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Stronger rods for my 4.6 ? Advice please :)

Posted: Sun Aug 12, 2012 7:28 pm
by mgbv8
What are my options chaps.

I think I've reached the safe operating limit of my stock 4.6 rods, so I now want to plan the next build.

I guess there may be some American options as well eh??

Cheers
Perry

Posted: Sun Aug 12, 2012 8:55 pm
by ChrisJC
Have you broke a rod then?

Chris.

Posted: Mon Aug 13, 2012 4:58 am
by minorv8
AFAIK there are no real alternative unless you either order specially made ones or machine existing ones. Rover 4,6 has a rather weird big end size at 2,185" or something. Small block Chevy would be the best option with old big end size at 2" and later engines with 2,1". In either case you´d have to machine the crank to either pin size. Then the SBC rod needs to be narrowed to 4,6 rod dimension.

Again, piston pin size is different, 0,9272 for SBC and 0,940" for Rover 4,6. Either matching pistons or more machining.

There are almost unlimited coice of rods especially in for 2,1" pin and they are reasonably priced. Add some machining costs and special rods may be simpler option.

I am having a favorite shop narrow SBC (Crower Sportsman 6 inch) rods to fit my stroker crank which happens to have big end size of TVR 500 rod. So if that works, 4,6 is a piece of cake.

Posted: Mon Aug 13, 2012 6:31 am
by mgbv8
ChrisJC wrote:Have you broke a rod then?

Chris.

Yes mate!!

Posted: Mon Aug 13, 2012 6:31 am
by mgbv8
minorv8 wrote:AFAIK there are no real alternative unless you either order specially made ones or machine existing ones. Rover 4,6 has a rather weird big end size at 2,185" or something. Small block Chevy would be the best option with old big end size at 2" and later engines with 2,1". In either case you´d have to machine the crank to either pin size. Then the SBC rod needs to be narrowed to 4,6 rod dimension.

Again, piston pin size is different, 0,9272 for SBC and 0,940" for Rover 4,6. Either matching pistons or more machining.

There are almost unlimited coice of rods especially in for 2,1" pin and they are reasonably priced. Add some machining costs and special rods may be simpler option.

I am having a favorite shop narrow SBC (Crower Sportsman 6 inch) rods to fit my stroker crank which happens to have big end size of TVR 500 rod. So if that works, 4,6 is a piece of cake.
Sounds like a plan :)
Keep us posted...
Perry

Posted: Mon Aug 13, 2012 8:29 am
by ian.stewart
Ideal oppotunity to have the crank offset, depending on what rod size, but SBC or BBC will give you a huge choice in cheap rods, but then screws you tith the unavailability of pistons in the right bore size,
Thinking outside the box again, Remember those pistons I had, oversize Ford Modular pistons, I was using 4.0 rods to bring them up the bore for compression, I cant remember what the compression was with 4.6 rods, but it was quite a bit lower, have you spoken to JE about uprated factory rods??

Posted: Mon Aug 13, 2012 8:38 am
by minorv8
My combo uses Real Steel forged stroker pistons. These are for 3.72" bore and have SBC pin size. With 91 mm stroke and 6 inch rod they are pretty much spot. To my big surprise this crank/rod package rotates within a 4,6 block without problems. No clearance grinding required. No contact with cam either. Now if the rod machining is successful ... :D

BTW, these pistons are "ICON" brand.

Posted: Mon Aug 13, 2012 8:39 am
by mgbv8
ian.stewart wrote:Ideal oppotunity to have the crank offset, depending on what rod size, but SBC or BBC will give you a huge choice in cheap rods, but then screws you tith the unavailability of pistons in the right bore size,
Thinking outside the box again, Remember those pistons I had, oversize Ford Modular pistons, I was using 4.0 rods to bring them up the bore for compression, I cant remember what the compression was with 4.6 rods, but it was quite a bit lower, have you spoken to JE about uprated factory rods??
I didnt know they existed Ian ??
I'll give him a shout today..
Pel

Posted: Mon Aug 13, 2012 9:32 am
by mgbv8
thats a good thought Tom. The Cryo treament does seem to work..

I'll have to take the rods off and weigh them as its only about £10 per kilo.

Posted: Mon Aug 13, 2012 10:15 am
by topcatcustom
I'm sure if you polish the rods and have them cryo treated they would last longer, plus be a touch lighter by the polishing work.

Posted: Mon Aug 13, 2012 8:19 pm
by ChrisJC
mgbv8 wrote:
ChrisJC wrote:Have you broke a rod then?

Chris.

Yes mate!!
Cool!, got any pictures?

Chris.

Posted: Mon Aug 13, 2012 8:44 pm
by mgbv8
ChrisJC wrote:
mgbv8 wrote:
ChrisJC wrote:Have you broke a rod then?

Chris.

Yes mate!!
Cool!, got any pictures?

Chris.
I'll have the sump off by next weekend mate. Then I'll have all the gory details in glorious HD photo's :)

I was going to have the sump off tonight but it rained and then I found some beers in the fridge ???

So now I'm typing and watching one of my fave films. "The Worlds Fastest Indian" ... A must see film for all speed freaks :)

Posted: Mon Aug 13, 2012 8:56 pm
by stevieturbo
What are the dimensions of the 4.6 rod ?

Posted: Mon Aug 13, 2012 8:59 pm
by SimpleSimon
mgbv8 wrote:
ChrisJC wrote:
mgbv8 wrote:
Yes mate!!
Cool!, got any pictures?

Chris.
I'll have the sump off by next weekend mate. Then I'll have all the gory details in glorious HD photo's :)

I was going to have the sump off tonight but it rained and then I found some beers in the fridge ???

So now I'm typing and watching one of my fave films. "The Worlds Fastest Indian" ... A must see film for all speed freaks :)
Good call 8-)

Posted: Tue Aug 14, 2012 5:34 am
by Ian Anderson
Time to fit a Chebby?

Ian