Ram Jet 350 to H55 install-73 FJ40

[DomSmith]

Ok I really am going to finish this...

Now that the cooling system was finished up I filled the radiator with coolant. I used the stock radiator as I had with the previous 350 and hoped it would work well. I knew that if I needed to I would eventually put an aluminum radiator like Cirbo is doing.

Once I had the coolant filled I decided I would add all the remaining fluids. The oil had been filled before priming the motor and as mentioned before I had drained the tranny and transfer with plans of dropping them. Since that wasn't necessary I just pumped them full of gear oil again. Assured the power steering fluid was full and rechecked the oil. Next was re-installing the starter, finalizing the batteries, fitting a throttle cable and confirming the wiring was correct.

 

[DomSmith]

Once the fluids were all topped off I needed to bolt the starter back on. As it turns out the fitment was a little different from my last motor so I had to remove the clutch cover and grind away again. I had to remove more of the same areas as I had when I added the H55 to my old motor. A minor problem I didn't anticipate but easily rectified.

After the starter was bolted back in place I bolted the clutch slave and custom bracket back in place. Then I looked at the photos I took of how all the wiring was hooked up to the starter on my old motor and replicated that on the starter again.

 

[DomSmith]

With the previous motor both batteries were on the passenger side and blocked the exhaust manifold and oil dipstick so I re-tightened the manifold bolts and assured the dipstick sleeve was installed correctly one more time. Then I positioned the battery trays in the engine bay to see what kind of clearance I had. Once I was satisfied it would have sufficient clearance I bolted the trays in and re-connected the batteries.

Here's the battery fitment...

With the idler pulley in place it would work as before but I realized I would need to move one battery once I decided to put the York compressor back in for the OBA setup.

 

[DomSmith]

Once the batteries were in place I needed to attach the throttle cable. I already had a different than stock cable from my previous FI setup and determined it would be just fine for this application. It was long enough and had the correct end attachment, I just needed to fab up a bracket to the Ram Jet.

I pulled a few throttle bracket parts out that I had saved from another project (I knew I held onto these all those years for a reason! ) and cut them down to fit. At first I was afraid they would look really bad but they worked out just fine.

First I pushed the cable through the large opening on the throttle bracket mounted to the intake (it was too big to slide through the smaller hole near the bottom)...no jokes here please. I then bolted the cable attachment to an angle bracket that I drilled two holes in...

Then matched up the slotted backside bracket that this 90 degree bracket would bolt to and allow for proper adjustment...

And finally, the finished product. Not hot rod show worthy but works like a charm.

 

[DomSmith]

Now that the throttle cable was in place I double checked what I had on my list before startup. Cooling system in place, check. Fuel lines in place and tight, check. Batteries and starter hooked up, check. Serpentine belt in place, check. All fluids, check. So after re-checking the wiring and scouring the instructions for anything I was missing I was ready to go. The last step once started would be to follow the instructions on how to set the timing using the computer diagnostic tool. Woo Hoo! Moment of truth...

 

[DomSmith]

She fired right up! At an extremely high RPM, then...


BAM!!!

 

[Poser]

Oh my.....

 

[DomSmith]

Holy !!!

After quickly turning off the motor and swallowing a giant frog in my throat it was time to investigate. With extreme skepticism I looked for the source hoping to find something simple... and inexpensive...


Fortunately the lower radiator hose had blown off the "T" fitting between the radiator and water pump. An easy fix but an absolute nightmare to clean up. The worst part?...

It happened four more times after cleaning up, re-connecting, and re-filling the coolant.

Nightmare!!!

 

[DomSmith]

Here's the link on my question on the subject... https://forum.ih8mud.com/40-55-series-tech/185555-real-time-help-blowing-lower-radiator-hose.html

I tried double clamping it, removing and re-installing, cutting off some of the ends for better fitment.

Not until I started over from scratch on the lower hose setup did I get it to start without bursting in the first 15 seconds.

The real cause then came out...

For some reason the rig was starting up at about 3000 RPM and not slowing down.

 

[DomSmith]

I wasn’t quite sure why the engine wanted to run at such high RPM’s but you can imagine my concern. Especially after having blown so many radiator hoses and filled my driveway with coolant time and time again. To say I was a bit on edge is an understatement. Each time I started the rig it reved at 3000 RPM and sounded like the intake was trying to suck my entire garage in. I didn’t have the courage to let it run for more than about 10 seconds each time. I decided to email someone (I don’t remember who ) that I saw had installed a ramjet and posed the question to them. They agreed that their motor started up at higher RPM’s each time but just for a moment, not even close to 3000 RPM and it immediately settled to idle. They had had none of the initial startup problems I was experiencing.

