hi im slowly rebuilding my lj78 with a 2l te that cracked a head so i got some quotes from a couple machine shop in Christchurch new Zealand with the cheapest quote being in 4 hundreds that is to resurface head block, hone cylinders and wash everything i know it might be the best price i can get but wondering if its even necessary as the spec for block and head warp is .2 mm people say that the spec is unacceptable but idk as im new to the world of diesels. i would also need to get the pistons skimmed as its at max protrusion and thickest grade of headgasket which is also included in the price.
hi im slowly rebuilding my lj78 with a 2l te that cracked a head so i got some quotes from a couple machine shop in Christchurch new Zealand with the cheapest quote being in 4 hundreds that is to resurface head block, hone cylinders and wash everything i know it might be the best price i can get but wondering if its even necessary as the spec for block and head warp is .2 mm people say that the spec is unacceptable but idk as im new to the world of diesels. i would also need to get the pistons skimmed as its at max protrusion and thickest grade of headgasket which is also included in the price. View attachment 3857945
Are you absolutely sure there are no cracks in the head? They aren't wide open fissures, but rough hairline fractures across the valve bridge or from one valve seat to a combustion chamber.
Does the block need dressing? Was the engine run with a leaking head gasket, causing erosion of the surface? If it needs so much taking off that the thickes head gasket no longer meets the piston protrusion limit, there must be some serious warping or damage.
Are you absolutely sure there are no cracks in the head? They aren't wide open fissures, but rough hairline fractures across the valve bridge or from one valve seat to a combustion chamber.
Does the block need dressing? Was the engine run with a leaking head gasket, causing erosion of the surface? If it needs so much taking off that the thickes head gasket no longer meets the piston protrusion limit, there must be some serious warping or damage.
sorry should have clarified i parked it up because of symptoms of slight head crackage so i popped of the head and only cylinder 3 cracked in the typical spot between the valves got a used good head now for cheap with very little usage and much healthier coolant passages but other than that it ran perfect the surfaces of block and old cracked head looked pristine as the engine seems to have been rebuilt not too long ago and headgasket looks like it barely had a life lol its my first idi diesel so didn't drive it under a egt gauge oops and thats why im asking as everything looks so clean and new if i can just put it back together with a good head?
Are you absolutely sure there are no cracks in the head? They aren't wide open fissures, but rough hairline fractures across the valve bridge or from one valve seat to a combustion chamber.
Does the block need dressing? Was the engine run with a leaking head gasket, causing erosion of the surface? If it needs so much taking off that the thickes head gasket no longer meets the piston protrusion limit, there must be some serious warping or damage.
Are you absolutely sure there are no cracks in the head? They aren't wide open fissures, but rough hairline fractures across the valve bridge or from one valve seat to a combustion chamber.
Does the block need dressing? Was the engine run with a leaking head gasket, causing erosion of the surface? If it needs so much taking off that the thickes head gasket no longer meets the piston protrusion limit, there must be some serious warping or damage.
what do you mean by dressing? it seams to me that the engine has been re built more than once even tho the truck only got 220000 km on it the cross hatching is brand new but the head gasket is the thickest one of the three grades so idk, the headgasket is dry and looks so new i could reuse it which im not going to.
By dressing the block I mean a light skim to make it flat, but if it still has the milling marks from the previous work that probably isn't necessary. Make sure you use an experienced machine works that can verify the surface roughness is good enough for a multi layered steel gasket. If you can't find any warpage I would definitely not take anything more off the block. If there is still cross-hatching on the cylinder bores and the pistons are still fitted, I wouldn't touch that. If the head is flat I would not do anything to it beyond very careful inspection for cracks and checking that the valve margins and seats look good and seal a vacuum.
However, I'd be a bit suspect of a 'good used head' unless you know the story. These IDI turbos are so prone to cracking heads that it seems odd to dismantle an engine for any other reason (unless maybe it shot a rod through the block, which is also not unknown).
