14 replies to this topic

[joecowan]

has anyone used these before,

http://www.ebay.co.u...=item416ab888e9

[TopCatCustom]

Look nice, I'd post the question on the turbo minis forum, you'd probably get a very quick answer with this type of question!

[Artful Dodger]

If the picture is correct then they are for floating small ends, most normal mini pistons a are a press fit.

But you never can tell how good they are unless you use them or get a full engineers report done on them:)

[Cooperman]

They do look as though they are very strong ans fairly light. However, standard A+ rods are good at up the 8000 rpm so long as they are polished, balanced and NDT'd, so unless you are planning an engine which will be regularly revved to well over 8000 rpm they are just a luxury item really.

[joecowan]

im planning on turboing it. i jus havnt got round to joining the turbo mini forum yet.

[Tahiti Joe]

Look nice, however SC ones are only 50 odd quid more.... Forged vs Billet?

http://www.twinkam.c...=6&aid=SC064.A

[TopCatCustom]

Forged any day. When have you ever used a billet spanner (if you have how long has it lasted!) For anything machined from a billet, the material used for forging would have to be really crappy to be worse.

[Tahiti Joe]

Forged any day. When have you ever used a billet spanner (if you have how long has it lasted!) For anything machined from a billet, the material used for forging would have to be really crappy to be worse.

Makes sense, also makes me wonder how the 900 squids Arrow rods are so popular if that's the case...

[Cooperman]

That is why the best crankshafts for a Mini are the original EN40b forged cranks rather than the 'billet-steel' ones currently available new.
Get a nitrided 'S' crank and, in a high-revving engine, change the bearing shells fairly often and the crank will last forever.

[eden7842]

Standard rods are fine spend your money elsewhere

[Cooperman]

Standard A+ rods are fine for up to about 9000 rpm so long as they are lightened, polished, balanced and non-destructive-tested.
Cooper 'S' rods and Innocenti 1275 rods are also good.
The poor rods are the pre-A+ rods with the big 'lump' on the big-end caps.

[Artful Dodger]

i have lightened and balanced my 1275Gt conrods, the poor A seires conrods. is there any possibilitys of breakages or the con rod bending? will be seeing 8000 rpm.

[Cooperman]

Hi Dodger,

With those revs your best bet would be a Cooper 'S' crank and rods in the 1275GT block with special thrust bearings.
The original 1275GT rods are just so heavy and simply machining off the 'lumps' on the caps might well be OK for up to 6500 rpm, but taking them to 8k might be another matter entirely. Can't say they'll bend and/or fail, but can't say they won't. Damned expensive it a rod fails at 8000 rpm. Cheaper to get an 'S' crank & rods.

[Artful Dodger]

hmm its what i was thinking. I got an MED crank that has had alot of work done to it, tuftriding, wedged, balanced and listed as a race crank, so that should be fine. i have gone over the rods quite sufficiently, taken off all of the sharp points and have made all of the edges as radiused as i could.

looking up the cam powerband again it goes up to 7500rpm, so hopefully they should hold. obviously, ARP bolts on them.

may have to limit the revs until i pull the engine apart for the KAD 16valve conversion and then fit a cooper S crank and forged rods:)

Edited by Artful Dodger, 15 October 2012 - 06:01 PM.

[miniobsessed]

Why go to all that trouble when you can use the A+ rods in place of your 'poor' A series rods? They will fit. Just make sure you check the side clearance (at the big end) and if you plan on revving it to 7,500 - 8,000 RPM regularly I would increase the side clearance by a few thou too as the crank does flex and you don't want it grabbing at the rod when it does.