The rebuild of no 219

[Wild E. Coyote]

[post]360556[/post] I've just had a look through all the bits I've bought, the rings I use are indeed NPR :?
I'll see how they go with this engine given it's not the original engine. I get a lot of nitriding done through work, I wonder if I could get the chrome removed and then nitrided. Or I could look at getting the cylinders relined in steel?

The thing with material pairing is that you by design want to make one material softer and one harder to be able to predict the behaviour in advance. Chrome is very hard and so is nikasil so you don't know which one will let go and obviously you don't want the nikasil to let go.
Here you can download the NPR catalogue: http://www.npr-europe.com/index.php?article_id=3&clang=1 and then browse through it. There you will find the finish of the rings and some explanations about them. Since there is no set meant for puma 1.7 engine (factory designation is MHA/MHB) I advise to go and have a look at sets for Porsche 911 from say 1987-2000. Those engines are nikasiled as well as puma engine and have a look at finish of those piston rings to see about the material pairing.

Regarding the sleeving: if you do that, you have removed one big hurdle out of equation: then you can use the honda set without problems as that set is designed for cast iron block and that is what you will efectively have if you resleeve the engine. However, you may have noticed that there is really no space between cylinders and I am affraid the sleeving might warp the engine block.

I would just like to stress one thing out: the rings being NPR means nothing bad, as NPR is very good company and their products are top class (on par with Goetze or Mahle): the problem is that particular set is not designed for puma engine.

Since you are thinking about removng chrome and nitriting of rings, I really do believe it is easier to order that other set for Nissan engine (I gave the cat. number in previous post) and use it's 1st compresion ring as it is already nitrited. The second being phospated in Honda engine is quite OK to be used.
Regarding the 3rd (oil scraper): In Nissan set it is nitrated but the stated height is 2.5 mm and I believe it is somehow to low. It is a 3 piece design so I guess you could use the rings form the Nissan set (again, they are nitrited) and the spring element either from existing puma or from Honda set to bring the rings to desired height.

IMHO that would be much easier and cheaper route than either sleeving or modifying the rings from Honda set (the chromed ones)

 

[Wild E. Coyote]

[post]360552[/post]
And Sinisa, another awesome find with the combination of rings. How'd you work out which ones would work and which ones wouldn't! Amazing attention to detail.

Being an engineer sometimes helps with these things, mate :wink:

 

[richard_rip]

[post]360565[/post]

[post]360556[/post] I've just had a look through all the bits I've bought, the rings I use are indeed NPR :?
I'll see how they go with this engine given it's not the original engine. I get a lot of nitriding done through work, I wonder if I could get the chrome removed and then nitrided. Or I could look at getting the cylinders relined in steel?

The thing with material pairing is that you by design want to make one material softer and one harder to be able to predict the behaviour in advance. Chrome is very hard and so is nikasil so you don't know which one will let go and obviously you don't want the nikasil to let go.
Here you can download the NPR catalogue: http://www.npr-europe.com/index.php?article_id=3&clang=1 and then browse through it. There you will find the finish of the rings and some explanations about them. Since there is no set meant for puma 1.7 engine (factory designation is MHA/MHB) I advise to go and have a look at sets for Porsche 911 from say 1987-2000. Those engines are nikasiled as well as puma engine and have a look at finish of those piston rings to see about the material pairing.

Regarding the sleeving: if you do that, you have removed one big hurdle out of equation: then you can use the honda set without problems as that set is designed for cast iron block and that is what you will efectively have if you resleeve the engine. However, you may have noticed that there is really no space between cylinders and I am affraid the sleeving might warp the engine block.

I would just like to stress one thing out: the rings being NPR means nothing bad, as NPR is very good company and their products are top class (on par with Goetze or Mahle): the problem is that particular set is not designed for puma engine.

Since you are thinking about removng chrome and nitriting of rings, I really do believe it is easier to order that other set for Nissan engine (I gave the cat. number in previous post) and use it's 1st compresion ring as it is already nitrited. The second being phospated in Honda engine is quite OK to be used.
Regarding the 3rd (oil scraper): In Nissan set it is nitrated but the stated height is 2.5 mm and I believe it is somehow to low. It is a 3 piece design so I guess you could use the rings form the Nissan set (again, they are nitrited) and the spring element either from existing puma or from Honda set to bring the rings to desired height.

IMHO that would be much easier and cheaper route than either sleeving or modifying the rings from Honda set (the chromed ones)

Really appreciate the info :grin:
Strength was definitely something that concerns me about sleeving the block, but it could solve other issues, like if the bores have worn a lot of the original engine. That said I have seen that theres a few companies that can re Nikasil the bores, but I'm not sure on the cost.

I'll have a look through that catalogue to see what I can find under the Porsche section. I might also speak to our heat treatment company and see if you can nitride onto of chrome. We get loads of stuff nitrided at work because it doesn't pick up like other heat treatment processes but I've never tried chrome, I've had high chrome tool steel nitrided as well.

