Full set of SIII pistons

[Andrew]

I am not sure what is available but I need a full set of SIII pistons.
Std. size "D" 3.2100/3.2104in (81.534/81.544mm).

Will also require wrist pins and rings

Thanks,
Andrew

 

[RootesRacer]

Replacement pistons are not sold by grade.
This is something that rootes themselves did in order to scrap fewer parts due to marginal machining accuracy.

What you can do is a get a new set of std pistons and have them knurled, which will tighten the clearances in the bores (only reason is to quiet piston slap on worn bores or pistons).

Your first problem will be that 1592 pistons have been unavailable for some time, you have to use 1725 pistons if you cant find 1592 which will result in lower compression ratio due to 1725 pistons having a larger dish.

Your second problem is there has never been a market for STD replacement pistons, so you will probably have to look for factory NOS parts on this one, or a darn good used set.

 

[Alpine Addict]

Alpine West Midlands in the UK lists 1600 pistons. Not sure what sizes.

You may also want to try Speedy Spares in the UK

 

[alpine_64]

Speedy spares would be worth trying.. i have seen quite a few sets of rootes NOS std size pistons in ebay UK.. as Jarrid said not much demand.. so they tend not to sell. Hunt round there in the next few months if you are not in a rush

 

[SIVAllan]

A couple notes/observations .. ??

Places like Venolia make pistons - probably expensive but they build to suit .. ??

How to tell if the factory pistons in the engine are re-usable .. ??

 

[RootesRacer]

Places like Venolia make pistons - probably expensive but they build to suit .. ??

Yes they do, others are J&E, wiseco, Jahns and CP.

All are very expensive unless you get a "jobber" to order you a set.
The bigger issue is that none of those folks are going to engineer a piston for you. You either know exactly what you need to know to order the pistons, or its going to be a short call with them on the phone.

How to tell if the factory pistons in the engine are re-usable .. ??

You look at the surface condition, make sure it hasnt eaten some of its own ring bits or other material.

You inspect the and measure the sides of the pistons where the wear is and make a determination of the pistons are too worn.

Lastly and probably most importantly, you measure the ring clearance in the ring lands, too much clearance and the rings will get hung up and break.

The bores of the block tend to wear much more than the pistons, so if the ring lands are OK and you arent put off by the wear of the bores, then the pistons are probably re-usable.

 

[SIVAllan]

Thanks, that is quite helpful !!

By ringlands, I assume you mean the 'groove' with concern for wear not being the depth, but the up/down wear on the piston due to the rings moving up as the piston changes to down, and vice versa .. ??

But how much is too much. A centimeter ??

As expensive (and sometimes scarce) as the Alpine pistons can be, it would be helpful to lots of folks I'd imagine (including me ) .

When I built an engine before (decades ago) we had not heard of this problem, and just reused all the ones that were not cracked .

I'd think that non-abrasive techniques like ultrasound could clean up used pistons nicely -- if they are decent enough to re-use.

 

[Andrew]

What have I done?

1725 pistons if you cant find 1592 which will result in lower compression ratio due to 1725 pistons having a larger dish.

Lower compression, I can only assume that would result in less power.
I guess what should be done is to measure the ring lands and see how much extra space there is.

I have held off on using the ball hone as I have no idea what direction I should be going in.

If I install new std. 1725 pistons and rings is there anything that should be doing to the block? Are the 1725 pistons the same size in diam as the 1592?

I have posted some new images of the clean pistons and my new timing cover mod but I am starting to think that I am a little over my head.

I guess I could ball hone the cylinders and then take some measurements to see what I am in for. I will also measure the ring lands at the same time keeping some tissues on hand.

Thanks for your help guys.....at time I wish that I wasn't up here in the great white north and that I was a little closer to you Rootes Gods!
It would also be nice to work outside in the sun but the 4' snowdrifts and closed roads are a bit of a deterrent.

My new pictures are posted on the same site:
http://www.ramdesign.on.ca/sunbeams/rebuilding.htm

Andrew

 

[Jim E]

Imagine it would be hard to find someone who can knurl a set of pistons in this day and age.

You might want to also watch for a set of the 1500 flat top pistons on ebay uk those should be cheap in std bore.

 

[RootesRacer]

Lower compression, I can only assume that would result in less power.
I guess what should be done is to measure the ring lands and see how much extra space there is.

I have held off on using the ball hone as I have no idea what direction I should be going in.

