Back with some question (engine)

fiatboy

fiatboy

True Classic
Work a little bit on the engine this week-end

New polyurethane bushing for the dog bone



next dismantle the engine and mesurement
crankshaft journal and main on spec (standard)
have to change bearing

cylinder in spec between 86.001-86.030 no out off round no tapper(0.0001)





piston in very good shape and in spec
1-2-3 are 2495C 85.94 on spec
4 are 2495E 85.96 on spec

ring are out
thickness exemp cyl 1 ring 1 spec 1.478-1.490
reading 1.423
ring 2 spec 1.978-1.990 readiong 1.874

ring end gap (photo not clear) for all cylinder the ring gap in cylinder was about 1/8 or 3.175mm suppose spec 0.45mm

the spec for the piston ring groove width dont match with my piston
the groove for all my piston are
1 1.71 spec 1.535 to 1.555
2 2.03 spec 2.030 to 2.050
3 3.93 spec 3.967 to 3.987




the crankshaft front cover where are the seal the hole is out of round normal or not


before I unbolt the connecting rod from crankshaft I remark a little movement( at the journal) from front to back of the rod for all 4 piston (slide front to rear but thousand of an inch)







 
Last edited:
This main bearing are install on my engine???
is the 1500 and 1300 have same bearing
I dont know if this one are standard or oversize but the crank mesurement are in spec



list on e-bay
Fiat 124 Spider 1500 Sport BS Hauptlagerschalen Axiallagerschalen 4130442 41304
stamp on the shell 4130442
look to be the same with the trust half ring

when i try my car they said
This item does not fit Fiat X 1/9 1974 128 AS 1.3.
 
We sell bearings, rings, and pistons too. As do some others on here that know these cars and we all sell parts that fit. Check our site for lots of goodies.

The front seal cover shouldn't have an egg shaped hole. That was from it being installed wrong. Probably made noise years ago till the crank ground it down. Replace it or don't. Doesn't really matter as the seal will center on the crank snout. Just tighten things carefully.

The rods have some play front to back or they would rub on the crank throws.
 
...

fiatboy said:
this photo from midwest the hole seem not round

Click to expand...

That's the rear (flywheel end) crank seal holder/cover plate, the one you showed from your car looks to be (a rear view of) the front (pulley end) crank seal holder/cover plate?

Regardless, the hole is supposed to look like that - it's factory original & not due to it being installed wrong or the crank grounding it down. The center hole's not oval- or egg-shaped, it's a circle with 3 small "feet" around the perimeter spaced 120° apart. The crank seal fits within the larger bordered circle just outward of the hole, the V-shaped slot at the base of the cover plate hole is an oil feed/return port for the seal.

The Fiat 600D & 850 engines have a similar feature on their crank seal holders/covers, but probably a bit more noticeable than on the 128-X1/9 parts:

850tcc1b.jpg
 
Sounds like you need new pistons/rings as the top ring grooves are excessively worn and the ring end gap is enormous.

If your going to fit pistons, then it's usually best practice to rebore the cylinders, and start with a nice round hole... I find it hard to believe that the cylinders will be OK between corrosion and wear to even consider using 86.0 mm standard size.

your low compression was definitely a combination of valve and ring seal, if you shop around for parts and do a lot of the cleaning and r&r yourself it shouldn't be too expensive to put right and end up with a reliable engine

124 OHV and small journal twin cam uses the same bearing shells as the 1300... those you should find very easily.

Seal cover is OK...the mounting bolt holes have a bit of clearance so the seal can be aligned to centre on the shaft.

SteveC
 
Thanks for the reply

took off little ridge on top of each cylinder only by emery 220 and no more ridge

most larger cylinder no 2 at top 86.0421

steeve do you know why cylinder are all in spec +- 0.001 piston are all in spec +-0.001
and end ring gap are so far from spec

worn ring ???? not the good one????


foe mesuring the piston it's suppose to be mesure 27,5mm down from the top
is it possible the piston is on spec at 27,5 and tapper on top or worn and it's why big end ring gap

someone know the bore side clearence with piston in bore?
 