As I say I'm not too concerned as that engine will be coming out, I might keep my eye on the compression though

 

[Wild E. Coyote]

TBH, I don't think ANY of engines with nikasil intact have worn!

Regarding the Porsche: be careful to look only at the aluminum engines. 924-944 (4 cylinders are not aluminum).

If you can nitride, than it might be the easiest way to just have piston rings made and then nitrited?

 

[richard_rip]

Silly question, but what are the first rings made from?

 

[richard_rip]

With the block rebuilt it was time to move onto the head.
After a damn good clean and trip though the dishwasher for good measure I wanted to clean and reseat the valves, they were a bit messy.

After a good going over

I then went through all the valves with some lapping paste so they were sitting nicely again, all were blued out to make sure they were sealed. It's amazing how much difference it made, before I lapped them they felt lumpy and rough as you spun then, really smooth afterwards :grin:

You can see the ring left by the lapping paste, nice and even all round

 

[Wild E. Coyote]

[post]360581[/post] Silly question, but what are the first rings made from?

There are no silly questions, only silly answers...

I would think it would be a steel one, as it is a revvy engine and the ring itself is very thin at 1.15-1.20 mm

 

[richard_rip]

[post]360584[/post]

[post]360581[/post] Silly question, but what are the first rings made from?

There are no silly questions, only silly answers...

I would think it would be a steel one, as it is a revvy engine and the ring itself is very thin at 1.15-1.20 mm

Haha
I wonder if I could make some <_<

 

[Wild E. Coyote]

In that case, this could be a good read.... :wink:
https://media.mahle-aftermarket.com/mc/download?lang=en&assetId=72103188

 

[richard_rip]

With the valves reseated it was time to fit the new valve seals and rebuild the head. Once I'd done that I could test the valve clearance, they were all within spec.

Once that was done it was time for some new parts, lots of them. I got in touch with Burton Power to order some bits, other came from a parts supplier near my work, the rest was from eBay.:
Thermostat
Water Pump
Set of head bolts
NGK Platinum spark plugs
Magnecore 8mm blue leads
NGK coil pack
Fai OEM full head gasket set
Gates timing belt kit
Gates drive belt idler
Continental drive belt
Genuine oil pressure switch
Genuine crank sensor
Genuine crank case seal
Under the advice of the RPOC Facebook page I decided to order an ST150 Valeo clutch with a new Sachs slave cylinder to fit the Puma

Once everything had arrived on a cold January night the head was bolt to block :grin:

Just before I pulled the pin to tension the belt

 

[g-whizz]

Nice going Rich....And loooks like you've got a well stocked garage there to get the job done :wink:

 

[Wild E. Coyote]

Very nice! How are you going to prime the oil pump? By just cranking the engine?

 

[richard_rip]

[post]360591[/post] Nice going Rich....And loooks like you've got a well stocked garage there to get the job done :wink:

I like to keep lots of tools, bikes and beer in my garage. One of the things that's great about this weather is that your rebuild refreshment is chilled lol

 

[richard_rip]

[post]360593[/post] Very nice! How are you going to prime the oil pump? By just cranking the engine?

Yes I just popped the plugs out and spun the engine manually once it was hanging back in the car :grin:

 

[red]

great work, very inspiring!

 

[Wild E. Coyote]

[post]360545[/post]
With the new rings in and cleaned. All the rings were gapped to ford spec for each cylinder and were ready to go back in the block

How did you manage to clean the piston so well?!? I am trying and can't get near that state. Tried brake cleaner, some nasty stuff that melts rubber gloves in 5 minutes, using also used toothbrush....

This is immaculate

 

[richard_rip]

[post]360751[/post]

[post]360545[/post]
With the new rings in and cleaned. All the rings were gapped to ford spec for each cylinder and were ready to go back in the block

How did you manage to clean the piston so well?!? I am trying and can't get near that state. Tried brake cleaner, some nasty stuff that melts rubber gloves in 5 minutes, using also used toothbrush....

This is immaculate

Oven cleaner mate, to be more specific Ovenpride. I had a big tub of warm water in front of me, dipped a toothbrush in the oven pride and scrubbed. Worked really well :grin:

 

[Wild E. Coyote]

Indeed it did! Ok, will try that as well. It never occured to me although, to the complete irony, I am the one telling people not to underestimate the power of kitche cleaning products as that are the best degreasers available and surviveable at the same time.....

 

[richard_rip]

Fully rebuilt and ready to go back in the car, the only "issue" I have is with the ignition leads. The length of some on the leads isn't quite right and they don't sit very neatly, I've tidied it up since taking this pic but it still isn't as good as it could be. I've used Magnecor leads on two previous cars and they've been great so thought I'd use them on the FRP.

 

[richard_rip]

[post]360767[/post] Indeed it did! Ok, will try that as well. It never occured to me although, to the complete irony, I am the one telling people not to underestimate the power of kitche cleaning products as that are the best degreasers available and surviveable at the same time.....

Very true, Fairy liquid is an awesome degreaser haha
Quite a few people suggested brake cleaner/wheel cleaners but they didn't do much for me