I've got to replace the rings on my Pinto, as very low compression (<100 PSI80 on one). Confirmed with oil through the spark plug port pushing PSI up to 200+.

My question is two fold:
1 - When I replace the rings, is this the only replacement part required (excluding head gasket and head bolts).
2 - Depending on the answer to 1 is it worth trading it in for a reconditioned block instead to take away the hassle.

Note: I don't have any of the tools required (Honing tool, ridge reamer,Ring Compressor, Engine Stand) to replace the rings yet, so just weighing up what to do. Tools and Rings could cost up to £200 in total

Advice or alternative options appreciated?

Thanks
Rob

In order to get the pistons out of the cylinders you will have to (at least) undo the bearings on the crank. Therefore it would be a good time to consider replacing them as well. this will of course depend on how many miles your engine has done, whether it has recently been rebuilt etc.

Usually this will entail removal of the sump so the sump gasket will need replacing. Unless the engine is very low mileage or recently rebuilt, I would replace the crank bearings as well.

In short, you will probably need a full gasket set. Also new oil filter etc

Depends on the age of your Pinto whether the head bolts can be re-used.

Piston ring compressor is pretty well a must-have for this sort of job. You should hone the bores to allow the new rings to bed in properly.


All the above is just a quick reply - it really depend what sort of standard you want to avchieve

Full Gasket set assumed.

Bearings would add another £40 minimum to the cost. Would these be a straight whip out and replace job - or does it become more technical than that. Could I get it wrong?

I doubt the engine has been rebuilt previously.

Manoeuvrability is a big concern. Trying to work out whether I can leave the engine in the car and work from underneath?

You should perhaps have a think about upgrading to Zetec or even better Duratec.

if the rings are worn then there is a fair chance that the pistons are past their best too. - you might even need a rebore.

best to take it apart and have the block and pistons inspected by an engineering shop. they will tell you what you need.

just replacing the rings on a worn engine is a lot of work and might not cure the problem.

quote:

---

Originally posted by big-vee-twin
You should perhaps have a think about upgrading to Zetec or even better Duratec.

---

First thing I would do is get a Haynes manual (one of the old ones) and have a read through - that will give you an idea of what's involved.

Changing bearings etc is straightforward.

You will need a torque wrench for putting the engine back together.

I agree that the engine may have wear in the bores- you might need to check the measurements of the crank journals as well

I think that upgrading the engine will introduce even more cost (Eg change of exhaust headers).

I can't say whether the engine work can be done in situ as my cars are totally different to the locost chassis but it will certainly be easier (for a first time) to work on the engine out of the car.



It all depends on what you want to achieve and what your budget is.

My first engine work was a Rover V8 and I managed to do it with a Haynes manual. You may be able to get away without as there is a lot of info available on the internet and the Pinto is a common engine. Very satisfying when you've done it.

I was able to take parts into a local engine builder and get him to check tolerances fore me - the power of a few quid for the tea fund goes a long way

If you can get the sump off in situ then you can easily replace the big ends and rings in the car, you need engine out if changing the mains.

Take the head off, drop the sump, undo the big ends making sure you note the orientation and number, i.e. no1 goes back into no1 hole with the con rod and piston point ing the same way (draw an arrow and number on the piston and big end cap).

You will need a splined tool to undo the head bolts, apart from that everything else can be removed with a decent socket set and piston ring tool.

You may find a broken ring caused by overheating maybe?

That aside you will need to glaze bust the bores, you can get honing tools for this or if money is an issue then use some 240 grade wet and dry to break the surface, rub around the bore, never up and down, rub until you see the surface is evenly roughed up.

Should be easily do-able for £100 really.

Initially run on castrol GTX, not a synthetic oil and after it's been running for an hour apply 5 second bursts at full power then foot off for ten seconds building up the revs over an hour or so to quickly bed the rings in before SVA (power pushes the rings into the bores, foot off relaxes them allowing oil to better lubricate)

Regards Mark

Thanks Mark.

Pricing everything up now

AND if you do it don't forget to change the oil pump, might as well if you are changing the rings and shell bearings

Likely not wanting to hear this.
Pint-os were Crap engines. They ate their innards.
Likely the thing will need a rebore/ fresh rings/pistons a crank regrind /All new bearing shells an oil And water pump As well as a head rebuild. And of course all new gaskets and seals. A bit more than Beer money.
For what? wee poor power, semi reliability ?
As mentioned; Splurge for something from the later half of the 20 century.

For a cheap fix deglaze bores check ridge and remove fit rings don't worry about bearings if they don't knock
Perhaps a replacement engine would be cheaper and rebuild old one in slow time

quote:

---

Originally posted by snapper
For a cheap fix deglaze bores check ridge and remove fit rings don't worry about bearings if they don't knock
Perhaps a replacement engine would be cheaper and rebuild old one in slow time

---

quote:

---

Originally posted by Bare
Likely not wanting to hear this.

