standard cosworth rods

[ybp 095]

Hi guys what power (BHP) are the standard rods good for?????

Thanks

[Sunnysidebb]

Hi guys what power (BHP) are the standard rods good for?????

Thanks

Well I have run a 7.2 CR Mountune engine with MT1 & MT1M cams Rs 500 plenum and injectors, Mahle pistons , WRC head gasget, MTD head, 500 IC etc etc @ 2.4 bar on a T4 Turbo and they lasted no problems.
I dont know what the BHP was but I recon it was more than 450.
Frank

[Mark King]

I think there ok until about 400/500bhp

[SCS j1mbo]

600 if you want but the rod angle with them isn't great so wouldn't be a high reving engine, 600bhp and 7000revs they would be ok, but we go for a longer rod with any of the big engines as the rod angle is greatly improved and the piston will not be pushed onto the side of the bore as much!

[B13 JUS]

600 if you want but the rod angle with them isn't great so wouldn't be a high reving engine, 600bhp and 7000revs they would be ok, but we go for a longer rod with any of the big engines as the rod angle is greatly improved and the piston will not be pushed onto the side of the bore as much!

when you do this does that make a shorter stroke, so the pistons move up and down less?

[ybp 095]

So up to 600 bhp the standard rods are ok.

[cosmo]

when you do this does that make a shorter stroke, so the pistons move up and down less?

Rod length has no effect on the stroke fella.

Stroke is determined by the crank.

Longer rod will give a shallower rod angle,

so there is less force acting on the side of the piston and bore.

[Nash]

When using a longer rod you will use pistons to match, not the standard items.

[B13 JUS]

When using a longer rod you will use pistons to match, not the standard items.

ah.. i was thinking you have to match the crank to the rods. so you would a shorter stroke to compensate for the longer rod.

so could you use longer rods with a standard yb crank if you had pistons to suit?
how much would the crank, rods and pistons be out of say wennys new engine?

[Nash]

Your best off asking Jimbo/Harvey or Mark on this mate, they are the experts on this as its what they make there living from.

I know you can run longer rods with pistons to suit on a standard crank, which will give a better rod angle ratio i belive. Then it gets into different stroke cranks with special rods and pistons to suit. I only know what i have read or had explained to me in idiot terms.

[SCS j1mbo]

Wenny is on STD crank and around £1300-1400 iirc for rods and pistons

And yes when you use a longer rod you move the gudgeon pin up in the piston, with a mint untaxed 200 block you can squeeze a 141mm long rod in which is 11 or 12 mm longer that STD iirc!

This works out to give a 1.83 rod ratio over the standard 1.67 if I have worked that out correctly!

[B13 JUS]

Your best off asking Jimbo/Harvey or Mark on this mate, they are the experts on this as its what they make there living from.

I know you can run longer rods with pistons to suit on a standard crank, which will give a better rod angle ratio i belive. Then it gets into different stroke cranks with special rods and pistons to suit. I only know what i have read or had explained to me in idiot terms.

cheers for the info mate

[mark shead]

Hi guys what power (BHP) are the standard rods good for?????

Thanks

For me much above 500hp I would recomend changing due to the age of the rods and being close to the limit.

Mark

[neverenough]

I snapped a standard 1 at 400bhp on my original 70k engine. Meant a new block, rods & crank etc.

[SCS j1mbo]

That's super bad luck! As Mark says we don't use them much over 520/30 but they have done close to 600 iirc porkies old engine had them close to 600 in his track 3door