'64 Dodge with 440 ci.

[O'l geezer]

Tks 65 x 3

 

[dvw]

Not enough timing will slow it some. But it will not cause a miss. When does it miss? Only a the hit?
Doug

 

[O'l geezer]

Not enough timing will slow it some. But it will not cause a miss. When does it miss? Only a the hit?
Doug

Doug, the miss was at 5K. I advanced a couple of deg. and the miss went to 5500. going to try a couple more deg. hopefully later today. will post results.

 

[dvw]

Doug, the miss was at 5K. I advanced a couple of deg. and the miss went to 5500. going to try a couple more deg. hopefully later today. will post results.

Timing should not affect miss. Weve run stuff as low as 21 total.
Doug

 

[O'l geezer]

Timing should not affect miss. Weve run stuff as low as 21 total.
Doug

Hmm, I need to look at something else..

 

[O'l geezer]

Hmm, I need to look at something else..

Well I have been checking things and doing research on what could be my problem.
I have not found anything I can put my finger on, but I think the problem might be a fuel problem. We have a rebuilt engine. The heads had leaking valves, found sticking wrist pins bearing wear and all around wore out. Now that things are up to specks with a few goodies, I feel the car is launching a lot harder and causing the fuel in the stock tank to run to the rear and air is entering the fuel line causing starving the carb for fuel. It's amazing the car ran 12 second times before the rebuild. I started having trouble with rocker arms so i installed all new upper valve parts. when I went to adjust the solid roller cam rockers, two of them had to have too much wrench turns. We removed the intake and found 2 cam lobes wore out, due to two roller lifter froze up wiping out the cam. I decided to remove the engine to inspect the lower end and found the other problems. I plan on installing a carter high pressure fuel pump an putting a return line on. Hope this does it.........thanks everyone for your input.

 

[66Satellite47]

Was the roller cam setup new with the rebuild? Did the rollers fail? Which rockers? Retainer to guide clearance? If you have a solid roller cam motor seems like you should consider a big electric fuel pump with a big fuel line. Just my opinion.

 

[O'l geezer]

Was the roller cam setup new with the rebuild? Did the rollers fail? Which rockers? Retainer to guide clearance? If you have a solid roller cam motor seems like you should consider a big electric fuel pump with a big fuel line. Just my opinion.

Hi 66, the roller cam was the one I had trouble with. With the rebuild I went to a hyd. flat tapitt cam. the rockers are new steel type. Bob

 

[66Satellite47]

Guess I misunderstood. I agree with dvw, the timing won't cause a miss at 5000 -5500 with an MSD 35-36* total is typical and plug gap should be around .045. Fuel system is likely cause, junk in tank, small fuel line, too small fuel pump, low float level, wrong jetting? Or it's possible your new cam/lifters/valve springs are at their limit in that RPM range.

 

[HEMI-ITIS]

After the miss at rpm are you shifting? What carb are you using?

 

[fbs63]

I would make a pass with the High side rpm limiter chip out. The chips get old and start to cause this exact problem. And I think it needs more timing also.

 

[O'l geezer]

fbs63 I have a new MSD digital 6AL box.
Hemi-itis: when missing starts, I let off because I think it will harm something. The carb is a Quick Fuel 850 cfm.
66 I will ck plug gap with new plugs soon. Have been waiting for a new turn signal switch to come in. It is late and i have column apart. Should be here soon.

 

[PRHeads]

5500-ish is often where hyd lifters start giving up...... especially if it’s a faster rate type cam.

 

[O'l geezer]

PR, the man who rebuilt my engine has done 3 before mine. he used the same parts. the other 3 have had no problems. One of them has a 4 speed and shifts at 7K. Not saying that some parts were shipped wrong but he is a very picky engine builder. The cam is a special grind that he and a cam builder who now works for, I believe comp, cams. Anything can happen and if does I will be the one at the lead. Thanks to all for the advice. You guys are awesome...

 

[biomedtechguy]

5500-ish is often where hyd lifters start giving up...... especially if it’s a faster rate type cam.

FWIW, I suspected that the springs on the stock 452 heads on my 440 6bbl were weak when I first got my Roadrunner. I also had problems with a lifter or 2 collapsing when I missed a shift (shifter was a pile of mismatched crap)
Anyway I got all new Comp Cams hydraulic lifters, springs, locks, retainers, and pushrods and did a "new cam break-in" even though I had the same cam, which is definitely a Mopar FT Purple Stripe and I and others suspect it's the 292° .509" lift cam.
Ever since then my engine pulls VERY strong to 6,200 RPMs.
I have my shift light set at 5,800 and rev limiter set to 6,200. Before I had the rev limiter or a tachometer, 6,200 is just where it really wanted to go to.
I have NEVER detected any kind of valve train instability in the higher RPMs of that range, and I absolutely was right when I suspected the old components were worn out.
JMO
I know you have great experience PRHeads, but that is my experience with my engine.

 

[O'l geezer]

Well gang, after going through a wind storm and doing clean up on the 3 acres, I finally took the time and did some checking things out. I set the float level above level, installed new plugs gaped at .045". Did a test launch and hit 5000k rpm and it started missing.
Question, Can I install a small electric fuel pump at the tank and leave the mechanical pump still hooked up to try and see if the problem stays ?

 

[biomedtechguy]

Can I install a small electric fuel pump at the tank and leave the mechanical pump still hooked up to try and see if the problem stays ?

Yes, and my best friend did great with that setup on his 70 Roadrunner 383 4 speed. The electronic fuel pump had a pressure setting on it, and he kept the mechanical pump on it too.

 

[Dan64]

Have you checked/ changed anything with the rev limiter yet?. Also wondering which Carter mech. fuel pump and line size you have. I'm just spitballing, hope it's something easy and you don't have to get back in the motor ( lifters).

 

[O'l geezer]

Dan64, I had forgot to do anything with rev limiter, although it is a digital 6al box I will disable rev limiter and try that. The mechanical pump is an edelbrock and the line size is 3/8" all the way.
bioguy thanks for the comment. am going to try electric fuel pump, a Holly Red one.

 

[biomedtechguy]

bioguy thanks for the comment. am going to try electric fuel pump, a Holly Red one.

I'm not familiar with the details of that pump, but be sure to have some way to control the fuel pressure.
Let us know what happens.