Piston Options for tuned Spitfire 1300

[mikeyb]

At long last my balanced crank and rotating parts have come back from Maynards.  I'm thinking of fitting new pistons rather than re-use the old, what are the best options?

I've heard that county pistons are a bit on the heavy side and that the county rings are not too good?

I've also come accross some Covmo pistons too - never heard of them - has anyone else?

Cheers

Mike

[heraldcoupe]

County have historically supplied rings by Grants and Deves, both reputable brands as far as I am aware.
Their piston sets have been extremely well matched in weight when I've handled them, though I have no recollection of what the actual weights have been.

Those most vocal in criticising County pistons have been actively marketing a competing product. That taints any opinion they express to my way of thinking,

Cheers,
Bill.

[Nick Jones]

I've not heard anything bad about County pistons.  The opposite in fact and, as Bill says, they come with decent rings too.

I seem to remember that the racing boys used to use VW/Audi 1300 pistons (made by Mahle I think) but that involved changing the little end bush size and possibly and in between bore size.

County will likely be fine.

Nick

[Deleted User]

heraldcoupe wrote:

Those most vocal in criticising County pistons have been actively marketing a competing product. That taints any opinion they express to my way of thinking,

Came across his ragging on a German site this afternoon about ze pistons - small world!

[mikeyb]

I seem to recall somewhere a discussion on using TR6 pistons, is this viable?  I presume the original spec would have been Hepolite?

[mikeyb]

spotted a bit on Paul Tegler's webpages that praised the county pistons - they actually weighed in some 20g lighter than the originals, are were fairly evenly matched for weight.  Strangely though the gudgeon pins  weighed in heavier.

[Richard B]

3708 wrote:

Came across his ragging on a German site this afternoon about ze pistons - small world!

Can you post a link to it please?   :-/

[Deleted User]

Raging about cams…

http://www.tr-freun.de/modules.php?name=Forums&file=viewtopic&t=7987&postdays=0&postorder=asc&start=15


Raging about pistions…

http://www.tr-freun.de/modules.php?name=Forums&file=viewtopic&t=6052&highlight=county

[sparky_spit]

MikeyB - I managed to find some NOS Hepolite 1500 ones (in the +40 size that I needed) on eBay. I've also got a new set of standard sized 1300 County pistons that I bought some years back at a bargain price, in case I ever needed them. Although there's nothing wrong with the County pistons I have, handling them alongside the Hepolite ones, the Hepolite ones just feel and look nicer and better finished, with less sharp edges, etc.

I know this makes bugger-all difference once they're in there, bedded in and covered in carbon, but I still feel the Hepolites are worth searching out if you are lucky or can wait. Mine came from an eBay seller in Eire.

[That Man]

mikeyb wrote:

I seem to recall somewhere a discussion on using TR6 pistons, is this viable?  

In a 1500 with a block skim, yes

Gordon

[Gt6s]

That_Man wrote:

In a 1500 with a block skim, yes

Gordon

A substancial skim as far as I recall.

[mikeyb]

Been looking up info on the Covmo pistons I had came accross - found an email address for the company and got in contact as below.  It would seem the ones I found were old rather than current!

Hi


    Hello

    I have recently come accross some Covmo branded Triumph Spitfire pistons on the web. I would like to know if this is something that    you manufacture and supply today?

    Many thanks

    Mike

     We can manufacture any of our pistons again; we need a samples to be sent back to us, and an order for   300 pcs or more.  Sample is required to re-assess the metallurgical composition of the material   from which our first pistons were made, and compare that to the present day's changes/improvements in the material

Regards
Darren

[Sheepy]

Hi mike,
I just googled spitfire 1300 pistons (as I'm rebuilding a 1300 engine) and came accross your thread.
It's a few years old now, so may I ask what you ended up doing??  :)

Thanks a lot
Shaun

[thescrapman]

4058 wrote:

It's a few years old now, so may I ask what you ended up doing??  :)

He ended up having another baby.

Try again in 15 years time... :-)

[Sheepy]

thescrapman wrote:

He ended up having another baby.

Try again in 15 years time... :-)

;D ;D ;D

It's now gathering dust then! Wish him pleasure with the baby!

[mikeyb]

Oi cheeky sod   ;D

To be fair, the engine is still gathering dust whilst I collect various random parts to rebuild at leisure. I have some good bits, including a GT tubular manifold and a pair of fuel injection manifolds!  However this level of development is some time away as I need to get the bottom end built up first. My biggest hurdle is space to work, as the garages are a real mess and the clear up is still ongoing!

