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| Engine, Not right https://slantsix.org/forum/viewtopic.php?t=47657 |
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| Author: | Rick Covalt [ Sat Jan 21, 2012 3:09 pm ] |
| Post subject: | Engine, Not right |
Well I have a problem with my new engine in my car and for the life of me I don't know what is going on. Hope it is something simple. First, What I have. A Jasper rebuilt engine, that I placed a big valve head on. The head had new seats and valves and guides installed. I had a used cam that was .490 lift that was installed at 98 degrees intake centerline.( 4 degrees advanced) I have a new blaster coil, New HEI module, new cap rotor and wires. I have a known good 500 CFM carb on it. What it does. When I pump the gas it will fire off but will barely keep running. It sounds like something is way out of time or something. I can pump the gas while it is running and it is just like it is not getting fuel. Then all of a sudden it will speed up almost on its own and then it will shut off. When it shuts off it stops right now. As in quickly. It is very loud with open headers in the garage, but it just sounds wrong. It is not backfiring through the carb. What I did - I actually thought maybe I had the cam in wrong. That is how bad it sounds. So I pulled the radiator and mounted my degree wheel, and checked the intake centerline (This was off the rocker adjuster bolt) and I got about 96 or 97 degrees. Not exactly 98 where I thought it was but with how I was measuring it was close. So I put it back together. I put the distributor in 10 different times. No dice. Actually Ryan helped me today and you can see the timing mark at just about 10 BTDC while we cranked it over. So that should be close too. I took the carb off and placed it on another truck and it sat there and ran fine. Re-install carb. I replaced the HEI module with another new one. It acts the same. I rechecked the HEI wiring and it is correct. ( I have installed 2 other ones and have had no problems) All vacuum lines are plugged, PCV valve hose is plugged. I have a new thick intake gasket, new carb base gasket and gasket between the carb plate and intake is new. No open ports anywhere. It has new fuel in it. I disconnected everything that wasn't needed to eliminate any problems ie. low oil pressure cut off, tach wire to coil...etc. We ran a compression test and all the cylinders were between 145# and 160#. I checked the air gap on the distributor pick up. I'm really sorry this is long, but I'm stumped, or stupid, or both. I would appreciate your help. Maybe this is a bad dream. Rick Covalt |
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| Author: | kielbasa [ Sat Jan 21, 2012 3:19 pm ] |
| Post subject: | |
Did you accidently fill it up with diesel? |
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| Author: | slantzilla [ Sat Jan 21, 2012 3:30 pm ] |
| Post subject: | |
Rick, make sure you have a good seal between the carb mounting plate and the intake. They will act just like that when you have a vacuum leak under the plate. Weak spark will do the same thing. |
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| Author: | Rick Covalt [ Sat Jan 21, 2012 3:40 pm ] |
| Post subject: | No |
No to the diesel. Dennis, I will pull the carb and check it again, but I did pull the plate yesterday while I had the carb off and it looked fine. Rick |
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| Author: | USAJon [ Sat Jan 21, 2012 3:49 pm ] |
| Post subject: | |
try a points dist test run sounds eletric 2men |
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| Author: | emsvitil [ Sat Jan 21, 2012 3:54 pm ] |
| Post subject: | |
What's the fuel pump pressure? I'm thinking not enough gas is getting to the carb. |
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| Author: | Rick Covalt [ Sat Jan 21, 2012 5:17 pm ] |
| Post subject: | Fuel pressure |
Quote: What's the fuel pump pressure? Sorry, I don't have a fuel pressure gauge. I didn't have fuel to the carb at first, and I had the current pump in my garage. It looked nearly new, but I'm not sure where I got it. I put it on and got fuel right away, but I don't know the pressure.
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| Author: | ceej [ Sat Jan 21, 2012 6:39 pm ] |
| Post subject: | |
Why 98° ? Which cam are you running? CJ |
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| Author: | Rick Covalt [ Sun Jan 22, 2012 5:28 am ] |
| Post subject: | Cam |
Ceej, I got the cam used. Gentleman thought it was a MP cam. He had run it for just a short time in his car and didn't like it on the street with an automatic. I measured the lift at .490 (with 1.5 rockers) And when I looked up that cam I found a 102 intake C/L. When I installed it the bushings I had got me to 98 and I thought 4 degrees advance would be fine. I since have seen that cam listed at 104. I honestly didn't know exactly what I had for sure. But the plan was for this to be a short term engine until I get my "real" motor built. Rick |
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| Author: | Dart270 [ Sun Jan 22, 2012 6:04 am ] |
| Post subject: | |
No problem with 98 deg cam timing. I've played around some and ran the '64 Dart at 96 for the last several years. Ran a MP 0.490" at 99 deg for about 7 yrs and that was near perfect. What valve lash are you at? Back em off to 0.030"/0.030" and see if that helps. The MP 0.490" is listed at 0.028"/0.032" and I ran mine just a smidge tigher (around 0.026"/0.030"). However, I also vote for weak spark or a carb baseplate leak. I like the points dist try. Dead simple test. I had the Pertronix in Project V hooked up to the hot wire AFTER the ballast, and it did just about what you are describing. Don't worry, you will fix it! Lou |
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| Author: | Rick Covalt [ Sun Jan 22, 2012 11:58 am ] |
| Post subject: | valve lash |
I am not sure where I am on lash. I will have to check, but I think I set them at 18 and 26 cold. So I will back them off tomorrow. I am pretty sure have a point type distributor I can drop in to check that out. I probably will just get a new fuel pump while I'm at it too. I did check the Ohm readings on the Blaster coil and it was right on according to their web site. I may have to grab 2 small mufflers to bolt up to the headers too. It is very loud in the garage. Then I can hear a little better. I'll report back, Rick 99% sure it is not a base gasket leak. |
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| Author: | USAJon [ Sun Jan 22, 2012 12:09 pm ] |
| Post subject: | |
I still think it's eletric you know you can back fill a carb manually and it should start/run until empty I do it on starting sitting cars we buy also using choke too. just be careful fire ! ! ! I do it outside/no garage |
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| Author: | Dart270 [ Sun Jan 22, 2012 12:18 pm ] |
| Post subject: | |
Valves are very tight if MP 0.490" cam. Sleep well tonight - it will work soon.... Lou |
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| Author: | ceej [ Sun Jan 22, 2012 2:55 pm ] |
| Post subject: | |
Sounds like your onto something with the lash. A few thoughts: The adapter plate that goes into the Offy/Clifford manifold has four screws. A leak at that point had us chasing our tails for a bit. It's unlikely to be what your experiencing, but I got in the habbit of sealing the heads of the countersunk screws with RTV after that. Sealed them up, and it ran fine. It messed up the idle/transfer circuit somehow. A standard square bore gasket can be marked and punched for the adapter to manifold. I skin both sides of that gasket with RTV now as a precaution. Double check the adapter to make sure it's flat. I've had those warp. They don't seal worth a plug nickel once that happens. I also stopped using phenolic spacers after that fiasco. I've not experienced warping with the aluminum four hole spacers. After buying a new one, I took the old spacer and put it in my press between two iron plates. It straightened up fine, though generally with aluminum that won't be the case without preheating. CJ |
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| Author: | Dart270 [ Sun Jan 22, 2012 6:35 pm ] |
| Post subject: | |
Every stock Offy adapter plate (from offy) I've seen is junk. They are some knid of crap pot metal and warp/distort very easily. Lou |
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