Project BMP

Page 20


569 hours later.....

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It seems like I have been working on this project for a lot longer than just 4 months.  When I started it the temperature outside was in the triple digits hovering close to 120 degrees, now the mornings are nearly 70 degrees cooler!  I actually am thankful for the cooler temps, it's easier to keep warm while fabrication anyway. 

I managed to overcome my electrical gremlins with some help from the guys in the club.  Basically everything appeared to be properly hooked up and running but the motor would not fire.  The mistake I made was missing the fact that the distributor and injectors were only showing 5v.  I figured voltage was voltage but they need to see 12v.  I spent 2 nights working thru the harness and with no luck, but once my friend Mark mentioned the injectors should be getting 12v I found the problem within minutes.  The blue/black wire off of the main relay went to the fuel pump relay then stopped, I must have missed a splice because it should go down into the harness and eventually provides power to nearly everything under the hood on the motor.  The motor fired right up after I spliced in a new power feed line. 

Next up was figuring out how to wire in my gauges.  I purchased an Autometer tach, water temp, oil pressure and voltmeter gauges.  First I ran two fused power leads (one for the gauges and one for the gauge lights) and a ground line to the center of the dash were the gauges will eventually reside.  For the tach signal I used the brown wire that came off the stock instrument cluster.


The gauges I purchased were considered electrical as opposed to mechanical.  Electrical gauges have remote senders so you typically just run one wire from the sender to the gauge (and power, ground and light power).  I had two senders to install, the first was for the water temperature gauge.  The new sender was going to be installed in place of an unused thermal fuse located on the passenger side of the thermostat housing.  Since the gauge senders have NPT threads and the Suzuki motor ports have BSP (basically metric pipe threads) I needed some adapters.  I ended up finding a package of 6 assorted adapters at the local Autozone for $5.  They were made by Sunpro, P/N CP7573 and included a 1/8-28 BSP to 1/8NPT adapter (used above), an M10 x 1.0, M12 x 1.0, M14 x 1.5 and M16 x 1.5 to 1/8NPT adapters.

The second sender was for the oil pressure gauge.  I located a plugged port on the oil pump housing and unscrewed the plug.  I forget which adapter fit it but I just matched up the threads with the plug.

I finished off the brake lines on the front axle housing.  Pretty much the same drill as the rear axle, hard lines where there is no movement and soft lines bridging the gap between components that move.  I plan on using Dot 5 brake fluid for the simple fact it doesn't act as a paint stripper if it gets spilled.  In my experience spray paint bubbles almost immediately when it comes in contact with Dot 3 or 4 brake fluid.  Dot 5 is pretty expensive, roughly $20 a quart but I found my system only used roughly 3/4 of a quart, so after bleeding it looks like one bottle will be enough.

The last big project was mounting the steering ram.  I centered the ram on the axle housing and welded the bottom half of the mounting clamps on.  I also modified the top half of the mounting clamps buy cutting about 3/8" off the top creating a flat mounting surface.  I then drilled and tapped two 10-32 holes in each piece.  Next an aluminum plate was fabricated with a hole pattern so it would span the two cylinder clamps.  The reason for these modifications was to created a flat spot for the bump stops to land on.  From my experience with bump stops, any irregular surface or landing zone smaller than the bump stop tends to chew up the bump stops in short order.

Once the ram was mounted I started adding fluid to the steering system.  I am using Valvoline synthetic power steering fluid again and filled the system in the following order:

Ram ports (pour in and tilt ram until no more bubbles are seen and ports are full).

Attach ram hi-pressure hoses, fill hoses with fluid then attach to valve.

Next I removed the top line from the cooler and filled it to the top.

Replaced the power steering filter and filled it with fluid before re-installing.

Lastly filled the reservoir.

Next I actuated the steering valve, this caused the internal pump to build pressure and I found I needed to tighten most of the fittings again.  Space was pretty tight so getting a wrench on some of the fittings a chore.  For reference the JIC fittings I used are supposed to be snugged, then an additional 1/4 turn to the fitting is considered a good start.  Once there were no more leaks I actuated the system with the steering wheel another 20 times to circulate some fluid in the system.  The last thing I did was start up the motor after making sure my reservoir was full, then with the motor running I ran the steering back and forth for a while to work any air bubbles out of the system. I did replace the old AGR power steering pump with a unit from PSC (TC Style #1200X) .  I wasn't happy with the AGR unit I purchased a while back on my last project.  It was very noisy from the moment I started using it.  The new unit is built off the same style Saginaw pump.

Next I'll cover the fittings I used (it might help someone).  The new ram used SAE -6 O-ring fittings.  The two ports that fed the ram use 3/4 Boss O-ring to -6 (JIC) adapters, same for the hi-pressure input.  The low pressure return line uses a 3/4 boss o-ring to -8 adapter.  It's important to keep the hose sizes as large as possible on the return side to avoid any flow restrictions and eliminate a potential source for heat build up.  A good general rule is to go up a hose size after every component on the low pressure side, so for example -6 from the valve to cooler, -8 from cooler to filter and then -10 from filter to reservoir. 

In my case my cooler (shown above) was -8 on both ends so I used -8 hose between the valve and cooler and cooler to filter.  From the filter I used a 1/4 NPT to -10 JIC adapter and then -10 hose to the reservoir.  -10 hose is also used from the reservoir to pump.  You should also try and keep the low pressure lines under 24" in length, shorter the better to avoid pressure drops.  Lastly the feed line from the remote reservoir to pump should be as big as possible. never go smaller than what the pump fitting is (in my case it is a -10).

By Sunday I had enough of the buggy done to take it for its first test drive. Jack and Scott dropped by and brought over Mark's nitrogen tank so we could charge the air shocks.  I was unable to get the front shocks fully extended due to the hydro lines being a little too short so I'll have to add some more nitrogen later when I can disconnect the ram temporarily.  I ended up charging the rear shocks to 200psi and the fronts to 225psi.


Once we had the differentials full of oil and a few last minute things tightened down it was time for the buggy to roll out of the garage under its own power.  Here's some video of the occasion.

After the test run I made a list of the things I needed to change/complete.  Right at the top is an exhaust system (it was loud!).  The brakes are nearly non-existent, the pedal is firm but there doesn't seem to be much stopping power, this needs attention.  I also need a front driveshaft, gauges installed, move the gas pedal over a bit (too close to the brake pedal) and a few of the hard brake lines are still seeping so I may need to re-flare the ends.

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