This week on Ebay I spotted a set of new Hepolites for £90 and nearly bought them, however having previously read up on the subject and taken advice from others, I will be buying County brand as the pistons and rings seem to be ok. As they are pretty much the same price at least I will know I am getting a new set!

Expect to see some progress on this front this year as I have several other engines that need work and will not start another until I have finished the first. Completing the Herald engine will also clear a large space in the corner of the garage which will help facilitate further re-shuffle and clear up!

How's your Mk1 PI engine rebuild getting on Colin?   :B  :-)

[thescrapman]

MikeyB wrote:

How's your Mk1 PI engine rebuild getting on Colin?   :B  :-)

At least I haven't been thinking about what pistins to use for over 2 years!

I have deliberatly not started it until the engine is replaced in the spitfire (an engine you could have had, ready to fit after a coat of paint... :-) )

And the new garage is built.

:-)

Shaun

I can't remember if it is mentioned in those previous threads, but there are some low compression pistins about that are supposed to be very good quality (just need a head skim or block deck)

I also seem to remember reading (and await confirmation) that the rings fitted to the county pistons are not as good as the separate ring sets available from County.

Cheers

Colin

[Richard_M]

As the title of this thread mentioned 'tuned' alongside 'Spitfire' I'll mention the benefits of using GT6 pistons in an over bored Spit engine - the gudgeon pin is almost central which increases available torque with a pay-off of increased piston slap when cold. But if you're after performance….

I'm in the middle of a build just now using County Standard GT6 pistons in a 1296 engine over bored to +40.

R

[Tim Bancroft]

Did'nt there used to be a school of thought that Mini Cooper S pistons were of the right sizes and because of the limitless amount of A serie s tuning parts, there are some fairly exotic pistons to be used?

Am I dreaming this? Was back in the late 80s?

[mikeyb]

thescrapman wrote:

I have deliberatly not started it until the engine is replaced in the spitfire (an engine you could have had, ready to fit after a coat of paint... :-) )

And the new garage is built.

so that could also be a while then :-)

thescrapman wrote:

I can't remember if it is mentioned in those previous threads, but there are some low compression pistins about that are supposed to be very good quality (just need a head skim or block deck)

Thought they were useful for 1500 engines rather than 1300 - we need Mr Banks to remind us.

thescrapman wrote:

I also seem to remember reading (and await confirmation) that the rings fitted to the county pistons are not as good as the separate ring sets available from County.

not heard that one before - would be interesting to have some clarification

[Tim Bancroft]

Ah, all is good in the world, Mike and Colin are bickering!

[Sheepy]

Oops what have I started!  ;D ;D

[thebrookster]

MikeyB wrote:

Thought they were useful for 1500 engines rather than 1300 - we need Mr Banks to remind us.

Yup, the low compression pistons were for the 1500 engine.

Basically they allow you to get away with running a 1300 head on a 1500 bottom end, which would normally cause immensely high CR's. Using the US low compression pistons alleviated this. (I still have a well matched NOS set in my cellar awaiting use, along with a NOS block. Must get on with that project again sometime.................)

[sparky_spit]

thebrookster wrote:

Yup, the low compression pistons were for the 1500 engine.

Basically they allow you to get away with running a 1300 head on a 1500 bottom end, which would normally cause immensely high CR's. Using the US low compression pistons alleviated this. (I still have a well matched NOS set in my cellar awaiting use, along with a NOS block. Must get on with that project again sometime.................)

I agree, to a degree.....  My 1500 engine (which, incidentally is taking just as long to build than either Mike's or Colin's - is it an Essex thing?) has normal high compression pistons with a 1300 Dolly big-valve head. This gives you 9.6:1 compression ratio (if I remember rightly), so it's not that excessive, but you do need to be careful with ignition timing and fuel octane rating.

[JensH]

Bought county pistons for my FD engine rebuild (+20) two years ago. Less than 1/2 gram between pistons - but as mr. Sparky above wrote: not as nice finish (sharp edges etc) as the Mahle standard size pistons, they were going to replace (block needed a rebore).

Free from memory, county ones were aprox 20g lighter than the Mahle ones.

Rings supplied with the pistons didn't come with info of brand; they were this black material (like cast!) - and was within spec.

Engine has aprox 15K (km - I am located in Copenhagen!) on the odometer, and has been well used... No problem so far.