Need to strip my engine cos' either the rings or ringland have gone in cylinder 1. If I buy new rings/pistons/both, will the bores need rehoning? Provided the bearings are in good nick I was planning to re-use them, obviously replace if knackered, but can't afford to replace too much at the moment. Was also considering just getting a new engine, has anyone used SMR engines who advertise on Fleabay? They quote a guaranteed mileage engine, fully refurbished with new bits where required, for around £700. Not sure which is the best route to go tbh. Haven't got the tools to remove and engine!
Is honing absolutely necessary?
- Thread starter mork
- Start date
350ep70gr
Member +
MARK@CMBAUTOS
Trader
smr engines r a no go:haha:
350ep70gr
Member +
MARK@CMBAUTOS
Trader
they dont recon nothing, they take them out and give them a wash and a paint and claim they are reconed.:haha:
Dave@TM-developments.com
Trader
You need to hone the cylinders for the rings to have a surfave to bed in. Don't listen to anyone that says you don't. Toyota rings are no different to any others
gorganl2000
Lifer
i've seen engines rebuilt without honing if there was no major problems with the engine in the first place....kind of like if your piston ringland was broken and no other damage or just a partial overhaul/rebuild.....in these cases, genuine toyota parts were used
while some builders will want to hone/refresh or rebore the cylinders regardless
i guess its just preference in certain cases
NOW if your cylinder has any signs of wear, then it should be properly checked and the appropriate action taken
in the case of forged internals,,,honing seems to be necessary...for rings to seal/seat properly....but the guys who run aftermarket pistons/rings would be better able to advise
while some builders will want to hone/refresh or rebore the cylinders regardless
i guess its just preference in certain cases
NOW if your cylinder has any signs of wear, then it should be properly checked and the appropriate action taken
in the case of forged internals,,,honing seems to be necessary...for rings to seal/seat properly....but the guys who run aftermarket pistons/rings would be better able to advise
Last edited:
I must admit smr seem like bullshit almost every engine they have has 30 odd thousand miles lmao.
Starletto_Joz
Member +
I'm in the process of having my FTE rebuilt also mate. Having opened it up, we could see all the bearings need replacing. As I have the full gasket set, everything will be used to rebuilt the head inc. valve stem seals etc.
I did contemplate not changing the piston rings as they looked clean/spot on and the engine compression is good. The engine also pulled well when it was running.
But with the mileage (120k) its not a good way to 'visually' judge the rings don't need replacing just because they are clean so I'm changing the rings now as well for peace of mind that the engine will be totally rebuilt.
Thanks to Jay I'll be having my crank taken to be polished and my block inspected and then honed if necessary (for the same reason dave mentioned, so it has the right surface to accept new rings) the only reason an overbore would be needed is if upgrading to forged pistons or if there is damage/warping to the cylinders that can only be seen by specialist equipment and material needs to be taken off.
I hope this helps from a different point of view mate. If you are on a budget save up until you can afford to rebuild everything for the ultimate peace of mind. Components such as rings aren't cheap but in the long run you know once installed properly that they are not going to let you down, and that you will not need to open the engine to do the rings again later down the line rather than sooner.
Do it once, do it right
Joz
I did contemplate not changing the piston rings as they looked clean/spot on and the engine compression is good. The engine also pulled well when it was running.
But with the mileage (120k) its not a good way to 'visually' judge the rings don't need replacing just because they are clean so I'm changing the rings now as well for peace of mind that the engine will be totally rebuilt.
Thanks to Jay I'll be having my crank taken to be polished and my block inspected and then honed if necessary (for the same reason dave mentioned, so it has the right surface to accept new rings) the only reason an overbore would be needed is if upgrading to forged pistons or if there is damage/warping to the cylinders that can only be seen by specialist equipment and material needs to be taken off.
I hope this helps from a different point of view mate. If you are on a budget save up until you can afford to rebuild everything for the ultimate peace of mind. Components such as rings aren't cheap but in the long run you know once installed properly that they are not going to let you down, and that you will not need to open the engine to do the rings again later down the line rather than sooner.