I scoured the RamJet book again to look for hints at my problem with no results. It seemed like each time I started the rig it would be just a tad lower in RPM each time but not by much. At this rate I would have to start and stop the rig 100+ times for it to get to a level that I could let it run without stressing.

Timing? I was afraid to run the engine long enough to use the diagnostic tool to assure proper timing. I figured I would start it a few more times and see if it would miraculously come down. Then...






PSSSSSSSSSSSSSSSSSSSSSSS!




A huge hiss, the motor died and fuel was spraying everywhere.

 

[DomSmith]

In my infinite wisdom to use high pressure Fuel Injection rated rubber hose jammed onto AN fittings that were bigger than the inner diameter of the hose with questionable "high pressure" hose clamps I had mixed the perfect recipe for disaster.

Looking back now it was as dumb a move as I would make on the project. I had spent countless hours sourcing parts that would save a few bucks... ground down AN fittings to meet my frankenstein specifications... and eroded what integrity the rubber hose had by forcing it on too big of fittings by twisting and pushing and twisting and pushing until my fingers were blue and the hose was deteriorated (unknown to me).

You can see here how the hose is bulging from the large fitting I used for the pressure gauge. This is exactly where the hose ballooned and burst but in reality it could have happened at several locations. All of this because I thought it would be good to use the original metal fuel supply and return lines clipped to the frame connected to my fabulous array of rubber lines mismatched with the wrong sized AN fittings and questionable clamps that could have caused an extensive fire. Did I mention that I am an idiot and these steps should never be replicated?

 

[DomSmith]

Thanking my lucky stars that I had averted certain disaster I took stock of what I had on my hands... a completely unacceptable fuel system that had nearly cost me my beloved ride and maybe more to save a few bucks. It was time for drastic measures. I called my speed shop buddy and asked him where to get stainless fuel lines made locally and I drove over to crownperformance.com. They were very helpful and I had two custom length 3/8" fuel lines made with the proper fittings. Shown below is the return line with a 90 degree that attaches to the fuel pressure regulator.

Inlet (supply side) on the backside of the passenger side fuel rail with new hose...

Return line connected to the fuel pressure regulator on the drivers side...

Because the fuel pump I bought had a built in barb fitting on the outlet side they also made me a very short high pressure rubber hose (about 2" long) that slid over the barb with a high pressure clamp and the AN fitting to attach to the stainless line...

I also had them piece together some connectors to attach a fuel pressure gauge on the fuel rail. There's a kit out there Accel DFI fuel pressure gauge (P/N 74726) but initially I opted to make my own since I already had the gauge and the kit is a little pricey. I later decided to get the kit to troubleshoot a buddies boat and I am not impressed. The gauge is cheap and the fittings are good but certainly not worth the money. It does come with a schraeder valve removal tool which is essential to adding the gauge.

You can see all the parts I had here. From the left is the gauge I previously had along with the fittings (elbow) I pieced together at Crown. The second gauge is the cheaper one from the kit listed above along with the kit elbow (in plastic bag), the black fuel rail fitting, the shraeder valve that was removed, the valve removal tool (from the kit) and the fitting cover.

First you need to remove the cap from the fuel rail fitting and then remove the black fitting. Next use the shraeder valve removal tool to remove the valve from the black fitting and screw it back into the fuel rail.

Next I attached the fittings provided by Crown and screwed in the gauge. It's a tight fit so you may have to attach the gauge and then make the connections to the black fitting. Here it is installed.

 

[DomSmith]

Now that I had resolved the lower radiator hose issue and the fuel line debacle I was ready to tackle what helped these weaknesses show... the over revving engine on startup. I read through the book thinking I must have missed something but I couldn't find anything. I decided to follow the directions in the manual to run a diagnostic check with the small blink code tool (DTC) that came with the engine but was unsuccessful.

After starting the rig several times and shutting it down the RPM's were noticeably lower. Repeat. Lower. Repeat. Lower. Finally it was low enough to leave running and eventually settled at a decent idle.

