Simplify the amc 4.2 for me please - Pirate4x4.Com : 4x4 and Off-Road Forum

lrmoffraod · 08-07-2012, 04:32 PM

Hey guys i have a 1987 jeep yj 4.2 automatic np231. 9 inch ford rear and dana 44 front. This is a dedicated trail rig. Will never see road time. I just completed the mc 2100 conversion along with the nutter bypass. Plans this winter is to pull out the dash and all the bullshit that is usless and fab a new dash with only the few gauges i need. so here is the question, after doing the nutter bypass and mc 2100 swap which took care of alot of vac lines, is there anyway to pull the rest of the lines out and do it "old school" i guess. Just the few vac lines for brake booster and distributor? Or does this motor still run off of vacuum and need a few things? Would a person be better off doing a motor swap to a v8? I love this motor cause it has plenty of torque, i just want the necessities and that's it. And i have searched here, Google, Yahoo, and everything else and have not found a clear answer. Thanks in advance.

RANGERROD · 08-07-2012, 04:37 PM

I had a weber on my 4.2 just had Two lines one to distrubtor one to brake booster. Everything else capped off and nutter bypass performed.

CtChevy · 08-07-2012, 04:57 PM

So I have a 88yj 4.2 I ripped all the factory crap off the motor picked up a modded inline 6 gm hei distibutor to work in the 4.2 and swapped on a 2100 I plugged all other holes in the intake and run one vac to booster and one to the dist. Engine runs great simplest set up ever, power to the dist and starter to make run and a wire to the alt. And two vac lines cant get much easier.

lrmoffraod · 08-07-2012, 05:30 PM

thats what i was wanting to hear. thanks a lot guys. dont plan on swapping the distributor just yet but will be looking into it in the very near future. with my 2100 i started with the screws a turn and a half out. does the timing need to be set at 8 degrees? or did i read wrong?

Mulely · 08-07-2012, 05:40 PM

I had the 390 Holley carb and offy intake with an hei dizzy. Ran awesome. 12 degrees initial ignition timing and an msd box. Full out burnouts on 35's and gobs of torque at like 600 rpm. Forget the 2 barrel stuff.

Sent from ma fone

hineyman · 08-07-2012, 09:35 PM

MSD Atomic fuel injection.

may pop · 08-18-2012, 08:03 PM

Ive had a few AMC 6s in various trim and the best mod was always the HEI swap. Better starting,smoother idle, just runs better.

Ron

An original SIX offender

jeepnitreal5 · 08-19-2012, 01:28 PM

Quote:

Originally Posted by RANGERROD

I had a weber on my 4.2 just had Two lines one to distrubtor one to brake booster. Everything else capped off and nutter bypass performed.

I would run a PCV valve. My freind decided he didnt need one a j20 and kept getting oil under the dist cap.

08-07-2012, 04:32 PM	#1 (permalink)
lrmoffraod Newbie Join Date: Sep 2011 Member # 199798 Location: crossville, tn Posts: 31	Simplify the amc 4.2 for me please Hey guys i have a 1987 jeep yj 4.2 automatic np231. 9 inch ford rear and dana 44 front. This is a dedicated trail rig. Will never see road time. I just completed the mc 2100 conversion along with the nutter bypass. Plans this winter is to pull out the dash and all the bullshit that is usless and fab a new dash with only the few gauges i need. so here is the question, after doing the nutter bypass and mc 2100 swap which took care of alot of vac lines, is there anyway to pull the rest of the lines out and do it "old school" i guess. Just the few vac lines for brake booster and distributor? Or does this motor still run off of vacuum and need a few things? Would a person be better off doing a motor swap to a v8? I love this motor cause it has plenty of torque, i just want the necessities and that's it. And i have searched here, Google, Yahoo, and everything else and have not found a clear answer. Thanks in advance. __________________ 87 yj 4.2 auto np 231 9 inch ford rear dana 44 front h1 recentered wheels on 37's. full cage. stretch and 4 link front and rear when the funds are there to do it

08-07-2012, 05:30 PM	#4 (permalink)
lrmoffraod Newbie Join Date: Sep 2011 Member # 199798 Location: crossville, tn Posts: 31	thats what i was wanting to hear. thanks a lot guys. dont plan on swapping the distributor just yet but will be looking into it in the very near future. with my 2100 i started with the screws a turn and a half out. does the timing need to be set at 8 degrees? or did i read wrong? __________________ 87 yj 4.2 auto np 231 9 inch ford rear dana 44 front h1 recentered wheels on 37's. full cage. stretch and 4 link front and rear when the funds are there to do it

08-07-2012, 09:35 PM	#6 (permalink)
hineyman Livin' the dream Join Date: Aug 2006 Member # 77297 Location: Magalia, Ca. Posts: 426	MSD Atomic fuel injection. __________________ Nothin' is holding you back but fear and good common sense. Thanks to Axial Racing,Yukon, Crystal Basin Mt. Resort, Norcal Crawlers, MSD,P-ville Kiwanis,El Dorado Rotary,Metalcloak,Magoon Signs,www.4wdmechanix.com, Northstar Eng,Crawl,FOA,AND BFG for supporting WFTW.

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08-07-2012, 04:37 PM	#2 (permalink)
RANGERROD Ajs biggest fan!! Join Date: Oct 2010 Member # 172656 Location: st helens or Posts: 992	I had a weber on my 4.2 just had Two lines one to distrubtor one to brake booster. Everything else capped off and nutter bypass performed.

08-07-2012, 04:57 PM	#3 (permalink)
CtChevy Granite Guru Join Date: Jan 2007 Member # 85204 Location: CT, AKA NO PLACE TO GO PLAY Posts: 531	So I have a 88yj 4.2 I ripped all the factory crap off the motor picked up a modded inline 6 gm hei distibutor to work in the 4.2 and swapped on a 2100 I plugged all other holes in the intake and run one vac to booster and one to the dist. Engine runs great simplest set up ever, power to the dist and starter to make run and a wire to the alt. And two vac lines cant get much easier.

08-07-2012, 05:40 PM	#5 (permalink)
Mulely Registered User Join Date: Jul 2009 Member # 139297 Posts: 35	I had the 390 Holley carb and offy intake with an hei dizzy. Ran awesome. 12 degrees initial ignition timing and an msd box. Full out burnouts on 35's and gobs of torque at like 600 rpm. Forget the 2 barrel stuff. Sent from ma fone

08-18-2012, 08:03 PM	#7 (permalink)
may pop Registered User Join Date: Sep 2005 Member # 53564 Location: Lake in the Hills Il. Posts: 77	Ive had a few AMC 6s in various trim and the best mod was always the HEI swap. Better starting,smoother idle, just runs better. Ron An original SIX offender