Chev Small Block

[T04GTR]

hey all. as the topic sugests, can you use small block 6" rods in a rb30? whats required?

experts only please, i know it been done but need the details. cheeres

[StealthX]

Rods are Rods, as long as the small end and big end bearings fit snug and their ok length, go for it.

I don't know shit about V8s internally, so i dunno if they have the same size bearings.

[StealthX]

Rods are Rods, as long as the small end and big end bearings fit snug and their ok length, go for it.

I don't know shit about V8s internally, so i dunno if they have the same size bearings.

[sorry for double post :| ]

Edited November 2, 2009 by turbo x-trail

[GTR1993]

This is old school, I remember reading it ages ago but I know it needs work, rebush small end or machine width of big end down, I cant remember.

[GTR1993]

due to the amount of interest, and the off topic posting in for sale threads i have decided to start this thread for discussion on fitting h-beam rods into rb30 engines

i am currently doing it with scat rods http://www.scatcrankshafts.com/FS_800.htm

they are small journal 6" chev h-beam rods.i got a set of 8 for $700 retail price.they need to have about 2mm machined off both the little end and big end thickness.they also need to have a nissan little end bush installed.chev bearings must be used as the dowels on the bearings are on the opposite side to nissan bearings.

i will be keeping tabs on all costs and and details on all machine work so others will not have to worry about what is involved.

anybody who has already done this please post what you have done to fit yours

copy from CT

[Spoolup]

This has been covered numerous times,

You will find it more expensive to do this procedure than to buy a set of rods designed for RB30

As mentioned about 2 mm is require to be machined off the b/e and small end sides, the small ends then need to be rebushed, the bearings also need to be narrowed, the b/e tunnels then need to be resized due to the narrowing process distorting the b/e tunnel of the rod. From memory 60thou Chev bearings are required, and then the std crank has to be machined 7 thou to suit the new b/e tunnel size.

[Alf]

I have a set of SCAT H beams identical to whats been mentioned in my 25/30.

All up it cost me $900 with machining done by myself.

When I was shopping for rods, Spool Conrods never replied to emails, pm's or messages left on the phone...and I waited months.

[Spoolup]

I reply to all my emails usually within 24 hrs - so I obviously didnt get yours.

I never reply to PM's

Sorry if I didnt reply to your phone message, but as I only have one number I do get alot of them.

I have a set of SCAT H beams identical to whats been mentioned in my 25/30.

All up it cost me $900 with machining done by myself.

When I was shopping for rods, Spool Conrods never replied to emails, pm's or messages left on the phone...and I waited months.

[T04GTR]

I KNOW I COULD JUT BUY rb30 ones but when i can get some nice carrillos for next to nothing with pressure wrist pin oiling (will be drysumped) one must ask...

also it my open some options for na motors using 25 or 26 pistons with 6.1 or 6.2" rods to bring the piston up higher for a high comp ratio.....

[Adriano]

Its exactly as spoolup said. I have chevrods in my rb30, as rb30 rods weren't available at the time, its the 7 thou off the crank with 60 thou oversize bearings that i dont like, as it gives no room to move in the future if there are dramas.

[Swiper the Fox]

My mate who builds 888 racing's engines is also an RB30 guru...he buys Argo's off me so id question why he isn't using the pile of Carillo's he has access to. He's in the states at the moment...ill have a chat to him when he gets back and call you Dave.

[proengines]

I machined a set a while ago for a bloke who had already bought them. I had to narrow the rod and machine the outside of it to allow it to fit down the bore, they weren't made to fit an 86mm bore. These rods also needed the small end narrowed to fit between the pin bosses.

Now that there are good quality rods made specificaly for the RB30 at a good price, it's a bit of a waste of time unless you can machine them yourself and buy them very cheap to start with. Most of the used nascar rods for sale are too long (6.2-6.3") to start with though they do run Jap bearing sizes and metric pins. You do need to remember that stuff is used as well and you don't have rod bolt lengths to compare to original and it is probably worth having them crack tested. Some of them also aren't bushed on the small end and require a DLC coated pin, check the price on them..

In all honesty I'd just buy a set of Spool rods, great price, excellent dimensionally and weight-wise and I haven't seen a broken one yet. I used them in an engine recently that ran 3rd (i think) in the last Superlap event and recently had the engine apart and they looked and measured like new.

[Spoolup]

I knew there was something I forgot :-) Thanks Greg

"and machine the outside of it to allow it to fit down the bore"

Allow a easy $130 plus per rod to get all the machining done, plus the intitial cost of the rods.

[Guilt-Toy]

http://www.tweakit.net/shop/product_info.p...1ven206ei62jk95

$850 for a set of rb30 rods

[proengines]

I haven't used the Precision rods. Anyone who has, can you tell me if they really use a 5/16" rod bolt in them? surely not. Maybe if they were an L19 or Carr bolt it may be a different story. I know some scat ones used to on the SR20 and 3S toyota rods but even they have 3/8" bolts now. Thats a lot of load on a little bolt! Spool and most others run a 3/8" bolt.

[T04GTR]

does anyone do rb30 rods with pressure wrist pin oiling?

[T04GTR]

this is the only reason id be inclined to get same nice penkle or carrillo's average weight of most of the ones ive seen is 520~gms

[proengines]

There's not many rods around with forced pin oiling until you get to the top end stuff as the holes are usually edm'ed to keep the diameter down. I don't think it's a big benefit unless you're running a vacuum pump and pulling all the oil vapour out of there. A couple of small cuts with a small ball end milling cutter on the thrust face of the big end sends plenty of oil up to the pin and under the piston.

[T04GTR]

oh ok cool.

yeah 5 stage daley engineering pump with roots scavenge.

[proengines]

You can get a vacuum relief valve to limit the amount of vacuum the pump will pull in the crankcase. Vacuum is a big benefit as long as you still get the oiling you need and piston pins are one of the things you need vapour/splash for, particularly in engines without piston oil squirters. A roots gear set is a pretty good vacuum pump, particularly when it's well oiled and you have 4 of them sucking so pressure fed pins or a squirter might be a good idea in that case. A .5-.75mm deep cut with a 2mm ball end milling cutter on the thrust face of the big end pointing directly at the pin would work well to get oil up to the pin and under the piston if you don't want to go the edm route.