If I install new std. 1725 pistons and rings is there anything that should be doing to the block? Are the 1725 pistons the same size in diam as the 1592?

I have posted some new images of the clean pistons and my new timing cover mod but I am starting to think that I am a little over my head.

I guess I could ball hone the cylinders and then take some measurements to see what I am in for. I will also measure the ring lands at the same time keeping some tissues on hand.

Thanks for your help guys.....at time I wish that I wasn't up here in the great white north and that I was a little closer to you Rootes Gods!
It would also be nice to work outside in the sun but the 4' snowdrifts and closed roads are a bit of a deterrent.

My new pictures are posted on the same site:
http://www.ramdesign.on.ca/sunbeams/rebuilding.htm

Andrew

Yes putting in 1725 pistons in the 1592 will reduce compression, IIRC you go from 9.2 to 8.5.

This doesnt put many people off though, its been done for years due the unavailability.

The 1725 is dimensionally identical to the 1592 minus the depth of the dish.

If you mill the head, you will recover some of the lost compression, measuring the depth of your wear beard under the head will allow you to guess on how far its already been milled.

There is nothing you can do to the chambers to gain back compression, if you remove material like in the vizard or holbay mods, you will loose even more compression.

 

[jumpinjan]

I feel lucky there's vendors still around that still sell new piston sets.

 

[Bill Blue]

Andrew, your starting down the slippery slope. Keep in mind the original purpose of the teardown.

You found enough strange stuff to explain the situation, correct? You've cleaned the pistons, in general, they look okay. Do they all have the same wear and tear? If so, buy a set of standard rings, ball hone the block (rotation direction should not matter, but go clockwise if possible) and reassemble.

Start saving money for the "dream" engine and have fun driving. Keep in mind, when you do the complete rebuild, you will rebore the engine and need oversize pistons. No point is spending that money twice.

From a practical standpoint, you have two choices: New rings, slap it together and drive, or complete rebuild.

Bill

 

[Andrew]

Andrew, your starting down the slippery slope. Keep in mind the original purpose of the teardown.

You found enough strange stuff to explain the situation, correct? You've cleaned the pistons, in general, they look okay. Do they all have the same wear and tear? If so, buy a set of standard rings, ball hone the block (rotation direction should not matter, but go clockwise if possible) and reassemble.

Start saving money for the "dream" engine and have fun driving. Keep in mind, when you do the complete rebuild, you will rebore the engine and need oversize pistons. No point is spending that money twice.

From a practical standpoint, you have two choices: New rings, slap it together and drive, or complete rebuild.

Bill

I hear you Bill and Jim,
I will ball hone and keep things clean, install new rings and button her all back together and get her ready for a fun summer. I will then look for another engine to rebuild and do it right.
Thanks again guys, when I get her back together I will post photos.

Andrew

 

[Jim E]

It will be fine, you will have blow by like a train but who cares for a couple hundred bucks you will be rollin!
Your rod bearings look ok but the one water passage on your head looks funky, may just be the picture

 

[skywords]

Here is a link for some Hepolites that are the oringinal manufacturer so I've been told. He wants 100 for a set and lists standard as well as over size. I have two sets on the shelf I paid 150 each for.

http://ottawa.kijiji.ca/c-cars-vehi...-NOS-pistons-rings-in-boxes-W0QQAdIdZ79691025

 

[howard]

If you're looking for old 1592cc pistons, I have some very used pistons you're welcome to. I've NO IDEA if they're in good enough shape for what you're doing. I had them pulled when I had my engine rebuilt this past spring, and I'm no expert, so it may just be a waste of postage. If you want 'em... send me a pm.

 

[Andrew]

Here is a link for some Hepolites that are the oringinal manufacturer so I've been told. He wants 100 for a set and lists standard as well as over size. I have two sets on the shelf I paid 150 each for.

http://ottawa.kijiji.ca/c-cars-vehi...-NOS-pistons-rings-in-boxes-W0QQAdIdZ79691025

Hi Rick,

Very good and they are not all that far from my location, it shouldn't cost much to ship. I will check it out and what size he has for the Sunbeam.
Could anyone use a set if I make a purchase?

Andrew

 

[JonPiz]

If your still looking I saw this on Ebay

http://cgi.ebay.co.uk/Sunbeam-Alpin...14&_trkparms=72:1301|66:4|65:12|39:1|240:1318