The V8 Owners Forum -

I am fitting small journal Chevy rods to rover pistons, which obviously have different wrist pin diameters. I have searched through a lot of the threads on here with lots of detail about teflon buttons, having circlips fitted, etc...

I don't think circlips will work for me. There isn't a lot of material in the piston for that. I don't think buttons are going to work either because the insides of my wrist pins are tapered, and not very tidily either, so I won't be able to have nice fitting buttons made (unless I can find a new set of pins.)

So the only solution I can think of is to press fit an insert into the rod that will hold the pin in firm, instead of floating. I'm a bit wary about doing that though.

What do people think?

Are you using the rover pin and bushing the rod to size? if so i would think it would be difficult to have the pin as press fit.

Kevin.

Yes, using rover pin.

I have to ask why the change to chevy rods and retain the relatively weak rover piston, are you changing the stroke as well?

You could swap the pistons for Keith Black Hypereutectic Chevy 305 items and bore the block to 3.736" + required clearance. presumably your using a 3.9 block as a base.

My engine is 3.9 bored to 3.736" 4.2 77mm.crank 5.85" chevy type rods machined to fit rover crank which gives 4.35L and retains revability.

Paul at V8 tuner does the modified rods which use standard Rover size shells, if you buy chevy rods they will need machining to narrow the width and require custom shells.

Kevin.

I'm not using standard rover pistons; I'm not sure what brand they are, but they are the same pin and height. It is a 3.9.

Ive emailed v8 tuner about his rods, and still awaiting a reply. I've already had my block bored for these pistons, and they were expensive so don't really want to swap them.

Well unless you are changing stroke and need a different length rod, then I would just use the 3.9 rods as they should be perfectly adequate for all but full race use.

Paul responds better to a phone call.

Just checked and those 5.85" rods will not work with the pin height of the rover piston and would put the piston approx 150thou. out of the top of the bores, standard rover rods for 3.9 are 5.66" centre to centre.

Kevin.

305 chevy stock bore pistons with a 6" chevy rod, zero deck on a 3.9, gives around 4 litres total. Stress free and apart from modding the rods all off the shelf parts.

Alan

Chevy 305 bore is 3,736". is it possible to bore the Rover cylinders to that size, given that liners would not have too much materia left ? Anyone with practical experience ?

minorv8 wrote:Chevy 305 bore is 3,736". is it possible to bore the Rover cylinders to that size, given that liners would not have too much materia left ? Anyone with practical experience ?

I spoke to Ian Richardson at Wildcat before I did mine and he said a 1mm. overbore was the limit so using the chevy piston is ok, bear in mind that you are only taking off just under 19 thou. from the thickness of the liner.

Kevin.

FWIW you can thin the chevy rods with chevy shells installed and then machine a champher on the shells. This may be cheaper then buying 'special' shells?

How much do the SBC shells need narrowing ? I think Clevite does both std width and narrowed shells but are these too wide ?

Narrow them the same as the rods and then do the champhering so they don't foul the crank. I can't remember the actual width, sorry.

Thanks for the replies.

If I can't make the pin push fit then it's standard rods for me.

ppyvabw wrote:Thanks for the replies.

If I can't make the pin push fit then it's standard rods for me.

If those new pistons are not exactly the same weight as the original ones then you will have to have a full rebalance.

Kevin.