Low compression on cyl #2, need advice

V

vizi0n

New Member
Hey there guys!

I've compression tested my engine today as it's been running like crap for a while (well, sometimes its ok and runs strong, sometimes its vibrating and doesnt pull and sound A BIT like a Subaru but not that much though). My results are (from left to right): 160-90-160-165. (throttle all the way in, fuel pump off, 5 cranks)

I've poured some oil in #2, did it again and I get 165. To me this looks like piston rings. What's your advice on this? I went for a ride after testing and wow... the car just feels like a new one! It pulls really strong and steady, the engine is smoooooth as silk and it shifts just perfect.

I'd like to know if this is one hell of a job or if it can be done quite easily? And if I get it done should I get new rings for the other pistons as well because they are perfect.

Thanks for your advice and help

Frank

PS: what gaskets will I need for this job? head gasket (cometic .040"), intake manifold, exhaust manifold, anything else? anyone got a set of rings for only one piston or do they always come in package of 4
 
Last edited:
P

pulsarboby

Guest
definately a ring or ringland problem on no2 cylinder!
you will probably find that the bore is damaged and need a full rebore with oversize pistons and rings. if thats the case, it will mean a total strip down matey.
 
V

vizi0n

New Member
i can feel my wallet becoming much lighter in a near future.... I'll buy my parts over winter I guess :( I cant just oversize one piston huh? (looking for the cheap option here! :))

Basically I will need

- Pistons (probably 86.5 or 87mm? -- are all SR20DET pistons the same or do I have to get GTI-R specific?)
- Rings
- Head gasket (87.5mm bore and 1.0mm thick?)
- Valve cover gasket + spark plug holes gaskets
- Intake and exhaust manifold gaskets

So far I'm not planning about anything for the head as it seems to hold up well.

Anything else I should add on the shopping list?
 
Last edited:
Bart GTI-R

Bart GTI-R

New Member
Iv taken my engine out mate and this is the little list I did, from reading different forums and copying and pasting different information and turning it into a list

Re-build list

* Head Gasket (Cometic)
*Rear coolant hoses - TCS111/C-B 4 Hoses
*Water Pump £40 Posted
*Power steering rack bushes (Uprated)
*Engine and Gearbox Mounts (Possible uprated ones)
*Re-con the starter motor about £40 I saved the £40, and replaced the starter brushes myself. Total cost was about £9 from a local auto electrical place, and about a 1/2 hour of my time.
*Master Cylinder seals
*Remove Air-con (Complete)
*Remove Y Bracket and get a front mount
*Check all wiring, cover using heat shrinks
*ARP Head bolts
*Oil Pump re-build
*Clutch Master cylinder repair kit (includes new piston) 306112T025 £16.21 + VAT
*Slave cylinder repair kit for 1990-92 GTIR (3/4" bore cylinder - includes new piston) P/N 3062126E25 £8.38 + VAT (Brought new one)
* Redline 75W90 gearbox oil
* Drive shaft oil seal drivers side - 33142-56E00
* Drive shaft oil seal passenger side - 38342-56E00
• Exhaust manifold gasket---14036-53j00 £14.90Gasket
• Manifold (Throttle Bodies)*
14035-54C00
• Inlet manifold gasket----16175-54c00 £4.40
• Pulley Belt - Water Pump/Power Steering, Nissan, 11950 54C00, Bosch 4PK920 or 4PK919
• Pulley Belt - Alternator (No A/C), Nissan, AY140-40830, Bosch 5PK835 or 4PK830
• Timing Chain
• Timing Chain Tensioner
• Timing Chain Guides
• Replace gaiters
 
P

pulsarboby

Guest
you will have to replace all pistons of the same size, or the engine will be severely inbalanced.
if you just wanna cheap get out then you dont need to do what barts done above.
but you will need head gasket, set of bigend shells and new pistons with rebore
if you go to ericsperformance parts in the states, via ebay, you will get the whole lot for around £400 plus rebore cost which will be about £100
so thats about $1000 dollars in total which will get you out of trouble.

but dont buy anything untill you have checked the bores, its possible that you may get away with just honing them and refitting a piston with new rings, but you wont know till its stripped down.
 