Do it once, do it right
Joz
350ep70gr
Member +
In an old engine i would be more sceptical if i would hone and add .002 more clearence between bore and piston/rings.
Anyway.. i prefer honed surface aswell but with cast iron rings you can avoid it if you like.
Chris
Well, I was looking at the Total Rings instead of Toyota, but that might lead to more problems I guess, seeing as they're aftermarket. From what I know about the history of the engine, it's only done 40k or so, but was apparently thrashed a bit by a previous owner. Anyway, with only 30psi on one cylinder it's gotta be done. Although at such a low compression, it may well just be a piston ringland that's gone. All valve stem seals were done in 2007, head skimmed flat, general overhaul, but nothing done to the bottom end. All the other plugs are super tan colour, look spot on, just this one that's oily. If it's the piston, can I get just one or is it best to do the job lot, seeing as it's stripped down anyway?
What damage could be done if I continue to use it though, even though it's only used occasionally as it's a long-term project anyway (actually a Sera with the turbo conversion, so pretty rare).
Thanks for the advice guys, looking more expensive by the minute!!!
What damage could be done if I continue to use it though, even though it's only used occasionally as it's a long-term project anyway (actually a Sera with the turbo conversion, so pretty rare).
Thanks for the advice guys, looking more expensive by the minute!!!
HYBRID
Super Moderator <a href="http://www.toyotagtturbo.
total seal rings are best used on forged pistons, they increase cylinder pressures alot more, but give the best sealing possible. on my old setup i had ross forged 74mm pistons with ross rings, with some homemade honning.. the result was ok, but the rings never seated 100% with the block as the honning was not crossed/angled propperly, not to mention the pistons where 2nd hand, so the rings where gapped to the specs of another engine. now on my new build (the one i did 2 years ago) i did everything propperly, needless to say i took it to the engineer to get it honned, now this time i was still using my ross 74mm pistons as they where still practically new, but since she was getting a fresh honning i went for total seal rings, as racing wise they are the best, with no chance of compression escaping.
The engineer explained to me that the running in period is basically the rings scraping the honning off till it is smoth & to the clearance of the new rings, it is THE most important thing to do when installing new rings as otherwise ur new rings may not seat propperly to the bore & ull get the occasional puff or lower compression readings/higher crank case pressure.
One thing about total seal rings is prepare to add a few breathers on the top cover, when i had just one breather i used to find the catch can half full every two weeks, (with fumes/vapour not oil lol) when i asked around its coz of the rings giving a perfect seal & thus oil compression is much higher, so to aid the engine breath adding breathers is the best thing to do, not to mention eliminating the pcv.
So to answer ur original question, yes it is IMPERATIVE that u honne the block when installing new rings
Hope my little story helps.
Kon
The engineer explained to me that the running in period is basically the rings scraping the honning off till it is smoth & to the clearance of the new rings, it is THE most important thing to do when installing new rings as otherwise ur new rings may not seat propperly to the bore & ull get the occasional puff or lower compression readings/higher crank case pressure.
One thing about total seal rings is prepare to add a few breathers on the top cover, when i had just one breather i used to find the catch can half full every two weeks, (with fumes/vapour not oil lol
) when i asked around its coz of the rings giving a perfect seal & thus oil compression is much higher, so to aid the engine breath adding breathers is the best thing to do, not to mention eliminating the pcv. So to answer ur original question, yes it is IMPERATIVE that u honne the block when installing new rings
Hope my little story helps.
Kon
Dave@TM-developments.com
Trader
Thanks Kon, someone else that understands the importance
HYBRID
Super Moderator <a href="http://www.toyotagtturbo.
Thanks Kon, someone else that understands the importance
Anytime Dave
There is generally one rule we follow here: Do it once, do it right, or dont bother doing it at all
Kon
i would deffinateley agree with this at a minmum i would give it a hone
its fairly cheap , or even cheaper if you know someone with a honeing tool
dan
As above, also check the ring gaps.
