Firing up the Ramjet 502!

[chevynut]

Congrats! The engine sounds like it has a fairly smooth idle.

I wouldn't call it "smooth" and it sounds great to me but the cam isn't that wild. It's a custom grind single pattern cam from Mike Jones Cam Designs with a 108 LSA, 226 degrees I&E duration and .610" intake lift with 1.8 ratio Scorpion roller rockers and about .585" lift with 1.75 ratio exhaust rockers. I didn't want a high RPM cam for this engine because it's strictly a street engine (6000 RPM max), so I wanted a lot of torque down low and to run well at 5000 feet elevation. So we went with a pretty early intake closing angle since the engine only has 9.7:1 CR. He tells me I should get over 600 ft-lb of torque and a wide torque band, which is what I was looking for.

I'm trying to get a video of it with better sound quality. I didn't realize it was that hard to get decent sound reproduction from a phone or camera. I took another video today but it's still not that good, especially through the mufflers (which sounds great). I'll try again tomorrow.

Thanks y'all!!

[Bitchin'57]

I listened to it again more closely with the speakers turned up, and I could hear a slight bit of chop to the idle. It sounds good. Gotta have a little bit of a choppy idle when putt-puttin' around the show field!

[JT56]

Congrats to you...getting closer to getting behind the wheel and really enjoying the fruits of your labor. Car has a good balance of old, new and custom design...I am happy for ya!

[chevynut]

Here's a video with better sound . I decreased the image resolution to make a smaller file but it's still pretty huge. I can't get a good video with the sound through the mufflers for some reason but it sounds really good. After this video I warmed up the engine to operating temp and checked the timing against the ECU and synced them up since the engine was a few degrees retarded. Also, I think the throttle plates aren't open far enough at idle so I need to get a slightly longer screw since the one installed is bottomed out.

[56CAD]

Chevynut, that sounded great!

[chevynut]

Well I've started the 502 a few more times the past month. I put a longer idle screw in the throttle body but don't know for sure where to set it so the IAC motor can work properly. I think I need to set it at the lowest idle I want and let the IAC step it up when it's needed (A/C request, etc.). The engine doesn't seem to want to die after hitting the throttle now like it did in the video.

Also, I tried to do some more checking today to make sure the fans are going to keep the engine cool at idle. The problem is the PC I'm using seems to be screwed up, or the ECU isn't accepting programs for some reason. It worked fine when I started the engine initially, and I checked the ECU program multiple times. However, I pulled the data from the ECU today and the RPM cells, WB parameters, and a bunch of other stuff is screwed up. There were RPM pointers that were over 12,000. So I tried re-loading my program into it and it says it was successful. However, when I pull the data from the ECU again it's still screwed up. So either my computer or communications link is bad or the ECU is bad...or I'm doing it wrong. The computer is constantly giving me runtime errors, and says "not responding" and forces me to shut down the application. I'm going to bet the computer is screwed up so I'll have to find another (the third) one. Until then I'm going to assume the ECU is ok.

One other thing that has me concerned is the PS pump. It's brand new, and has never been run until I started the engine. When I had it off to machine and install the AN10 inlet fitting I noticed that something rattled inside. I thought it was normal so I installed it. With the engine idling, I tried to turn the steering shaft and I had no assist. The fluid level hasn't gone down in the reservoir either so the rack isn't filling up and I'm afraid the pump isn't pumping at all. It should be full of fluid since the reservoir is above it but I don't know why it doesn't seem to want to bleed the system. I figured I'd have to add fluid. Any ideas?

[chevynut]

Spent some time looking at the C950 manual tonight and found this:

"Opening a File into the Computer – To open a file into the computer perform the following steps:
1) Select “File” and “Open Data from Disk”
2) Select the file you want to open, either from the hard drive or a disk. (This is explained in “Step-by-Step Initial Startup”).
3) Hit “Enter” or click on “Ok”
4) The file is now in the computer.

Sending a File to the ECU – To send a file to the ECU perform the following steps:
1) Open a file as described above. Do NOT go to any of the other areas in the software, as this will retrieve and corrupt
the data that you just opened.
2) Make sure the ignition is on. After the file is opened, immediately go to “File” and “Send ECU Data”. It will take about one
minute to send the data. When the hourglass changes back to your mouse pointer, the file has been sent."

What I've been doing is loading my maps into the computer, then opening them up to make sure they got loaded correctly, and THEN sending them to the ECU. Apparently that's corrupting them per the warning above. I found out the best way to modify the maps and other info is to do it directly on the ECU with it turned on, then saving the information in a file when done. I've been doing it the other way around....modifying a map, then sending it to the ECU. Either way works as long as you follow the instructions for loading the file.

So I'll give it another try tomorrow and see if that fixes the problems I'm having.

I also found out that there's a IAC position readout in the fuel map engine data area. On a C950 there are 255 steps from closed to full open, and each 2.55 steps is 1% open. You're supposed to adjust the idle screw such that the IAC is about 3-5% open or about 8-13 steps. This isn't explicitly stated in the manual but I found it on some Holley forums. Hopefully this addresses another issue.

Still not sure what to do about the PS pump. I don't want to remove it until I can do some kind of testing. Maybe it needs to be primed?

[55 Rescue Dog]

Of course the pump needs to be primed. I would be pulling off a line, and try finding a way to spin the pump with the motor off, to test, and prime. It can't pump air, and I would assume it is being turned in the correct direction. Do you kinda miss the good ole carburetor yet?

[chevynut]

Of course the pump needs to be primed. I would be pulling off a line, and try finding a way to spin the pump with the motor off, to test, and prime. It can't pump air, and I would assume it is being turned in the correct direction.

The reservoir is above the pump so the pump should be getting fluid. Why would you have to prime it when gravity takes the fluid into the pump? Today I turned the spindles left and right stop to stop several times with the engine off and got a little air out of the system and the fluid level dropped maybe 1/2" in the reservoir as the rack filled up. I ran the engine again and cycled the steering lock to lock, but still have no power assist. I'm beginning to think I have a defective pump, especially because of that rattling sound in it before I mounted it. What could that be? Is there some way I could have an air pocket in the pump, and if so how do I eliminate it?

Do you kinda miss the good ole carburetor yet?

Not a chance . I like messing with the EFI and being able to see everything the engine is doing on the PC, I'd never put one of those POS carbs on my engine unless it was the last resort.

That said, I'm still having issues with data transfer. I re-loaded the program I've been using and it started dumping way too much fuel and spewing black smoke out of the exhaust. It wouldn't even start without the throttle halfway open. So I re-loaded the Holley 502 program and it runs okay again at idle. So something apparently got corrupted in the map I put together that ran fine before. A neighbor is going to give me another XP laptop to try and hopefully that fixes the data transfer problems.

[NickP]

I still have an old Dell XP unit if you need it.