Thread: Edelbrock Performer RPM Intake Manifold

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Hello, I was thinking about putting this manifold on my 1973 ford Ranger pick-up, it has a 390. I really don't wanna lift that heavy iron one back up there. The only problem i am concerned with is this manifold doesn't have the exhaust crossover passage. Is this going to be a bad idea? My truck currently has the factory 4 barrel intake. It has a so called RV cam in it. The motor has like 195psi compression, its got those flat-top pistons with 4 valve indents on them. It also has hardened exaust seats, and stainless valves. The carb is a 625 cfm webber/carter AFB. I really don't know if it is ok to just not use a manifold without this exhaust crossover passage, and if i do not use a manifold with the passage if i need to do anything special. I am also wondering what's going to happen when the truck is cold.

Joe i have the same intake on a 66 t bird 390 that i just recently built. The cross over is not needed in an aluminum intake becuase aluminum heats up much faster than cast iron that is the reason for the lack of the crossover on the intake,you wont experiance any prob's with it when cold.

Back to your question about how it will do when it is cold

Over the years I have run various motors without heat crossovers or blocked off crossovers. Generally speaking, if the vehicle is going to be street driven in cool/cold weather (anything 50 degrees or below), your going to wish you had it. Many engines will not run properly until the manifold has been completly warmed up. Without a functioning heat crossover it may take quite a while for the proper temp to be reached.

I just completed a 351W with preformer RPM heads (no heat crossover). I live in SE AZ and figured it would be no problem, just my luck, a couple of weeks ago we had a spell of unseasonably cold weather . On those 30 degree mornings, I wish I had gone with preformer heads with the crossover as it took about 10 miles before the car started running well.

MrMustang,
Is my current carb too small for this motor? I just received the specs on the motor, from the dude i bought the truck from. It has a Crower Cam, part number, 16915 - FORD 332-428 BAJA BEAST HYDRAULIC CAM (268-H). The lift on this cam looks to be .484 intake and .495 exaust . The gentleman i purchased truck from said he had a single plane weiand on it, and that it ran like crap with this manifold. He also had a different carb on it. The afb i have may need seals on the accel pump, i may just toss a rebuild kit at it. I really didn't wanna be messing with this truck, baahhh. Basically the truck started to have a bad miss, so i ran a compression check, and i had low compression on cylinder 1 i had 135psi 2,3,4 i had 195, 5 was 170, 6 was 185, and ;7,8 were 195psi..... I then did a wet test it came up the same. Rather then do a leak down, i just tore the heads off. While taking the intake off i notice the damn carburator nuts were all loose. Would loose carb nuts create this lean condition? I brought the heads into a machine shop. The fellow, at the shop, said i was running lean and heated some exaust valves too hot. The shop is going to put new seats in where needed. This truck is a friken money pit. bahh i gotta stop thinken about it. Maybe i shall slap the factory intake manifold back on. Will this Carter AFB 9637sa0516 suffice on this engine the way it is built. I was told it is a 625 cfm.

thanks for all the help thus far.

Joseph

I'm not sure about the carb but 390 fe's came out with 2100 motorcraft two barrels at about 500 cfm. It sounds like you got some serious problems with #1 cylinder - that's enough to make it run rough.

I have my heads back from the shop. The exaust seats were fine, for they had hardened seats. I did mess up a few intake seats, so they installed a few hardened ones there too. I have a 7282 weiand manifold, and a 625 cfm edelbrock carb. Does this sound like a reasonable combo for a 390 motor. I hope the manifold works ok, its sort of dual plane, it has slot down the middle, but if you shine a flashlight back in there it appears to be open back in there. Seems kinda odd to to go through the trouble of casting it half way, anyone know what i am talking about, or what's the deal with this type of manifold. I have read that i can torque manifold to normal factory specs.

Thanks for any replies.

Just a note on the non heat passage intake manifolds. You can really tell the development on these wasn't done in the northern states. Here in Michigan blocked or non existant heat crossovers don't make it. From mid November till mid April. Any time the air gets below 35 degrees and the humidity gets high you have a softball dize chunk of ice for a carburetor in about 20 miles! At best the throttle plates freeze and you can't slow down the motor or the idle circuits just freeze up solid so you have to let it set 15-20 minutes to melt. Then refire the water-gas mixture in the manifold. The only way you can drive these is with an Afro-engineered hot air intake off the top of the headers or exh manifold. Duct tape and dryer vent hose works well! Been there many times thru many rods, in my misspent youth!!

Well, here is an updadate.

I have installed the Weiand intake manifold, the rebuilt 625 cfm carb, the thorley headers. I then brought the truck in and had a Pro shop tune the carb and set the timing and play with the advance curve. This truck has electronic ignition and a mallory coil of some sort. The vacuum advance is not hooked up, it is being done with springs, and weights i believe. The advance curve seems to be better, way more power accross a nicer power ban, BUT when i get on the freeway, i am having detonation pings when i stomp on it. The engine is at roughly 3000 rpm when this occurs. I have super unleaded gas in this thing, and just to see, i dumped an octane boost in one of the fuel tanks. IT STILL has that PING at higher RPM acceleration. My compression is an average of 190psi, in this 390 motor. Is retarding the timing the only thing i can do? Or will that heat up my valves again. Maybe i should just poor a bunch of gas on this truck, and burn it. This is really frustrating. Any suggestions very much appretiated. I didn't have enuff money to just let the shop fix it, so they did roughly 5 hours of work.