---

Things to check to help you decide what to do.
1, The bores are not oval, if so waist of time doing it will need a re-bore.
2, Size of bores to get correct rings. ( Could be stamped on pistons)
Now for new parts.
Head set, may as well change valve stem oil seals and lap valves in why head is off.
New head bolts.
Sump set, inspect oil pump while sump is of.
New big ends.
New good quality piston rings. (De-glase the bores this is a must so rings can bed in)
Check camshaft while head is of as well.
Clean pistons so rings move freely and no crap behind oil scraper ring.

Keep all parts as clean as possible when building engine up. I say this because i went around a friends house to help his with his engine build. He was building it up on a bench he had been grinding on, of coarse i set him straight.
But just goes to say it does happen, sorry to go on about it but i was astounded.

When I was a skint teenager we used these....

Std Cords Piston Rings - 1593cc Capri , Cortina Pinto Engines

The "ring dodger" meant that you could fit them to a completely knackered block. These and a gasket set - worth a try before buying an engine that somebody else tells you is fine.

So- Here is what I have been able to pull together based on cost - Just ballpark

To Replace the rings (Between £140 and £205)
- New Tools (Ring Compressor - £10,Honing Tool - £14,Ridge Reamer - £20) = £44 (say £50)
- Parts Mandatory (Head Gasket - £10, Head Bolts - £15, Rings - £50, Sump Gasket - £11) = £86 (say £90)
- Parts Optional (Bearings and ThrustWashers - £30, Oil Pump - £20, Timing Belt - £12) = 62 (say £65).

Reconditioned Cylinder Block (Up to £450)
- Cylinder Block (Reconditioned £400)
- Parts Mandatory (Head Gasket - £10, Head Bolts - £15) = £25
- Would be able to sell some of the existing parts (Sump Pan - £20)

Convert to Zetec (Ignoring Duratec as way too expensive)(£350 approx net of sold parts)
- Second hand "running" 1.8 Zetec - £175
- New Exhaust Manifold - £200
- Alternator Bracket - £40
- New Starter Motor - £50
- New Clutch - £50
- Various other parts which I'm not sure would actualy be needed (seen on list and forums alike) - £150
- Would be able to sell current SS Exhaust Manifold - £100, Head with Vernier Pulley - £100, Standard and Fast Road Cams - £50 each, Pinto Sump Pan - £20
- not sure I've caught all the costs here in this option.

My feeling is to go with the cheaper replace rings route c.£140 I.e. don't replace bearings and pump, with a view of targeting the Zetec conversion in the future, by which time the Duratec costs may have come down enough to warrant looking at.

Let me know if you think I have missed any costs out here.

quote:

---

Originally posted by Bare
Likely not wanting to hear this.
Pint-os were Crap engines. They ate their innards.
Likely the thing will need a rebore/ fresh rings/pistons a crank regrind /All new bearing shells an oil And water pump As well as a head rebuild. And of course all new gaskets and seals. A bit more than Beer money.
For what? wee poor power, semi reliability ?
As mentioned; Splurge for something from the later half of the 20 century.

---

Pistons are out... Cleaned and Rings removed

Lip on ridge around top is very shallow. All bores smooth throughout. So presume no need for a rebore and standard Rings would suffice

On Pistons I can see where they have been leaking - black staining on Piston between some of the rings.

Big End shells feel very thin - so will look to replace whilst off, although not sure whether they are well worn or not until I get a new set.

Oil black rather than brown, but needed replacing anyway.

Well done! Oil would be black with half the exhaust gas charging past the rings... There is no way on earth that you can gauge the wear on the bearings by assessing "thickness". Stick a new set in - nowt to loose but the price of them.

Do not forget to look at your pistons/bearings for any stamps/part numbers that might indicate that there had been a previous rebore/regrind

Marks on Pistons as follows:

Front $
Rear "24"
Right side Large "2" and small "Y6L"

Is that all standard?

Also should the rings be tight in the groove.
There are two set options:
My groove width is 2mm,2.5mm,4mm.

This matches the early ring set, but the later ring set is 1.6mm,2mm,4mm which would make them loose in my grooves?

Engine code is NAT/LA.... which denotes 1990 - Is that "Early" or "Late" - I suspect late.



[Edited on 14/10/13 by RobBrown]

For info, and anyone reading this later:

Replaced Rings and Big end Shells - Cost a total of £140, which included a ring compressor and honing tool.

Advice to those wanting to do this:

- If you can do it with the engine out of the car, or get the front of the car as high as you can. I'm over 6 feet 2 and struggled with my fat fingers and long arms getting under the engine refitting the sump pan.

- Big End Cap bolts torqued to 45Nm

What I have done is relatively easy. Just a little time consuming, but fortunately I didn't need a rebore.

Thanks everyone for your help