After 2 days of sanding with aeronotic engine sanding paste
no more corrosion or pitted on cylinder no 1
no rigde at all
all cylinder under spec bigger one 86.421mm at top
no out of round<
no tapper

order at midwest
main bearing
rod bearing¸
rings
seals
will do a compression test on bench

next time photo
 
You measured for out-of-round - what were the bore measurements fore/aft and front rear for each bore? Typically the wear will be fore/aft that causes out-of-round.

How many miles were on the engine?
 
I hussein
My mesurement was take 3 times each pass top center and bottom
And for each x pattern
Total 144 mesurement

The car have only 80,000 miles
But was store for the last 20 years

The corrosion that
I see in cyl no 1 was something who was drying in the cylinder for few years but very easy to took off with the aeronotic engine sanding paste and honning after
 
You still have an excessively wide top ring groove in the piston... so the ring won't work or seal properly.












SteveC
 
I forget to tell you steve
My mesurement was wrong for the groove
I try to mesure it with a special micrometer for aviation but the micometer
wanted go to the botton of the groove

I'l recheck all my groove with a filler gauge and everything are in spec
I do plastigauge for the bearing standard on spec
 
That's OK then.... just follow the steps from the workshop manual (but remember it is written for an 86.4mm bore, so just take 0.4mm off the bore spec sizes) for ring end gap and side clearance and get some plastigauge for the crank clearances... sounds like the engine has minimal wear and should come good with a re-ring for the bottom end.

Might pay to change simple things like the cooling gallery core plugs as they are easy to do now, but a PITA once the block is back in the car...and definitely fit a new waterpump (it's cheap insurance)

Strip the head (or use the spare) and I can try find and post the appropriate pages for various clearance and size measurements for you...mainly stem size, guide clearance and seat finish is what you need to worry about

buy yourself a valve lapping tool (suction cup on a stick) and medium /fine valve grinding/lapping paste.

SteveC
 
Thank you very mutch Steve very appreciated

Next step make my spare head a new one
I buy a spring compresseur and a lapping tool
First look the valve seat look good

The water pump look like something who was change the day before the car was stored for 20 years!like a new
 
fiatboy said:
The water pump look like something who was change the day before the car was stored for 20 years!like a new
Click to expand...

If you're sure it's good, then you can keep it. Just do remember that replacing it when the motor is in the car is a lot more work, so you're taking a bit of a calculated risk here.

Even if the pump looks good, you still have to check the impeller clearance while everything is apart. If the impeller clearance is not right the car won't cool properly.
 
piston clearance

I said it once here on the forum....now again. look for an a b or c stamped on the piston and a corresponding mark at the base of the block where the pan fits. the tolerances weren't so precise as they are now. if the bore was oversized (during original build) they used different pistons to placate that. and rings as well.
mikemo
 
ok gonna check for the impeller clearence with cover
like I said I think the pump never pump 1 once of antifreeze

pistonclearence

got 3 piston mark 2495 c and are on spec with the fiat spec 85.960 to 85.970
1 x 2495 E and on spec to 85.9801 to 85.990
 
fiatboy said:
ok gonna check for the impeller clearence with cover
like I said I think the pump never pump 1 once of antifreeze
Click to expand...

Wait - you've rebuilding the engine and relying on a pump thst is at least 20 years old? Doesn't matter whether it ran or not - might be better if it had - the seals will dry rot over time.

If it was stored for so long, presumably you are replacing all the hoses, etc ?

Probably brake & clutch parts will be iffy to...
 
Your right Hussein
gonna keep it for parts

new water pump
new clutch and pressure
new brake and disk
 
The bock is ready

the cylinder head clean up new valve and lapping
check block and head for straightness ok

I have to block the 2 small port on the head for cooling the carb what do you use for this
tap thread 1/8 npt and a plug with no head
 
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