Luke6040
210 posts
Joined: 17/11/2005 17:00:38
Location: Wolverhampton United Kingdom (Excluding channel Islands)
pistons pistons pistons please help
hey
im currently rebuilding an 998 engine im was sure it was post 85 as it has a pre engaged starter but when i stripped it down i found the pistons where the cir clip type with flat tops is this rite?
and where can i get some replacments from as i cant find them anywhere
Thanks for your time
Luke
Posted: Sep 14, 2007 01:27 PM
Mike
18 posts
Joined: 05/07/2006 15:12:12
Location: Johanessburg South Africa
hey dude, look i dunno bout your 998 but i bought myself a '1275' motor once and it turned out to be something different...i gave up trying to find pistons...so i bought myself a crate motor..:)...worked a charm
Posted: Nov 02, 2007 07:42 AM
John
1948 posts
Joined: 28/05/2006 16:49:46
Location: cambridge United Kingdom (Excluding channel Islands)
73.5mm pistons
Anyone know anywhere where they dont cost too much?
Posted: Nov 28, 2007 01:07 PM
998 pistons NEEDED
Hey
I really need a set of 998 pistons for my project. +20 +40 etc would be great id like flat top and cir-clip type unless they're with con rods.
Any help would be great Thanks for your time Luke Lumley
Posted: Dec 04, 2007 06:34 PM
Pistons
Posted: Dec 04, 2007 07:00 PM
J. Lyon
214 posts
Joined: 11/12/2006 18:57:13
Location: Colorado springs United States
I have some +20 pistons that I could pitch your way for a few pounds. They need new rings, but other than that, they're good, maybe clean them off a little too. If you want em, you can have all 4 for 2 pounds a piece, 8? Would have to switch it over to U.S currency, so 16ish plus shipping. Sound fair? Thanks!
James
Posted: Dec 05, 2007 05:37 PM
Roobz
223 posts
Joined: 15/12/2005 01:31:36
Location: Redbridge United Kingdom (Excluding channel Islands)
http://www.minispares.com/Product.aspx?pid=37863
http://www.minispares.com/Product.aspx?pid=38643
Posted: Dec 05, 2007 09:14 PM
That would be so amazing, Just to double check they are flat tops with the circlip fittings or have conrods? How would i go about sortin out getting them? Thank you loads Luke Lumley
Posted: Dec 05, 2007 10:27 PM
They're not flat tops, but they're good on compression. They are circlip type though. I do have the con rods to them, but those I need for my project, they're original cooper s con rods, so I won't have to get race ones. But with what you're saving on pistons, you could afford good ones. As far as shipping, I'll figure out how much it would cost to send it to you, I just need your address, and then I'll let you know what the total is.
-James
Posted: Dec 06, 2007 01:34 AM
On second thouhgt, I think I'm going to go with MED engineering for my engine components, which will include new con rods. So I'd be willing to sell them to you along with the pistons for 20 pound per con rod, so all together, for con rods and pistons with gudgeon pins, all you'd need is new circlips and piston rings, 100 pounds? Let me know if that'll work for you, if not, I can throw in some other parts that I've got if you need them, I certainly don't.
Posted: Dec 06, 2007 02:33 PM
i only need the pistons iv got the rods aslong as ther circlip type all sounds good, if you can give me you email id rather give you my addy over that. I will double chek on here with a few ppl that dished will suit my engine.
Thanks
Posted: Dec 06, 2007 08:16 PM
Hello
I really need some 998 pistons, i have been offerd some, but ther dished how will this affect the engine (good/bad?)
Thanks for any help Luke
Posted: Dec 06, 2007 08:20 PM
it will lower your compression ratio unless u skim you cylinderhead to compensate. low compression will lower the bhp, reduce mpg. advantage is engines start easyier and could run on very low grade petrol as found in some countryies (or tesco on a bad day) lol. ideally u want compression ratio around 9:1 - 10:1 on a standard engine to run on unleaded, higher can be used with premium fuel and higher tuned engine with longer duration cams. 8:1 is minimum you would want to run really. if u pick them i would get ur cylinderhead skimmed to compenstate to some degree at least, 998 heads easily avalible so not something to worry about.
Posted: Dec 06, 2007 11:04 PM
alright, sounds good. My e-mail is jamesgilbertlyon@aol.com
Posted: Dec 07, 2007 12:09 AM
hey,
ther are now some CLASSIC MINI COOPER POWERMAX D TOP PISTONS NOS that iv got my on, what are these will they be better than the original 1985 ones.
Thanks Luke
Posted: Dec 07, 2007 08:03 PM
they wont work with standard A+ head the d will hit the bit of the cylinder head that shrouds the valves on the standard small bore heads. you need a 12g295 or a 12g206 head to use those pistons. also compresion will be too high, on cooper it was around 9.5:1 with 28.3cc head with the standard A+ head at 25.5cc your compression ratio will be around 11:1 or 12:1 something too high for a road engine with a standard duration camshaft. ways to overcome this would be to either buy one of the old cooper head casting's mentioned above or possibly you may be able to enlarge the combustion chamber enouth or skim the pistoms to overcome it but this is by no means certain.
Posted: Dec 08, 2007 12:02 AM
sorry it has been a while but i have been doing some research and i dont think dished pistons will work with set up im building i will just loose too much compression :( sorry.
I will be intouch if i change my mind or hear differant.
Thanks for all of your time Luke
Posted: Dec 10, 2007 06:22 PM
Pistons Again.
Hey.
im buildin a fast road 998 all day everyday mini engine, and im gonna get some new pistons this week i need to bor the engine out so would i be best gettin +20 or +60 i might fit a cooper head, but i cant be sure, so im guessin id get better compression ratio with +20?
Posted: Mar 07, 2008 10:44 PM
you really need to get block cheaked to make sure that first rebore will be enouth, it may reqire 40 min if it badly worn. with cooper 998 if its not skimmed low compression ratio is normally problem as original cooper had raised d pistons so with unskimmed head and flat top pistons you will be looking around 9:1 which will be fine. aim between 9:1 and 10:1 if your using hot cam 10:1 -11:1 should be ok, reboring +20 +40 ect really wont make much diffence to bhp prob half a bhp, this piston design will have more effect, low friction pistons will make more differnce. minispares evo ones look pritty gd. also some blocks will go pourious if u bore them too much as castings wernt always perffect so best start small. also if u bore too much block ragidity and headgasket problems might become an issue.
Posted: Mar 08, 2008 12:00 AM
well i was going to get these first, http://minispares.com/Product.aspx?pid=38643 . but i duno if they will ever be back in stock, i cant get them to mail me back, so it either +20 or +60, unless you got any ideas lol
o just looked and they dont have the +20s now, im startin to hate mini spares lol
Posted: Mar 08, 2008 12:08 AM