Piston Advice

[utey]

Hi.

Have my motor in for a rebuild and was told pistons will have to be made at a cost of $700+
Questions.
Where to get pistons.
If bore to 149 what pistons fit
What alternatives.
Ideas.
I know its silly but want to stick with grey.
As always help greatly appreciated.

Nick

[CraigA]

There's a guy who list grey motor piston/ring sets on eBay.

Here are his details:

Straightline Performance Parts
Po Box 316, St Clair, NSW 2759
p: (02) 9670 6300  f: (02) 9670 2523
http://www.stores.ebay.com.au/straightlineperformanceparts

His name is Mick.

[utey]

Thanks Craig

Contacted Mick $800!
JP in SA  $700+

Nick

[Geoff_K]

Hi, when my mechanic rebuild by grey motor, we increased the bore to suit a common size / standard available piston.
I believe it may have been a metric sized piston and ring set out of a Japanese engine.
My guys used engine borer/reconditioner, who knew a lot about pistons, and they used a set of pistons with a "common sized gudgeon pin", and "equal distance centre line of gudgeon pin to piston crown", of the required bore.
Thus I got a rebored block, new pistons, rings etc., with the bore finishing up at about 31/16"
Price was right, and all I was asking for was a standard rebuild.
Geoff_K

[FC427]

Geoff is right on the money most re conditioners have reconditioning manuals that cover most cars with  bore, stroke, gudgeon pin size ,piston size, crown height piston offset,  etc etc sometimes the little end of the conrod has to be bushed to get the right pin size , sometimes the crown of the piston needs a little machining to get the deck height right and with so many Japanese high performance engines out there the quality is far Superior to anything that GMH ,ACL Repco ever made it's a win on price and a win on quality ....Hear is another example BMW conrods in a red six how many more are there  ......FC427......

[Old_Mt_Isa_Boy]

Anyone know someone (mechanic) in the Brisbane area that we could trust to give us this answer and not the expensive solution. People I speak to think that I'm mad for keeping the grey as well, but I think it's worth it. It just costs more. Suggestions appreciated. Regards Wayne B. 

[weddo]

Hi Utey Nick,
When I built my motor and replaced the pistons with Westlite hitop pistons (both sets +40th) I used mazda 323 rings
I still have the original +40th pistons, rings and gudgeons (would probably need new rings) if you are interested PM me


I have a shed full of good, mosty used parts for motors and some gearbox parts



regards
Weddo

[utey]

Geoff

What pistons were used??
This is could solve a problem that a lot of people are likely to encounter in the future.
Paying 700-800 for a set of pistons is going to lead to a lot greys being thrown out.
Wonder if it would be possible to get consortium of clubs together to investigate pistons made in China!!!
Too hard ??
Any information thoughts on alternative pistons would be great.


Nick

[Dave88]

Hey Nick,

I purchased a 3.25" bore Grey Motor last year and was told that it had Zephyr pistons in it. They're a standard flat top piston.
Sorry I can't tell you what series Zephyr they're from, but it could be worth investigating further. Mk1 and Mk2 would be my first guess.

I'm due to pull the pills out of this motor in the coming months. I'll have a closer look and let you know when the time comes

Dave

[FB_MAD]

  I think this is a great idea if blokes can throw up some of the piston/ring combinations that they have used in grey motors for rebore purposes as it will help others  heaps in trying to find a cheaper alternative to the high cost of buying replacement pistons specifically made for grey motor fitment.

The prices of replacement grey pistons is probably the major contributor to the high cost of grey motor rebuilds.

If a cheaper japanese piston can be fitted for say half the cost of a grey specific piston then I'll fit them both for cost and the fact that the jap piston will most likely be a better piston to use anyway.

Alright fellas, FC 427 has already thrown up the "BMW rods will fit grey" secret as a starter so if any of you other blokes have something to tell cough it up!! .

And getting right back to one of utey's original questions "if I bore to 149 what pistons fit"

  Without me actually sitting down and working out using the formula for cylinder  volume size ( pie X radius squared X stroke) ...... from memory some greys can be bored to 149 but I think 149 ends up being about a 100 thou/120 thou oversize piston or thereabouts so you would have to have the grey blocks bores checked to see if the cylinders have sufficient metal in them to be able to take that much oversize rebore.

[FB_MAD]

Just had a thought,

Here's something a lot of blokes don't know.

