View Full Version : Urgent - F7R Piston rings and liners
Where can i get some from? and how much?
stan* / BenR - what are the specifications of each. Where can i find detailed information about what they are made from, the type of honing marks etc?
Ive got a plan! :wink:
Can you remove the liners on a steal block, thought they were the actuall block :?
i dunno...is it a steel block flanny boy?
if so any special grade of steel?
no liners in an f7r! :wink:
nope, no liners, solid block mate
Iron block, no liners.
Rings you can get from renault or from any motor factors/engine machine shop.
What they are made from.........ductile iron......might vary a little between OE and pattern manufacturers.
IF your feeling fancy you can buy aftermarket rings of the correct sizes in varying irons/steels/coatings etc.
Honing........i wouldnt even worry yourself, it took me ages to find someone who can hone a bore straight and round and offer different hone RA's and hatch angles, and plateu honing.......and its not cheap.
ok, cool. cheers Ben. I owe you!
can you recommend any performance ring kits for the f7r with thermally sprayed ceramic coatings?
i know you can get loads of different molybdenum composite coatings that can be thermally sprayed onto rings but is there any manufactures that do off the shelf rings. i suppose its just finding a ring with a 82.7mm diameter, but any pointers.
i know of Poeton which do thermal coating for rings, liners, crankshafts, valve train components etc, but would rather get an "off the shelf" ring if i can help it.
also does anyone have any idea how expensive a piston ring kit from renault would be?
this is all awesome help. much appreicated.
about £40 per cylinder for a ringpack.
There are plenty of people you can buy rings from, there are manufacturers of just performance rings, or buy off piston manufacturers who buy off the same people.
Run a different or fancy coating and you'll have to adapt the hone finish, which as i said is near impossible in the UK unless your willing to pay over £200 for just a hone job.
If you look for off the shelf rings from say total seal, then you'll have to match every dimention from inner and outer dia, thickness, depth, ring type (dykes, napier, gapless, barrel), radial wall. Coatings help dependant on cylinder wall material, periphery coatings to stop micro welding, not that its an issue for you.
And after you've spent a week researching..........whats the gain?
Total Seal to name one.
I would definately hone the bores if your fitting new rings.
or is this part of you project work?
all project work guys.
so all theoretical and stuff.
cylinder wall wont be honed, probably just polished. ill get on the fone to renault and see what they can do in terms of rings. i really only need two rings in total.
stan*/BenR - are the two pressure rings identical on the f7r engine? with the 3rd (oil control ring) different?
if so i only need one ring kit! :twisted:
are coated rings mega bucks?
no they arent identical, they often have a different profile.
you can buy just 1 piston set if you want.
I dont know if you can buy a single ring outside a ringpack.
polished bore?
1st and 2nd comp rings are now the same, originally different.
ok cheers.
well the bore will be made up from a machined bit of iron, so will be polished, but i very much doubt honed. :?
thanks for all the info so far guys....
more questions to follow no doubt!
how can you test rings then, as they are designed to work on a honed finish.
Ideally you want to hone then plateu hone to replicate a run in bore.
What i suggested:
Buy a cheapo test engine e.g. CVH to run on the uni dyno.
Strip it, and build using 4 different ring combo's...one on each of the bores.
Fit a cylinder pressure transducer to each cylinder.
Run on the dyno at a set load/rpm.
Log peak cyl pressure, and compare between each cylinder.
Obviously there are assumptions e.g. that each cylinder has the same mass burnt/unburnt fraction, that each cyl has the same airflow and fuelling values...blah blah
But i think this is a far more realistic test.
The only isue would be if the pressure variation across the cylinders is actually measurable...i.e. if the mechanical changes you are making are having THAT much of an effect.
how can you test rings then, as they are designed to work on a honed finish.
Ideally you want to hone then plateu hone to replicate a run in bore.
will speek to kenny our machinist tomorrow. im sure he will work something out!
hehe
ok, this is all good to go, except i need to get somewhere i can purchase 82.7mm bore liners. the rig has to have liners, as we cant simulate the cast block cyliner wall otherwise. :cry:
any ideas?
then get any iron liner and bore/hone it to size.
you have to do some work, you cant buy everything off the shelves! lol
:cry:
ohh well.
any ideas of liners that are similar? im sure that most 2.0l engines have similar bores, so....
the F7 has a small bore for a 2.0.
You dont need it to be strong, just get any liner that has an ID that is smaller and bore/hone it to size.
use a 5gtt liner
ok, but will the 5 gtt liner fit the ring with a diameter of 82.7mm?
no...........you have to bore it then hone it to size........
explain ben i dont quite get ya....
:oops:
you wont find a finished liner in 82.7mm easily......
So, get a liner off a 5gtt which has a smaller bore, then machine it to the correct bore (boring machine) then hone it to finishing size and required hatch.
perhaps easier to get 5 gtt rings as well then. shame, i wanted to do the williams engine! :cry:
outa interest what is the bore of a 5 gtt?
and the material composition of both the liners and rings used in the r5 gtt engine, oh wise one?
(many thanks Ben - much appreciated!) 8)
dont know.........wont touch the POS things.
Liners are iron though, dont know if they are grey, ductile etc?
ok, many thanks. need to speak to my machinist and see if we can get a liner machined to the correct bore.
do renault still sell liners and rings for the r5 gtt?
wtf?
if your getting a 5gtt rings then you wont need to machine it, as they come finished.
make up your mind man!!!!!!! :P
hehe
i want to use f7r rings if i can, hence will need to speak to my machinist, but if thats impossible will use r5 gtt rings!
all up in the air just now.
many thanks for all your help ben! 8)
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