RHS/INDY heads on 340

-
D

D-mailman

Well-Known Member
Joined
Aug 24, 2004
Messages
569
Reaction score
31
Location
Lexington,ky.
I believe the new RHS/INDY 360X heads would be just about perfect on a hot 360 engine for the street. Has anyone installed these on a 340 for the street ? They were intended for a direct bolt on replacement for the aging and now hard to find factory X,J heads. They are bigger in port volume than the early factory castings and with a better chamber. Thanks.
Terry
 
Not exactly a "direct" replacement because the Indy/RHS heads have smaller, closed chambers. You would have to watch the piston-to-head clearance on the older high compression 340's or any that have had higher compression pistons installed.

Intake ports are almost 20cc larger and exhausts are bigger too. But they should work well on a 340 on the street.

Specific head bolts from ARP are recommended and you'll need to do some research on valve spring installed heights with the Magnum-style valves.
 
I'm planning on using these on my 340 build. Since I'm planning to use the TRW L2316F pistons, which normally stick out about 0.016", I'll be using a 0.060" head gasket to get 0.044" piston to head clearance with the closed chambers.

IIRC they use magnum style head bolts. I'm also planning to use a Hughes ALN2228 hydraulic roller cam in this build.
 
goldduster318 said:
IIRC they use magnum style head bolts. .
Click to expand...

Do a little research. I believe Brian (ou812) said that he got ARP to make specific head bolts for the RHS/Indy heads because the OEM Magnum heads were, I believe, just a bit too long. 144-3606 It's mentioned in one of the older threads about the heads.

Not sure if the Magnum bolts won't work at all of if they are "iffy", depending on how the blocks and threads are machined.
 
I have a set of these heads getting built right now, they were flow benched yesterday out of the box and they only flowed 208. A stock head does that. Not impressed so far. The heads I have are shaft rocker, but they have castings in there for the magnum rocker stud, that are has to be ground out of each port I guess, it is a huge bump in the roof of the ports I guess.
FYI.
 
208..WOW, My flow bench is on the conservative side and on my bench I saw 251 cfm out of a as cast unported set with 2.020 valve @ .550 . I don't know..yes the old castings will flow 200-206 range @ .500 unported. Something IS wrong .have them tested at another shop just to know. Let us know.
 
Locomotion said:
Do a little research. I believe Brian (ou812) said that he got ARP to make specific head bolts for the RHS/Indy heads because the OEM Magnum heads were, I believe, just a bit too long. 144-3606 It's mentioned in one of the older threads about the heads.

Not sure if the Magnum bolts won't work at all of if they are "iffy", depending on how the blocks and threads are machined.
Click to expand...

Correct! Some blocks are OK with the magnum bolts but many are not.
Even with a stock 1.92 intake valve and no backcut they should flow about 244 @.500 and 250 with a back cut.
With the 2.02 valve and blended bottom cut they will flow mid 260's @ .500 with NO porting.
Make sure you use a flow radius on the inlet of the intake port.
Brian
 
You must log in or register to reply here.
-

Back
Top