And I would be very, very suspicious of an engine which has clearly been neglected in the past (even one rebuild at 220k is a bad sign) and clearly either severely overheated or run for a long time with a leaking gasket (major machining of block). The fact that it almost immediately seems to have cracked another head strongly suggests there are major problems with the cooling system - coolant passages in the block, water pump, thermostat, fan clutch and radiator should all be treated as highly suspect until checked/tested.
By dressing the block I mean a light skim to make it flat, but if it still has the milling marks from the previous work that probably isn't necessary. Make sure you use an experienced machine works that can verify the surface roughness is good enough for a multi layered steel gasket. If you can't find any warpage I would definitely not take anything more off the block. If there is still cross-hatching on the cylinder bores and the pistons are still fitted, I wouldn't touch that. If the head is flat I would not do anything to it beyond very careful inspection for cracks and checking that the valve margins and seats look good and seal a vacuum.
However, I'd be a bit suspect of a 'good used head' unless you know the story. These IDI turbos are so prone to cracking heads that it seems odd to dismantle an engine for any other reason (unless maybe it shot a rod through the block, which is also not unknown).
And I would be very, very suspicious of an engine which has clearly been neglected in the past (even one rebuild at 220k is a bad sign) and clearly either severely overheated or run for a long time with a leaking gasket (major machining of block). The fact that it almost immediately seems to have cracked another head strongly suggests there are major problems with the cooling system - coolant passages in the block, water pump, thermostat, fan clutch and radiator should all be treated as highly suspect until checked/tested.
I know my dad rebuilt it not too long ago and when I inherited it I drove it and didnt have an egt gauge or even the idea of what egt is so I noticed it had slightly less power and started blowing little coolant smoke after a long highway run so I know it's all my fault, the used head thankfully the guy was gonna use it as a spare for his 3l Hilux but he is moving away from the platform and sold the hilux after and onto the turbo diseal v6 Nissan terranos which his one sounded awesome and has two of, had a close look at the head and can't see any cracks will at some point stick a camera inside the pre chamber but I doubt theirs cracks in there. And yea it appears that the block and head still have the mill pattern when it was skimmed with a little bit sealant marks from the head gasket but I haven't tried cleaning em yet and just covered it in grease for now. Will send more photos tomorrow thanks
By dressing the block I mean a light skim to make it flat, but if it still has the milling marks from the previous work that probably isn't necessary. Make sure you use an experienced machine works that can verify the surface roughness is good enough for a multi layered steel gasket. If you can't find any warpage I would definitely not take anything more off the block. If there is still cross-hatching on the cylinder bores and the pistons are still fitted, I wouldn't touch that. If the head is flat I would not do anything to it beyond very careful inspection for cracks and checking that the valve margins and seats look good and seal a vacuum.
However, I'd be a bit suspect of a 'good used head' unless you know the story. These IDI turbos are so prone to cracking heads that it seems odd to dismantle an engine for any other reason (unless maybe it shot a rod through the block, which is also not unknown).
And I would be very, very suspicious of an engine which has clearly been neglected in the past (even one rebuild at 220k is a bad sign) and clearly either severely overheated or run for a long time with a leaking gasket (major machining of block). The fact that it almost immediately seems to have cracked another head strongly suggests there are major problems with the cooling system - coolant passages in the block, water pump, thermostat, fan clutch and radiator should all be treated as highly suspect until checked/tested.
Are their any cheap peak and valley roughness indicaters for sale or are they expensive precision tools and have to go to a machine shop to use theirs?
@dookywagon420 . I saw your question in the Vancouver Island forum. I'm going to delete it there, but am giving some brief response here instead. These days I'm too busy to spend much time helping people on the forums; sorry. Can't even find time work on my own things. Work/family dominates these days. Anyhow, my advice is talk to an experienced automotive machine shop about your questions. They should be able to sort things out for you and give the right advice. That, and keep following the 2LT/3L Factory Service Manual extremely carefully in everything you do.
sorry bit busy with school i will upload photos at some point but I'm still confused by multiple machine shops telling me that by their experience that the 2l,3l is "tough" on the head bolts and need surfacing every time they are apart, they also say the Toyota manual spec of .2mm warpage limit is unacceptable and should be .05mm idk if they are just trying to get more money out of me or if that is actually the case.