A 149 red motor can be bored out to 161 cubic inches as I have one in my car that has genuine GMH 40 thou oversize 161 pistons in it ( which equates to 167 cubic inches ) .

Runs great,have done at least 5000 miles so far in it and it was a used engine when I bought it!!

In NSW 149 can be fitted with no mods required so I basically have  a legal, no mod required, 161 fitted.

[JSM]

There is a site that i've seen when looking for other bits and pieces; http://www.summitracing.com/

They have a pretty cool Catalog set up that allows you to search for pistons amongst other things by their dimensions rather than what they suit. You can specify the bore size etc and search for available pistons.

These are some pistons with bore size 3.071 inches, slightly bigger than a std 138 - http://www.summitracing.com/search/Department/Engines-Components/Part-Type/Pistons/Bore-in/3-071-in/?Ns=Rank|Asc

Does any one know the compression distance of the grey motor pistons std? I'm sure some one here knows enough about std grey motor piston dimensions that they could use this to see if theres something suitable. There would be a limited range that you could vary conrod length (if at all successfully) but there's quite a few feasible bore sizes (i.e. greater than std but smaller than something like 3.25 from a 149) as long as we can find something with a suitable compression distance and pin location / geometry.... as mentioned earlier pin diameter can be compensated for with bushing to some degree...

Hopefully someone who knows more about grey motor pistons than I can have a geez and see if theres anythin feasible... or give me some piston dimensions etc

Cheers
John

[Sheriff]

Have a look at the American Autos site.  They list oversize pistons etc.   try this link.
http://www.americanautos.com.au/h-ek.pdf
then go to engine components - gray motor pistons.   p. 33.  Good luck.  Mike.

[JSM]

Cheers for that Mike!

Thats great! Those prices don't look that expensive at all!....

Cheers
John

[Trevor_B]

You will need to check with American Autos re availability.
They appear to list almost everything they have ever sold on their full internet site https://www.americanautos.com.au/secure.html and and so 3 things can impact you getting what is listed:
1. "in Stock" i.e are they available right now?
2. "on order" i.e have they ordered them from the supplier & so there will be some delay before they are available;
3. Price. If in stock then price is per internet list (+postage if applicable). If the part needs to be ordered in then the price is likely to change. I have had one experience where the price doubled as the listed price related to the last time they sold this part (obviously several years earlier) - they did negotiate on the final price after some discussion. The up side is that if they have old stock then you can get a bargain - for example, the JP Alloy timing gear I bought a few months ago @$236, price from Bursons was$500+

Check this one for example of in Stock/on order: https://www.americanautos.com.au/cgi-bin/fccgi.exe?w3exec=aap.control&session=1498771792314429&formname=prices&newform=product&option=6KRY2075-040

Stories I have heard on pistons recently is that 3 1/16" STD are the only ones you can get. Mahle (ACL) are apparently requiring a min order of 50 sets before manufacturing other sizes (told to me by a reputable supplier so probably right?). Sounds like we need to look for alternate suppliers. Not sure what price JP Pistons are but hear they are expensive by comparison. Anyone have JP Prices/availability??

Trevor_B

[JSM]

Fair enough, I'll have to look into it further... still reckon there would have to be something else that would do the trick.
Did anyone end up having a geez at the summit site? or have some detailed piston dimensions?

Cheers
John

[utey]

Hi

Contacted American Autos they can supply pistons but cost for 3.125 nearly $900.
Summit racing have pistons for a Jeep that are the correct bore but don't know of other dimensions.
Mk1 Ford Consul/Zephyr are the correct bore but no doubt will be just as expensive as I doubt will be a stock item.
Contacted JP about $720 for a set less 15% with ABN (might not be right, was pretty disappointed by then, will check on Monday)
Thanks for the input.
This is a cost that all of us that run Greys are going to have to face sometime in the future.
You would think that Rare Spares would be manufacturing engine parts as there must be hundreds? of Grey motors still running?

Nick

[mcl1959]

Rares purposefully do not do engine components because there are so many suppliers out there

Ken

[FB_MAD]

Have a look here>  http://www.jp.com.au/JPPistons.html  at the JP Pistons website and you should be able to find what they stock and can make although they aren't cheap the last time I enquired.

[pedro]

If you're looking for a really cheap way out of it, when i rebuilt the grey engine i was going to use in my wagon i pulled down two engines, one had a larger bore so i got the engine reconditioner to check to make sure the larger pistons were alright, then he bored the other block to suit, all i had to buy were new rings and gudgeon pins.
                          Pedro