You need to hone the cylinders to get the rings to seal.
350ep70gr
Member +
Hey kon you do know that second hand rings was your prob and not your diy hone proccess.Hone specs/cross hatch at specific angle is for lubrication propose of the rings and for cleaning the tinny particles fast from the bore. When they first heat up they are pressed against the bore and stabilize there while you repeat hot/cold changes mean accelaration/decelaration...(which happened in the previous owner and engine)
Before you deside if you will hone or not you need to mesure the bores or else you maybe end off with an engine worst than what it was in the first place.i would deffinateley agree with this at a minmum i would give it a hone
its fairly cheap , or even cheaper if you know someone with a honeing tool
dan
If the engine is worn like out of round or exxessive clearence and you add some hone your end gap of the rings will be huge. If this gap is more than specification then your engine will be worst for sure.
Dont just listen who ever tells you, you need to do that or the other proccess!
Take your time ..make your mesurments..compare them with the oem specs table and deside from there..
Honeing isnt always the best you can do..it depends the engine condition.
FRESH AND HONED BORE IS ALWAYS BETTER TO WORK WITH. But you dont get the fresh bore always with a hone proccess.
Sorry to the gurus but this is how things are...
Learn to speak with numbers and when it comes to advice someone at least tell him that if you are from this number to this number you can hone or what ever.And if you are more than this you need a rebore.. or else your engine will be breathy and have piston slap no matter what..Friendly
Chris
Last edited:
Hey kon you do know that second hand rings was your prob and not your diy hone proccess.Hone specs/cross hatch at specific angle is for lubrication propose of the rings and for cleaning the tinny particles fast from the bore. When they first heat up they are pressed against the bore and stabilize there while you repeat hot/cold changes mean accelaration/decelaration...(which happened in the previous owner and engine)
Before you deside if you will hone or not you need to mesure the bores or else you maybe end off with an engine worst than what it was in the first place.
If the engine is worn like out of round or exxessive clearence and you add some hone your end gap of the rings will be huge. If this gap is more than specification then your engine will be worst for sure.
Dont just listen who ever tells you, you need to do that or the other proccess!
Take your time ..make your mesurments..compare them with the oem specs table and deside from there..
Honeing isnt always the best you can do..it depends the engine condition.
FRESH AND HONED BORE IS ALWAYS BETTER TO WORK WITH. But you dont get the fresh bore always with a hone proccess.
Sorry to the gurus but this is how things are...
Friendly
Chris
with regards to the hone process and the finish you get does that not depend on the stones used and the order there used in ?
dan
Texx
Super Moderator
Ideally when fitting new piston rings the cylinder bore will need honing. However, as Chris has said it's not just as simple as honing the cylinder and then slapping new pistons and rings in. You need to take the relevant measurements before deciding what actions need to be taken.
After removing the ridge at the top of the cylinder, you need to measure the piston oil clearance to identify if the cylinder bore can be reused with an original diameter piston. This is done by measuring the diameter of each cylinder bore at 3 places in the thrust and axial directions, approx 10mm from the top, 10mm from the bottom and then in the middle. The measurements have to then be compared to the specification for the relevant sized bore. You should be able to identify the original cylinder bore size by looking at the markings stamped on the block face next to each cylinder or the corresponding markings on the piston crown. I'm not sure if the 5E spec can be used, but as an example:
Size Mark 1 = 74.000mm - 74.010mm
Size Mark 2 = 74.010mm - 74.020mm
Size Mark 3 = 74.020mm - 74.030mm
Before deciding whether a cylinder can be reused, you need to take into account a further diameter increase from honing. If any cylinder diameter measurement is close to 74.030mm at either of the 3 points measured, then you will need to consider a re-bore as honing will likely render that cylinder useless when used with a stock sized piston. If the diameter of each cylinder is well within specification, then you can proceed with honing. Once honing has been carried out, the above measurements will need to be taken again and noted for later reference.
