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Ramjet distributor cap & rotor

26K views 18 replies 8 participants last post by  roger1 
#1 ·
For you guys running a ramjet system, as you may know the ramjet distributor cap has aluminum contact terminals, They wear out fast.

So after a lot of research I found a distributor cap and rotor made by msd that fits the ramjet distributor.

It has copper teminals and should last a long time.

MSD Distributor Cap and Rotor, GM External Coil (8406)

 
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#2 ·
Interesting. I didn't know that.
Thanks Otis.

How fast do the original type wear out?

Is it the same part for the 350 Ramjet as it is for the big block?
 
#3 ·
I never had a big problem with them on my old 95 pickup which uses the same distributor. I always thought the rotor was a total PITA because it was such a tight fit - you almost had to destroy it to remove it, and then you wondered whether you got the new one pushed down far enough.
 
#5 ·
Don, did you have trouble with the cap your RamJet came with?

Thx for the part #s.
 
#6 ·
I was concerned about the large gap between the rotor tip and terminal inside the cap. I had a miss and thought that may be the problem, but it turned out to be the billet bling wire looms. The original GMPP wires were arcing to the inside of the loom. I went with a insulated loom and MSD wires to solve the problem.
 
#13 ·
I started having trouble with my Ramjet 350 running a little rough a while back and didn't know what it was. It kind of got progressively worse. The engine was shaking a little and I thought I might have had a broken motor mount. Last week when it started to backfire a little after coming down from revving the engine a little in neutral, I ordered a new set of spark plug wires.

Today, I changed out both the wires and the distributor cap and rotor. I went with MSD Street Fire wires and the copper Napa Echlin cap and rotor. I pulled and checked all the plugs and gap and they were fine. The cap and rotor (also came with the RamJet) looked fine but I wanted to make sure I had quality pieces.

Took it for a long test drive. It has never run as smooth as it is now. I think it was the wires that made the difference. It seems to have more power too.

I'm wondering if the GMPP red wires that come with these crate engines are just junk. I only have 3K miles on the engine now and they've been acting up for a while. I think if I ever buy another crate engine that comes with these wires, I won't use them.
 
#14 ·
the gmpp wires are basicly the same as what you just purchased privately labled for gm. msd also makes the gmpp ignition box. the cap and rotor was probably the problem. Use an ohm meter and check the wires. less than 5k and they are good.
 
#15 ·
I just measured them. Looks like the old GMPP wires run about 1,000 ohms more that the new MSD wires. The old ones were all less than 3K and the new ones were all less than 2K.

You might be right but I do wonder if I might have had inductive cross-fire or some other kind of spark breach. Acardon has said he had trouble with his red GMPP wires arcing and had to replace them.

What would be the possible problem with my old cap and rotor? I sure didn't see anything out of the ordinary. Not sure what GMPP gave me with those but the cap does say made in the USA on it. When I inspected the old cap and rotor it did look the air gap was kind of wide as Acardon said too. But, when I looked at the new Napa Echlin set, it looked about the same to me.
 
#16 ·
I find the cap is usually the worst part as it has the poorest conductor in it and after a while it just seems to get worse. I only use brass terminal caps, and rotors for this reason. According to my friend at chevy the gmpp wires are relabled MSD street fire wires made for gmpp. I usually run the msd super wire 8.8mm, cost more but never had one fail. have had the street fire wires break down a couple times.
 
#19 ·
Sounds like I should have gone with better wires than the MSD Street Fire.
It seems good now though. If I have trouble again, I'll get better ones. I wasn't trying to save money, I looked at reviews on the Street Fire and they seemed pretty good.

Wires or distributor cap / rotor, 3K miles is ridiculously bad.
 
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