V

vizi0n

New Member
pulsarboby said:
but dont buy anything untill you have checked the bores, its possible that you may get away with just honing them and refitting a piston with new rings, but you wont know till its stripped down.
Click to expand...
that's my main problem as I only have the GTI-R and when the engine is cracked open I wont be able to wait for a few days/weeks to get the parts :(

I've read something about most pistons in the US being not the same design, that they need some changes made to them. Are you aware of that and maybe just show me the differences on a photo or explain them? I guess that if I change the pistons I will probably keep my rods
 
P

pulsarboby

Guest
its not true, ive fitted both cp and wiesco pistons and neither needed machining where the oil squirters are, infact theres a good clearance, so dont believe everything you hear;-)
 
V

vizi0n

New Member
perfect! thats good news as sr20dets pistons are quite common in local tuning shops even if we didnt have these engines in north america.

let's just hope its nothing bad and i can just get the cylinder honed (what's honing? polishing of some sort?) or even better, swap the piston right in without doing anything

would you go with a 1 or 1.2mm head gasket with 86.6mm wiseco's ? i'm looking at a cometic but they only have it in 1.0 (.030") and 88.5mm bore (does that create any problem if my bore would be 86.5 or 87?)
 
Last edited:
P

pulsarboby

Guest
ericsperformance parts have 1.2 cometic gaskets for around £65 delivered to uk which is what you need.
wiesco or cp pistons are available in different sizes, either 86.5 or 87mm, you are better to go for 86.5mm as this will allow another rebore in future should you need it;-)

if you dont need new pistons, you should be able to buy a cylinder honer on ebay, it just fits on a standard drill and has 3 prongs on a spring with 3 grind stones attached which you run up and down the full lengh of cylinder whilst applying engine oil, this takes the surface glaze off the cylinders and allows for the new rings to bed in properly.
think i paid around £25 for mine from my motorfactors!
 
J

jpward

Guest
pulsarboby said:
you will have to replace all pistons of the same size, or the engine will be severely inbalanced.
if you just wanna cheap get out then you dont need to do what barts done above.
but you will need head gasket, set of bigend shells and new pistons with rebore
if you go to ericsperformance parts in the states, via ebay, you will get the whole lot for around £400 plus rebore cost which will be about £100
so thats about $1000 dollars in total which will get you out of trouble.

but dont buy anything untill you have checked the bores, its possible that you may get away with just honing them and refitting a piston with new rings, but you wont know till its stripped down.
Click to expand...

Or just tell him what all you want/need and go direct (ericsperformanceparts@gmail.com) and ask for discount as I have been getting members good discounts for a while now and trying to establish him as a 1 stop shop :lol:

I got Je's but there the same as Weisco's as owned by same company and as bobby said cp's also have the oil squirter provision the main reason fitment problems used to be there, but these are direct fit ;-)


You also say you can’t do without the R hummm most people eventually realise owning an R means a second car is mandatory :p and it can take a few weeks even months to get pistons/rebuilds etc done quickly :?
 
V

vizi0n

New Member
jpward said:
Or just tell him what all you want/need and go direct (ericsperformanceparts@gmail.com) and ask for discount as I have been getting members good discounts for a while now and trying to establish him as a 1 stop shop :lol:

I got Je's but there the same as Weisco's as owned by same company and as bobby said cp's also have the oil squirter provision the main reason fitment problems used to be there, but these are direct fit ;-)


You also say you can’t do without the R hummm most people eventually realise owning an R means a second car is mandatory :p and it can take a few weeks even months to get pistons/rebuilds etc done quickly :?
Click to expand...
thanks for the hint with eric, we`ll see when we get there!

and about the cars, well I have an Eagle Talon too but its got some issues that have been neglected since last winter but its drivable.

and about the rebuild, you say weeks or months? how can putting in new pistons take so long :|
 
J

jpward

Guest
It just seams that with all the best intentions, we all seam to have experienced delays in one way or another!

Unless you are doing the work yourself have the parts to hand and know how to do it before had seams the only way It can be done in a reasonable time!
 
V

vizi0n

New Member
well i'm planning on gathering all parts before undoing anything .. I might as well just bore to 86.5 without a question so I can get new pistons.

Just wondering, is it necessary to change the rods as well? I dont plan on running 500bar, but maybe between 1 and 2 bar.

Are the oil squirters the little holes in the lowest ringland? (These should be CP pistons)
 
P

pulsarboby

Guest
oil squirters are fixed to the bottom of the block on each cylinder,(like little spouts) not brussel spouts though:lol:

the holes on the piston is for the oil controll rings!

your standard rods will be fine, just order a set of arp rod bolts which are about £50!
its the studs that almost always give way before the rods will;-)
 
You must log in or register to reply here.
Top