thinking of the 13btii rotary injection pump? Or is there a significant difference between the inline pumps found on the 13bt and the 3b?
Basically same question as above.
Since I have the engine out and am doing a transplant into an FJ chassis, it wouldn't be too big of a deal to swap the pistons and rods. Already have the pan off for a oil drain bung from the turbo (one of Keith's kits). The hard part would be sourcing the stuff.
Am I worrying too much about these cups to go to these lengths? I really don't want to smash my engine after it's (conservatively) boosted.
Once you go Di, you'll never go back. If you're at the rebuild stage already, do it.
It has been done for Isuzu 4BD2 to 4BD1, shouldn't be too much different for 3B to 13B.
lowenbrau
SILVER Star
It is a slippery slope. If you are changing pistons anyway, why not swap the crank and make it a 14B? Then you might even be able to overbore it and turn it into a 15B but I'm not sure about that.
I've used that rationale before, and now I'm married.
Tell me more about the 14b crank swap...
