Anyone make Undercut Stem AMC Valves????

amundaza

Does anyone make AMC Stainless valves with 5/16" Undercut stems in the runners ..... there a gobs of undercut stem valves for Chevy/Ford/Mopar. I've done the valve swap on 258 heads to Chevy 1.94" int &1.50" exhaust using Milodon Megaflow valves (undercut 5/16" stems in runners) and picked up GOBS of useable torque and power in low-mid RPMS. Has ANYONE come out with these for AMCs ... it would save about $250-$450 in machining for Chevy valves.

jeepsr4ever

I dont recall any for that size. Most use the chevy guide 11/32".

bryancsherman

The SI valves are undercut in the flow area, but standard diameter in the valve guide area. Just search for SI Valves and you will find them on the web. Good valves, I run them and I know lots of other people who do as well. :lo1l: Bryan

amundaza

bryancsherman wrote
The SI valves are undercut in the flow area, but standard diameter in the valve guide area. Just search for SI Valves and you will find them on the web. Good valves, I run them and I know lots of other people who do as well. :lo1l:

Bryan

Hi Bryan,
Tahnks for the information. I have been looking through their website and don't see the AMC specific undercut stem valves listed. What are the AMC part numbers you're running. I'm looking for valves for either my 1989 360 heads (2.02/1.68) or a set of small chamber 360/390/401 heads (2.02/1.62). Thanks!

Sincerely,
GregTaylor
Oxford, MI

1989 Grand Wagoneer : Water/Hydrogen Injection 360-V8. 4.5" lift 31" BFG A/T's. Killer32 front bumper

ed455

http://www.rpmrons.com/SIvalvesps_amc.html

http://www.rpmmachine.com/si-valves-amc-portflow.shtml

bryancsherman

Ed got the right links, you should have no trouble now! Thanks Ed and great valves :lo1l: ! Bryan

amundaza

Since SI makes undercut stem AMC valves, does anyone know if the 343-401 sized valves (2.02/1.625 or 1.68) could be cut down to SB Chevy head diamter (1.94/1.50) for use in a modified 290/304 head? I have been modifing 258/304 heads to use the SBC 11/32" stem, but if AMC valves could be run, cut down to Chevy diamters, that would alleviate having to bush the guides for Chevy valves. INTAKE: 2.02 - 1.94 = 0.080" difference EXHAUST : 1.625 - 1.50 = 0.125" difference Thanks for the feedback.Sincerely, GregTaylor Oxford, MI 1989 Grand Wagoneer : Water/Hydrogen Injection 360-V8. 4.5" lift 31" BFG A/T's. Killer32 front bumper

fifesjeep

Anything is possible... .080" for the intake = .040" per side.. .125" for the exhaust = .0625" per side which means re-cutting the angle(s) and possibly changing the radius or the backside of the valve for flow... (Most likely cutting down and recutting the angles). That's a lot of small PITA work which would probably cost more than it's worth, IMO.

amundaza

I'm just interested to see if cutting down the larger valves would be more cost effective, as compared to swapping in SB Chevy valves at 1.94/1.50 and having to install the smaller ID bronze valve guides. Thanks for the feedback. Thanks for the feedback.Sincerely, GregTaylor Oxford, MI 1989 Grand Wagoneer : Water/Hydrogen Injection 360-V8. 4.5" lift 31" BFG A/T's. Killer32 front bumper