20v Conrods

[radke15_sprinter]

I'm building my blacktop, i got some new forged pistons, but I'm not sure weather the orginal rods will be sufficent,

i plan on running a turbo on the engine. any words of wisdom wll be greatly appricated.

[Rolliac]

Apparently silver top rods are beefier.

 

If you really want to wind the boost up, forged rods would be piece of mind I’d think.

[SLO-030]

The Brand SPOOL comes to mind. PM a member by the name of Greenmac80.

[radke15_sprinter]

yea i have seen them side by side and there is fair bit of difference.

i seen those attkd rods o ebay but i have little faith in ebay sutff.

has any one used them.

[MRMOPARMAN]

silver top rods will do the job. and red top rods are better again. do not be fooled by "gze rods", their exactly the same as regular redtop rods.

 

*properly prepped* red top rods are known to go 25+PSI and 8000rpm in built motors.

 

if your after the best rods, no money spared. go aftermarket, eg argo, crower, spool etc. only for their lightness. if your on a budget, redtop rods are the go.

[greenmac80]

ATTKD rods and products seem to have a good reputation. actualy distributed by AUTECH aus. i think or

is an offshoot of AUTECH they look the goods anyways. but bear in mind for that money you can get SPOOL rods which are a known

high quality brand.

[greenmac80]

ATTKD seem to have been use by some skyline owners succsessfully did some searching on forums.

 

only thing there is another brand on ebay...

maxspeedingrods. i can't seem to find anything on em so i'd stay away from them i reckon.

 

if you want to build the motor to rev much past 8600 rm i'd definately go with forged rods standard rods in any form won't put up with it.

and if they do it won't be for long. also as for boosting it all depends on how much boost and how much compression.

if the compression is like 8:1 and your gonna run 1 bar i would expect standard rods to survive for a long time. if your gonna go with 9:1 or 10:1 i'd definately be

getting forged.

[radke15_sprinter]

thanks greenmac, that exactly answered my question, so i think spool rods will be goin in,

i think the pistons are 10.5 so i wont be running insane boost just enough to get some power.

[Taz_Rx]

Heard rumors spool is about to start making K series forged rods soon too!! :)

[greenmac80]

if u use all arp hardware and forged internals you should be pretty safe with up to 10 psi i would think

and due to the high compression the power figure will be pretty healthy and offf boost you'll still have plenty of response.

 

if your gonna spin it harder than say 8400 you have to shim the oil pump to get enough pressure.

[Sam_Q]

I would think that running any reasonable boost would be fine with blacktop rods, this is because the killer of rods in a 4a engine is revs not compressive load. The reason why this is so is because on the compression stroke the inertial load of the piston and rod counteracts the compressive force. There is some bending force at a reasonable amount of the point of 90 degree on the downstroke. Long story short keep the revs at 8000 and you will be fine, cheap upgrade with silver-top rods that will have a block break before they do or lastly the after-market rods which are better suited to atmo engines in my personal opinion.

Edited November 15, 2009 by Sam_Q

[beerhead]

Sam, just wondering why would you say that the aftermarket rods are better suited to atmo engines?

 

Chrome moly is good stuff, very light for the load it can handle, I would have thought the weight reduction, increased strength and added big end bearing rigidity would make the motor last longer than a motor built with standard rods of any variety.

[SLO-030]

Heard rumors spool is about to start making K series forged rods soon too!! :blush:

 

:P are you cereal?

[flat out]

yeah it is true that spool are making 5k rods allong with

 

Holden 202

 

Suzuki Swift

 

Mitsubishi Magna 3.5 L

 

Holden Commodore V6

 

Toyota 1UZ

 

Toyota 22R

 

Ford 4.0 Lite ( EL - EF )

 

 

i will be getting one of there rebuild kits shortly

[Sam_Q]

Sam, just wondering why would you say that the aftermarket rods are better suited to atmo engines?

 

Chrome moly is good stuff, very light for the load it can handle, I would have thought the weight reduction, increased strength and added big end bearing rigidity would make the motor last longer than a motor built with standard rods of any variety.

 

ok I am guild of generalising and being vauge. I was talking in terms of necessity instead of being an improvement as such. It's very rare for anyone with a boosted 4a engine to have different cams so they often don't rev hard enough to necessitate stronger rods and rod bolts. That combined with the overkill strength of a silvertop rod which can handle any boost. The atmo guys running big cams rely more on revs and responsiveness so have more of a need for the stronger and lighter internals.

 

Either way I agree with your points and 459 vs 506 grams is nothing to scoff at.