Now we come to the pistons. If you are intending to reuse the pistons that were originally removed, you can go ahead and measure the diameter of the piston skirts in the thrust direction, approx in the middle of the piston hight just below the lower ring groove. For reference, the 5E spec for stock piston diameter is:
Size Mark 1 = 73.900mm - 73.910mm
Size Mark 2 = 73.910mm - 73.920mm
Size Mark 3 = 73.920mm - 73.930mm
Then subtract the piston diameter measurement from the corresponding cylinder bore diameter measurement to identify the piston clearance for each cylinder. Again going by the 5E spec, the original clearance would be 0.090mm - 0.110mm and a maximum clearance of 0.130mm. If you have measured a clearance close to or greater than 0.130mm then you will need to use a larger diameter piston in that cylinder i.e. if you removed a size 2 piston you will need to fit a size 3 piston and then take the above measurements again to calculate if the piston clearance is within spec. If you have a near or excessive piston clearance with a size 3 piston, the block will require a re-bore and new pistons purchased to suit. Once you have 4 matching cylinders and pistons the rings can then be gapped to suit.
So in summary, yes honing is required with new piston rings, but it's far from as simple as honing the cylinder bore and fitting new rings. If you go and buy new pistons and rings thinking you can just slap them in and jobs a good'en, then find your block requires machine work, you'll have wasted money on a set of pistons and rings that will no longer match your engine.
After removing the ridge at the top of the cylinder, you need to measure the piston oil clearance to identify if the cylinder bore can be reused with an original diameter piston. This is done by measuring the diameter of each cylinder bore at 3 places in the thrust and axial directions, approx 10mm from the top, 10mm from the bottom and then in the middle. The measurements have to then be compared to the specification for the relevant sized bore. You should be able to identify the original cylinder bore size by looking at the markings stamped on the block face next to each cylinder or the corresponding markings on the piston crown. I'm not sure if the 5E spec can be used, but as an example:
Size Mark 1 = 74.000mm - 74.010mm
Size Mark 2 = 74.010mm - 74.020mm
Size Mark 3 = 74.020mm - 74.030mm
Before deciding whether a cylinder can be reused, you need to take into account a further diameter increase from honing. If any cylinder diameter measurement is close to 74.030mm at either of the 3 points measured, then you will need to consider a re-bore as honing will likely render that cylinder useless when used with a stock sized piston. If the diameter of each cylinder is well within specification, then you can proceed with honing. Once honing has been carried out, the above measurements will need to be taken again and noted for later reference.
Now we come to the pistons. If you are intending to reuse the pistons that were originally removed, you can go ahead and measure the diameter of the piston skirts in the thrust direction, approx in the middle of the piston hight just below the lower ring groove. For reference, the 5E spec for stock piston diameter is:
Size Mark 1 = 73.900mm - 73.910mm
Size Mark 2 = 73.910mm - 73.920mm
Size Mark 3 = 73.920mm - 73.930mm
Then subtract the piston diameter measurement from the corresponding cylinder bore diameter measurement to identify the piston clearance for each cylinder. Again going by the 5E spec, the original clearance would be 0.090mm - 0.110mm and a maximum clearance of 0.130mm. If you have measured a clearance close to or greater than 0.130mm then you will need to use a larger diameter piston in that cylinder i.e. if you removed a size 2 piston you will need to fit a size 3 piston and then take the above measurements again to calculate if the piston clearance is within spec. If you have a near or excessive piston clearance with a size 3 piston, the block will require a re-bore and new pistons purchased to suit. Once you have 4 matching cylinders and pistons the rings can then be gapped to suit.
So in summary, yes honing is required with new piston rings, but it's far from as simple as honing the cylinder bore and fitting new rings. If you go and buy new pistons and rings thinking you can just slap them in and jobs a good'en, then find your block requires machine work, you'll have wasted money on a set of pistons and rings that will no longer match your engine.
Last edited: