20773 with a 998 users
Turbo Mini Forums

Afternoon lads

Right ive hit a snag with regards to het my block etc done, straight to the point .....

I bought 20773 +020 to go in my block, planned on using standard rods but turns out the rods in there
Are press fitted while the 20773's are floating pin/circlip.

My options are get rods that take the floating piston or
Get pistons which need to be press fitted.

For the guys which have run this set up, what rods are you using please ?

Cheers

I use the earlier bushed A+ rods for ease of assembly/disassembly, but you can just use the press fit rods with the 20773s.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

The problem i got paul is the conrods are the wrong ones ( so the machine guy told me )
He reckons the rods that came out can be ( have a press fitted flat top on them ) cant be used with the 20773's due to them being a floating pin, also the rods are a 45 degree angle at the bottom, apparently the ones i need are 90.

Does that sound right ?

That's all bollocks.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Now im confused lol

So is your machine guy.

If something is worth doing, it's worth doing half of.

Mmmm somethings not right, so the hole would be the same size for both pins then ? He was mentioning something about rods with the bushes.

Think ill try and get one of the pins out later on.

Yes i moved to the darkside

Instagram @jdm_brett

These are what hes telling me to get ( found from one of sprockets post ) but machining the other ones is a good idea.

Edited by Scudy23 on 9th Nov, 2012.

your machinist is an Arsehat....

I thought you could ream out A+ rods to go full floating

i was told that you just use the pin that caomes with the pistons and either press them in the rods if press fit and discard the clips or if you use floating rods use the clips. It tells you that on mini spares site too. But as chalkie says you can have the little end reamed/honed out to make the pin floating

My small bore turbo project http://www.turbominis.co.uk/forums/index.php?p=vt&tid=473901

Nice one guys will be onto him monday, this is the first time ive ever needed to use a machinist for anything but think ill have to look around.

Right

998 rods are diagonally split on the big end, 1275 rods are horizontally split.

All 1275 rods are interference fit little end. 998 rods come in either pinch bolt, floating or interference fit.

You can install 1275 rods in a 998 but you need floating pins since the rod will not pass through the bore (the big end is too wide) so you have to assemble the pistons onto the rods after passing the rod through the bore from the bottom, but then of course, there are no floating pin 1275 rods as standard, and the remaining fact that the 998 big end journal is smaller than the 1275 big end journal, so it wouldn't work anyway.

You can use the interference pin 998 rods with a floating pin piston, just leave the clips out of the pistons, or, you could source a set of floating pin 998 rods, and yes, they did a floating pin A+ rod.

Lastly, take your engine somewere else.

Hope thats a bit clearer :)

Edited by Sprocket on 9th Nov, 2012.

Can you fit 1275 rods in a 998? No! Cooper S rods could be adapted to fit a 998 is more correct

Also forgetting that the 1275 little end is larger anyway, they would need bushing down.

All this adds up to suggest your machinist knows less about the A series engine than he makes out.

What the situation with drilling a hole in the little end sprocket ? Read on here that it helps lube the gudgeon pin, would it be a case of just drilling a hole or is there something else toget the oil through there.

no need

what is wrong with the rods you have?

Edited by Sprocket on 9th Nov, 2012.

Going by whats been said i need the little end reamed/honed.

Machininst told me the i needed the floating pin conrods but save the hasstle and ill ask him to make the little ends bigger to accompany the pin on the floating piston.

Dont think theres anything wrong with them as such, said you cant use pressed pin conrods with floating pin pistons and visa versa.

Edited by Scudy23 on 9th Nov, 2012.

Seems a long expensive way around a problem that does not exist.

Use the rods you have and press fit the pins, then discard the clips, job done.

Edited by Sprocket on 9th Nov, 2012.

Would there be any difference in pin thinkness between pressed pin and floating pin pistons.


This must be getting on peoples tits now but i want to go back to the shop with the easiest option, if he dont want to do it then bollox to them.

some machine shops dont like the idea of reaming out the little end without bushing it like earlier rods but it is a tried and tested method now and works fine. It dose sound to me that your guy dosen't really know the a series as well as you would have hoped. Thats not to say his work isn't good but it wouldn't fill me with confidence. Surely there is another shop you can go to.

My small bore turbo project http://www.turbominis.co.uk/forums/index.php?p=vt&tid=473901

The easiest way is as described above. Just assemble what you have. That is press fit the gudgeon pin through the rod.

All 998 gudgeon pins are the same external diameter, the difference is in the little end internal diameter. so everything fits everything.

The only thing you can't do is fit slipper pistons to floating rods. The reason for this is obvious, as the slipper piston has no skirt and a short gudgeon pin with no way of retaining it.

And just to confirm what Sprox said, yes 998 rods come in floating and no-floating varieties.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

Pinch bolt type con rods are very rare for a 998 out all ones I stripped down working for a mini company only come a across 3 sets all in 850 engines.


And if you want to stroke your engine or get different conrods go Swiftune's set
http://www.swiftune.com/Product/757/swiftu...onrods-998.aspx

:] deffo burn a hole in your pocket.