Edelbrock Heads

pablorg

Hi, I am thinking of buying the Edelbrock MPFI and Heads for my AMC-360-V8-powered CJ-7... I was wondering if someone here could help me with these questions: 1) 4WD Hardware catalog recommends "Full Roller Rockers" and "Chromemoly Pushrods"... Where can I buy these for the AMC 360? Why are they needed? 2) Will the Edelbrock shorty headers work (fit) with the Edelbrock Heads? 3) Has anyone already done this MPFI conversion and how happy are you with it? Thanks a lot for your time.

tufcj

(1) Full rollers just mean that the tip is a roller and the fulcrum has bearings. They are available from major vendors like Crane and Harland-Sharp. You need hardened pushrods to run with the pushrod guide plates that are also required (included, I believe) with the Edlebrock heads. If you use standard pushrods, they'll wear where they touch the guide plate and put metal shavings into your engine. AMC pushrods are the same length as small block Chevy. Depending on the cam lobes, you may need a +.100" pushrod, which are also readily available. (2) I've heard of some fitment problems with the shorty headers and the Edelbrock heads. Most thick flange headers take a bit of clearancing for the head bolts directly under the exhaust ports. (3) I haven't done the MPFI myself, but I haven't heard any complaints from people who have installed them. Send a PM to MC (jeepsr4ever) right here at Bulltear. He's an Edelbrock distributor. Bob tufcj

Dusty

The pushrods are actually longer than +.100 which is what i originally got, i ended up ordering them through bulltear but they are supplied by Edelbrock to match teh heads, believe they were something like +.250 but dont quote me on that what ever they are Edelbrock offers them but seperate from the heads. Roller rockers are a must the heads wont work with bridged rockers, they come with 3/8" studs not 7/16". the heads take peanut sparkplugs. The heads have to be retorqued after 500 miles of driving they seep like a banshee soon after fire up uintil you retighten them. Also that are a tid mit thinner so your bracketry for AC, PS ect might have to be shimmed with a washer to get it all to perfectly line up. Have a machine shop check the valve spring pressure closed and open they should be 115# at the seat but my first set was 145#+ at the seat way too much for a hydraulic cam.the flow numbers are a little more on the heads find a cam company that will custom grind you a cam, mine is a ittle undercamd for what it is and i feel it had more potential. Yes there is a fitment problem with all headers on the heads, the head bolts stick up a little more because of the thicker mating surface. a grinder made my doug thorley fit but didnt leave me much confidence for surface area nor gasket life. i probably will got to the shorty headers as i think in a cj they offer more exhaust routing options The MPFI is a nice very adjustable setup. A word of advise on a jeep install an intank fuel pump. i dont care what anyone says the setup is thirsty and the frame rail mounted pump supplied with the kit is good when the tank is close to level with the location of the pump. but it is a pressure push pump not a suction pump and edelbrock has acknowledged that "some people" most who i know hwo have cj's with larger engines and this setup have had minor fuel starvation problem especially once past the 2/3-1/2 tank level it starts starving out at WOT sometimes at all positions other than idle. Edelbrocks suggestion at first was to build a bracket and lower the pump, otherwise they suggested a low pressure volume pump supplying a manifold that also accepted fuel coming back from the engine and then had a line supplying the tank and the manifold would then work as a constant supply of low pressure fuel for feeding and priming the pressure pump. Thier minimum specs are 100 gph and 60 psi though later they said i could probably get away with 60 gph and 60 psi Looking through summit i found a GM intank pump that met close to the 100 gph 60 psi requirement i am in the process of inserting a 3rd hard line into my tank that way i can have two pickups in the tank one with an attached intank pump (baffles are nice but not necessary, i have spoken with many who dont run them in retrofit cj tanks and have 3-5 years without any problems) the second line would keep the rubber hose and screen pickup so that ican retain the frame mounted pump then a manual ball valve on the frame rail will allow me to switch between the pressurized fuel coming from the intank pump or the fuel coming from the frame pump. then a toggle switch on the dash will deligate which will be doing the job. that way if the intank pump dies im not dead on the trail and/ or dropping the tank in an inconvenient place.

pablorg

Thanks Dusty and tufcj for all your valuable information. Dusty, did you have a carb before you installed the MPFI in the CJ? Is there a noticeable difference? Also one last question: does this setup have a crankshaft position sensor similar to what the 4.0L engine has or how does it pick up the signal? Thanks again,

Dusty

no crank position sensor. this setup gathers its pickup from the dristributor.

pablorg

Hi Dusty or tufcj, I ordered the chromemoly pushrods from Crane Cams (part # 86713-16) and when I opened the package with the pushrods, I get a warning label that says: "CAUTION: These pushrods cannot be used with guideplates. The tubing is not heat treated and will wear through at the contact point." :-| So.... should I use these pushrods with the Edelbrock Heads. Or a better question: do I need to use guideplates with the Edelbrock heads? Please help!

tufcj

Chromemoly doesn't mean hardened. You need pushrods specifically designed for guide plates. Don't use the ones you have, you'll end up with metal fragments in the oiling system. I do believe the guideplates are included and required with the Edelbrock heads. Guideplates keep the rocker arms from twisting to the side. Bob tufcj

pablorg

Dusty wrote
....Have a machine shop check the valve spring pressure closed and open they should be 115# at the seat but my first set was 145#+ at the seat way too much for a hydraulic cam.

Dusty,

I had a machine shop check my valve spring pressure on my newly acquired Edelbrock Heads. According to them the pressures at the moment are arround 175#+ and 220#+ :shock: Is this possible? They tell me they can lower it to 115 - 125, is this correct?

Thanks a lot for your help.

pablorg

Dusty wrote
...

The MPFI is a nice very adjustable setup. A word of advise on a jeep install an intank fuel pump. i dont care what anyone says the setup is thirsty and the frame rail mounted pump supplied with the kit is good when the tank is close to level with the location of the pump. but it is a pressure push pump not a suction pump and edelbrock has acknowledged that "some people" most who i know hwo have cj's with larger engines and this setup have had minor fuel starvation problem especially once past the 2/3-1/2 tank level it starts starving out at WOT sometimes at all positions other than idle. Edelbrocks suggestion at first was to build a bracket and lower the pump, otherwise they suggested a low pressure volume pump supplying a manifold that also accepted fuel coming back from the engine and then had a line supplying the tank and the manifold would then work as a constant supply of low pressure fuel for feeding and priming the pressure pump. Thier minimum specs are 100 gph and 60 psi though later they said i could probably get away with 60 gph and 60 psi

Looking through summit i found a GM intank pump that met close to the 100 gph 60 psi requirement i am in the process of inserting a 3rd hard line into my tank that way i can have two pickups in the tank one with an attached intank pump (baffles are nice but not necessary, i have spoken with many who dont run them in retrofit cj tanks and have 3-5 years without any problems) the second line would keep the rubber hose and screen pickup so that ican retain the frame mounted pump then a manual ball valve on the frame rail will allow me to switch between the pressurized fuel coming from the intank pump or the fuel coming from the frame pump. then a toggle switch on the dash will deligate which will be doing the job. that way if the intank pump dies im not dead on the trail and/ or dropping the tank in an inconvenient place.

Hi Dusty,

I was wondering if you had solved the minor fuel starvation problems you had, and which was your final solution... I am getting ready to buy the Edelbrock EFI and wanted to make sure I get it right from the beginning....

Thanks a lot