Posted By: RyanJ
418 RHS/INDY LA-X Head Motor on Dyno - 08/31/10 12:37 AM
340 block 4.08" bore
Eagle 4340 4.0" Crank
6.123" H beams
KB Forged dish pistons
10.3:1 Compression
Milodon 7 QT Pan, Moroso electric water pump
INDY/RHS LA-X heads, 2.055"/1.60" valves
Heads got 5 angle valve job, back cut intake valves, bowl ported & little pushrod pinch work. No flow #'s
1.5:1 Rockers
Bullet Solid "street" roller, 264/268 @ .050", 108 LSA, .604"/.594" lift, Herbert lifters
Crane 3/8" pushrods
INDY 360-3 Oval port intake converted to std pattern/rectangle port.
Ran 3 different carbs on it, 950HP, 750 Proform, 830 Holley
The 950 worked best... the 830 was junk, The 750 was only down 3 HP, but off about 12-15 FT Lbs, & actually moved TQ band up about 300 RPM for some reason....
Never dynoed anything with magnum based on heads on it before.. Thought this combo may eak out 550, & was surprised when we surpased that on the 2nd pull.
The INDY intake was a wildcard & did what I hoped it would do.... it made TQ... It would have been alot easier to run a victor or SV on this combo but I decided early on in the going that I'd try an ICH -3 due to runner length. This motor actually made better TQ than a 12.5:1 416 Edelbrock that had better heads, more cam etc. That had a SV on it... Granted that one made 50 more HP up top, but could not match this one for TQ. & the INDY was not hurting HP by any stretch of imagination....
I guess biggest surprise I had was how much timing it wanted.... was not happy making power with less than 38 degrees in it, would not have expected that...
This will be a real nice little street motor.... lot's of TQ right off the bottom, nothing radical, easy to work on... simple & straightforward.
Those RHS heads definitely work really well, without alot of... well work. For a more mild motor, they are by far best bang for buck head out there, especially considering how high E heads have gotten in price. Just have to be willing to live with the weight penalty of iron & the cooling differences etc.
Eagle 4340 4.0" Crank
6.123" H beams
KB Forged dish pistons
10.3:1 Compression
Milodon 7 QT Pan, Moroso electric water pump
INDY/RHS LA-X heads, 2.055"/1.60" valves
Heads got 5 angle valve job, back cut intake valves, bowl ported & little pushrod pinch work. No flow #'s
1.5:1 Rockers
Bullet Solid "street" roller, 264/268 @ .050", 108 LSA, .604"/.594" lift, Herbert lifters
Crane 3/8" pushrods
INDY 360-3 Oval port intake converted to std pattern/rectangle port.
Ran 3 different carbs on it, 950HP, 750 Proform, 830 Holley
The 950 worked best... the 830 was junk, The 750 was only down 3 HP, but off about 12-15 FT Lbs, & actually moved TQ band up about 300 RPM for some reason....
Never dynoed anything with magnum based on heads on it before.. Thought this combo may eak out 550, & was surprised when we surpased that on the 2nd pull.
The INDY intake was a wildcard & did what I hoped it would do.... it made TQ... It would have been alot easier to run a victor or SV on this combo but I decided early on in the going that I'd try an ICH -3 due to runner length. This motor actually made better TQ than a 12.5:1 416 Edelbrock that had better heads, more cam etc. That had a SV on it... Granted that one made 50 more HP up top, but could not match this one for TQ. & the INDY was not hurting HP by any stretch of imagination....
I guess biggest surprise I had was how much timing it wanted.... was not happy making power with less than 38 degrees in it, would not have expected that...
This will be a real nice little street motor.... lot's of TQ right off the bottom, nothing radical, easy to work on... simple & straightforward.
Those RHS heads definitely work really well, without alot of... well work. For a more mild motor, they are by far best bang for buck head out there, especially considering how high E heads have gotten in price. Just have to be willing to live with the weight penalty of iron & the cooling differences etc.
