TeamSwift

I am building the 98 SOHC 16 valve engine.
Parts came from Rockauto.
Valve guilds are correct.
Engine gasket set is correct.
DNJ Piston rings for stock 74 mm bore are not right. Block bores are 74.05 at there largest measurement.
End gaps are twice as big as the factory manual calls for.
1st compression ring factory calls for 0.006" to 0.011" Checking end gaps in engine I get 0.020" to 0.025".
2nd compression ring factory calls for 0.006" to 0.011" Checking end gaps in engine I get 0.025" to 0.030".
Oil control rings call for 0.012" to 0.020". Checking end gaps in engine I get 0.040" to 0.050".
I am sending these rings back.
What have you used that is correct?
Where did you get them from?

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Fainya
97 Geo Metro LSI,1.3L-GT-DOHC-16v,4.10 5-speed,A/C,170,000,suspension lowered 1",4 wheel disk brakes,15"alloy wheels with 185/50-15 Toyo's,GT bucket seats,analog oil pressure gauge,cruise control, new paint job. 40 mpg at 65 mph.
Good, fast, cheap. You only get two.

what is the ring gap at the very top of cylinder bore (the top portion that rings don't touch)
new ring for standard bore in an engine with used cylinder bore sure will not be on the tight side...

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swift 2000
megasquirt efi
rx7 460cc injectors
td05h-16g @ 18 psi
SRP forged civic piston
suprf1y's 200-335i 210-240e camshaft
1.6 gearbox with swift sport 2007 gear ratios
cusco 1way LSD

Measuring at the top only closed the ring gaps by 0.0012"
cylinder bore gauge shows about 0.0005" taper and out of round
on all of the cylinders. It is why I am only putting new rings in this
engine build. I don't want to build an oil burner by having the ring
gaps to large. I have sent the DNJ reing set back and have ordered
a set that is 0.020" oversized. I will file the end gaps that I need
when the new set get here.

_________________
Fainya
97 Geo Metro LSI,1.3L-GT-DOHC-16v,4.10 5-speed,A/C,170,000,suspension lowered 1",4 wheel disk brakes,15"alloy wheels with 185/50-15 Toyo's,GT bucket seats,analog oil pressure gauge,cruise control, new paint job. 40 mpg at 65 mph.
Good, fast, cheap. You only get two.

i was in the mitsibishi mirage service manual today and came across the ring gap specs 2nd ring gap specs was .006 to .012 new and service limit .03
dont know about suzuki specs...

how many miles on the block? why don't go with suzuki oem parts?

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swift 2000
megasquirt efi
rx7 460cc injectors
td05h-16g @ 18 psi
SRP forged civic piston
suprf1y's 200-335i 210-240e camshaft
1.6 gearbox with swift sport 2007 gear ratios
cusco 1way LSD

For most of the gasoline engine cars we drive these are from the ASE book standards.
From a machinist/engineer point of view, the compression ring end gap is 0.0025" to 0.003" per inch of cylinder diameter.
Oil control rings are 0.004" to 0.006" per inch of diameter.
This is for a newly machined cylinder.
Clearances for cast pistons is 0.0004" to 0.0005" per inch of piston diameter. On the smaller pistons you need 0.005"
minimum to establish and oil film. Anything less will scare the pistons and cylinder walls
Clearances for forged pistons is 0.001" per inch of diameter. Anything more and they will rattle when cold.
I have 0.25 mm rings ordered. I will machine the end gaps to with in these tolerances.

_________________
Fainya
97 Geo Metro LSI,1.3L-GT-DOHC-16v,4.10 5-speed,A/C,170,000,suspension lowered 1",4 wheel disk brakes,15"alloy wheels with 185/50-15 Toyo's,GT bucket seats,analog oil pressure gauge,cruise control, new paint job. 40 mpg at 65 mph.
Good, fast, cheap. You only get two.

If they're the same as the set you have now, .25 mm won't be enough to bring you into spec

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Contact 3tech: [email protected]

The DNJ rings came with both compression rings in chrome/steel.
The ITM 74.25 mm upper compression rings come with 1st compression ring
chrome steel, 2nd compression ring nodular iron. If they also have end gaps out
of spec, I will order the 74.50 mm ring set.
What I would like to have for compression rings are both 1st and 2nd compression rings
made of nodular iron with the 1st compression ring having a Molybdenum disulfide insert
in the ring face. But this may be old school for piston rings today.

_________________
Fainya
97 Geo Metro LSI,1.3L-GT-DOHC-16v,4.10 5-speed,A/C,170,000,suspension lowered 1",4 wheel disk brakes,15"alloy wheels with 185/50-15 Toyo's,GT bucket seats,analog oil pressure gauge,cruise control, new paint job. 40 mpg at 65 mph.
Good, fast, cheap. You only get two.

The 74.25 ring set came in and required grinding the end gaps. The rings unmodified
end gap overlapped. I made a fixture that goes onto my tool grinder. This allows me to get
square cuts on the rings. upper two compression rings where ground to 0.010" end gap.
Oil control rings where ground to 0.015" end gap. Cylinders where micro honed with CBN
stones on a CK10 cylinder honing machine to a piston clearance of 0.002".

_________________
Fainya
97 Geo Metro LSI,1.3L-GT-DOHC-16v,4.10 5-speed,A/C,170,000,suspension lowered 1",4 wheel disk brakes,15"alloy wheels with 185/50-15 Toyo's,GT bucket seats,analog oil pressure gauge,cruise control, new paint job. 40 mpg at 65 mph.
Good, fast, cheap. You only get two.