I have absolutely no idea what the cause was at the time and to this day have no idea. I can tell you that my neighbors didn't like the sound of that 3000 RPM and massive intake noise like a jet engine.

Once the RPM's were at a reasonable level I was able to set the Initial Timing using the DTC. This is done by turning the engine switch off, placing the DTC's test switch to the off position and plugging the tool into the wiring harness. Then start the engine and flip the DTC toggle switch to "on". Now the base timing can be adjusted using a timing light and by turning the distributor. Mine is set to 10 degrees BTDC as recommended in the installation instructions.

Finally she was running...

 

[Cirbo]

Wow... you're scaring me dude....

 

[DomSmith]

Jim I wouldn't sweat it. Maybe try doing the initial timing with the DTC when you first fire it up. If I had it to do over I think I would do that.

 

[DomSmith]

The initial break-in period is described in the instruction manual and consists of first assuring you have good oil pressure, coolant temperature and no leaks. After that it recommends running it under varying loads and speeds for the first 30 miles without wide open throttle or sustained high RPM accelerations. Then run five or six medium throttle accelerations to about 5000 RPM. Then two or three hard throttle accelerations up to 5000 RPM and 55 MPH. Change the oil and filter. The next part is with regards to the first 500 miles and that indicates driving under "normal conditions" without running it to the max RPM of 5800 or extended periods of high load. Change the oil and filter again.

This all sounds good and easy but makes no sense considering the MEFI 4 computer computer has a "green" mode that controls rpm during the break-in period; from start-up to the end of the first hour is 4000 rpm, the second hour is 4500 rpm and the third hour is 5500 rpm.

So I did my best to follow the break-in directions despite the RPM limitations of the computer. After a few days of driving around San Diego I decided to put on some miles with a drive to work in Santa Monica. Besides it was a week before Surf n Turf (2007) and I had to have this baby ready for my first trip to Pismo and I wanted to be sure it would hold up for the trip.

Wow, what a difference with this motor and a 5 speed. but there seemed to be a few oddities I encountered before heading to Pismo...

 

[bigassbike]

I have been following your thread. Nice work. Please tell us about the oddities.

 

[DomSmith]

I was very impressed with how smooth the Ramjet started and idled, as well as the throttle response and driveability. On initial start-up the engine roars to life immediately and jumps to about 1000-1200 RPM for a second or two and settles back down to 700 RPM. This happens each time I start it and has nothing to do with tapping the gas pedal or not. The throttle response is crisp and easy with fluid range and is much smoother than the TBI setup I had before.

But there were two issues that I didn't understand. First I really wasn't THAT impressed with the power increase. This baby has 350 HP and I was certain I would be feeling a huge difference. I tried not to be too disappointed after all this work and I was happy to have it finished for SnT. Second the rev limiter was cutting out at 4000 RPM after several hours of clock time and several hundred miles.

Oh well, I had a few other issues to attend to before the trip. I had not yet determined what to do for the air cleaner assembly and the issue of no place for the IAT sensor as mentioned in post #35 so I just stuck with the assembly as it comes from GM (clamped straight to the throttle body) and zip tied the sensor near the air cleaner. (This has since been changed twice).

I also found it a little difficult to source the right breathers for the valve covers. They were different from my other motor's valve cover holes and it seemed to be odd-ball for off the shelf stuff. I eventually went to see a buddy who would let me unpackage a few and plug them right in before I bought them. I also found several people who insisted I needed a PVC valve setup. I found out that many many people (even the local speed shop and hot rod shop) don't have a clue about these motors. I had to rely on my documentation many times.

With no time to resolve the rev-limiter issue I loaded up the ride and headed North...

 

[DomSmith]

Thanks bigassbike. It's a little harder to be motivated to post up a year after it's complete. I forgot how much work it is. The H55 thread was easier because I posted up at night during the process. Figured I better get this done before the next SnT!

I apologize for it being hodge podged and a little out of order... it's hard to remember it all!

 

[DomSmith]

My First Surf N Turf...

So here are a couple of pics from SnT 2007. We arrived very late Friday night and had no idea what to expect. We got pulled over by the cops after blowing a headlight fuse which was good because we were going the wrong way trying to find the beach anyway. After being pointed in the right direction we set up the tent and had a great weekend...



Camping next to some new SoCal friends...

The Sign...

A little vino never hurt anybody...

The Ramjet was great in the sand but some high RPM's and some more power would have been nice. That was first on my list when we got back home...