iLL-Mitch

iTrader: (10)

I got an OS vspec... I was replacing the bearing and noticed slight play between the rod and crank... do i need to replace the rod or crank?...

jaylude22

iTrader: (93)

The only way to know which needs replacing is to measure the crank pin with digital calipers. Measuring it means you need to know what the original size was/is to know if it's within specifications. If I remember correctly, the original diameter is 5mm. Someone else may be able to chime in and specify how much smaller the pin can be without causing a problem. V-specs are somewhat notorious for this problem because unlike the Speed/JX-21(or just about any of the nova motors), they don't have the small hole on the front side of the rod to allow the oil to pass through to the crank pin. The lack of lubrication causes the components to wear much faster than they otherwise would.

mugenb46

iTrader: (4)

If you have around 2 or 3 gallons on it yes replace the rod, also inspect the crank pin, if it look's egg shaped it's almost going to decrese the life of a new rod. 2 or less gallons a new rod should do the trick.

iLL-Mitch

iTrader: (10)

i prolly ahve min of 4 gallons ill look at it and let you all know. Thanks

chunk t

Mitch, I'm going to partially disagree with Brian. Definately check the crank pin's roundness. My rule of thumb can be applied to any displacement engine. If the differance in concentrisity of the pin is 10%(or greater) it's gone.

I don't replace rods based on "X" number of gallons through an engine. I measure head clearance and port timings. These change as the rod & pins wear. Once they fall out of the range I need to maintain my performance envelope, then I'll swap rods (yes there other factors that will make me change a rod but those are case by case). Also, once you swap rods the crank pin will wear quicker in the beginning because the rod & pins are not a matched set like the originals were.

So, I guess what I'm saying is don't change the rod unless you have a good reason. and I've never been able to call a few gallons a good reason.

jpalessi

iTrader: (55)

It that point just RUN IT! it's not worth the money to start replacing parts..it'll run good for another gallon or two.. more likely then not, the crank pin is already out of round. If it was a speed, or a JX, i would say replace the rod, with the DLC coated crank those engines are worth rebuilding. How much play is there? 00.02 is normal.

CarCrazy

Run it...

fast11970

iTrader: (1)

I had a V spec that I was worried about...Had a Gallon thru it an got it hot...Took it all apart, I determined the Con Rod Was bad...Ordered a new one...Mistake, It had the same play, the same run out, as the one gallon con rod, This was about 6 gallons ago, I still do not trust the engine...But I seem to run it alot when my "Modded" mills have "Issues".. Same Con Rod, I gave the new one to a buddy his lookedmore worn than mine!

I would not worry about the play yet...If you are running, an It aint got no punch or you start to eat plugs...Then a V Spec needs some lovin...


IMO (In Monkey's Opinion!)

JAMMINKRAZY

iTrader: (17)

I have about 6 gallons on my stock v-spec without changing anything. If it has alot of play, measure the crank pin and check it for roundness. if it is within spec replace the rod and run it. If the crank is out of spec run it and enjoy it while it lasts. It isn't worth replacing the crankshaft(pretty much on any motor).

pinky2252s

iTrader: (4)

I had over 10 gallons on my TRX2.5.... hell it got slower but it still lasted

I never replaced a thing besides the clutch and a OWB or two

GH Racing

iTrader: (3)

After 4 gallons, I would change the rod

o.s. power

iTrader: (14)

no one has posted this yet - if you replace the rod in a stock v spec, get the speed rod, that has the oil hole in it to prolong the life.

a few of the guys i race with replace the stock rod right after break in for a speed rod and when they rebuilt the engines, they put a speed crank in there to.