520R SV build has commenced

[CBuff]

Original build slot was June. Then sept. Now November. Maybe.  Apparently caterham is pushing all Duratec models due to some supply issue. I don’t have space to assemble so it’s a rolling chassis.  Holding onto hope that next summer I’ll be on the road. Fingers crossed. 

[JohnCh]

Sorry to hear about the delays.  Although given it's a rolling chassis, you may skip all the other frustration that comes with buying a Caterham these days like missing parts, things that don't fit without excessive and creative swearing, instructions optimized to make things look simple rather than actually explain what to do, etc  

[kayentaskier]

I thought the loop hole for shipping rolling chassis was closed. Did I miss something?

[CBuff]

Sorry, I misspoke. Factory assembled. Engine and transmission will be installed by a third party here in the states.

[JohnCh]

I'm approaching the home stretch and preparing for the first attempt at starting the engine.  That means sorting out the upper radiator hose, hooking up the AiM, and finishing a number of other minor jobs.

 

First, the upper radiator hose.  The factory supplies a complex, molded hose that snakes under the intake and around the belt tensioner.  Unfortunately, it won't work with my car due to changes required by the Jenveys; underslung throttle linkage and different belt tensioner.  My initial hope was that cutting off the 90 deg elbow section at the back and replacing it with a longer elbow would create clearance for the throttle linkage, but that moved other bends forward, creating new interference problems.  To resolve these, I opted for a Gates Vulco-Flex which is a convoluted hose that can make the gentle transitions around everything until it reaches an elbow at the back.  The only issue was proximity to the tensioner pulley.  There was only 1/4" clearance which would likely quickly go to 0" when the car was underway.  A simple double bracket eliminates that risk.  The lower portion clamps to a chassis diagonal and the upper part wraps around the hose to prevent it from moving closer to the tensioner.  
 

 

 

 

Next was finishing the wiring harness for the AiM, programming it, then setting up the MBE for CAN.  Unfortunately, not everything is working correctly at this stage, but that was expected.  I don't (yet) have the calibration data for the oil temp and oil pressure sensors, the tach is reading very high (7000rpm when cranking), and I noticed today the odometer shows I've already driven the car 3 miles despite the fact it doesn't run.  On the positive front, the warning lights for turn signals/hazards and high beams work correctly as does the battery voltage readout.  

 

 

The AiM has a lot of sensors in its calibration library, including a Variohm oil pressure sensor.  Because the current Caterhams use a Variohm sensor, I selected that absent of the actual sensor data.  It's clearly not correct, showing -33psi when engine is off and reaching over 50psi when cranking.  The positive is that the engine turns over and it appears to have oil pressure. 
 

I've been waiting to install the silencer until the passenger seat is in, but the seat runners have been delayed for a while.  First, because they were out of stock, and now because customs has been sitting on them in Memphis for over 2 weeks.  I was initially told not to worry about clearance issues between the primaries and side skin -- plenty of room to compensate for the 13mm taller engine -- and that seemed correct.  Until today.  With the springs in place to connect the collector and primaries, the clearance decreased to the point that it makes me a bit nervous: 2.5mm-3.7mm over the top two primaries.  

 

The Westfield has the same engine mounts as the Caterham.  Starting it from cold to see how much the engine and the primaries moved during the lumpy idle phase and when the throttle was blipped showed virtually no movement.  I'm hoping this means it will be okay.  Unfortunately creating more clearance at this stage is potentially a lot of work as the dry sump tank is in the way of removing #1 (the one with the least clearance) and that is now full of break-in oil.  I'll give this one additional thought.

 

-John

[JohnCh]

I did a number of things over the past week in anticipation of starting the engine this weekend.  Unfortunately, that attempt will need to wait a few days.  It turns out I forgot to order the special Loctite recommended to seal the aluminum plugs that block the unused injector ports in the head.  On the positive front, I was able to speak to Variohm this week to get the calibration specs for the factory oil pressure sensor.  They were very nice, very helpful people.  With that information programmed into the AiM, it displayed the expected 0 psi with the engine off and reached about 46 psi while cranking.  Having oil pressure at this stage was a relief.

 

Next was prepping the fuel system.   Which didn’t work.   At all.  After checking fuses and confirming there was no continuity between the pump and fuse box -- huh?? -- it dawned on me the fuel cutoff switch must have tripped.  With that reset, the newly arrived capacitance fuel sensor worked, and the fuel pump kicked in.  Aside from a slight leak at the pressure gauge, things were tight, and pressure was set to spec.  Spark plugs -- which are something else I forgot to order earlier -- were gapped and installed, coolant was added and bled, throttle butterflies were set to 0.05mm and the TPS adjusted to 0.37v…and then I discovered the Loctite issue.  Oh well.

 

 

With time on my hands, I cleaned up some of the wiring under the dash (not that you can tell), added a Deutsch connector for power and ground for the AiM, and also did final prints for the new fuse box, oil filler cap, and air horn extensions.  I'll save photos of the fuse box for when I do that install next weekend.

 

 

 

 

 

-John

[Alex-Ks1]

just remember,,, complexity is the mother of all screw ups , simple always works

 

[JohnCh]

I think it's a little late to tell me that

 

-John

[MV8]

Which loctite retaining compound did they recommend?

[JohnCh]

Loctite 648.  I have 680, which is also used for tight fitting slip joints, but after looking into the specs, the 648 has much higher breakaway strength and that strength is not diminished to the same degree with heat (100C).  Given these plugs are in the head which can get hot, and coming loose can lead to bonnet damage, it seemed a prudent delay.

 

-John

[windsurfer]

1 hour ago, Alex-Ks1 said:

just remember,,, complexity is the mother of all screw ups , simple always works

 

This is probably true, except if you are an engineer. Then you design things until they are over the top and once you get there, you work (try) to make it more simple without sacrifing anything. :-) 

 

 

[Alex-Ks1]

Most engineers forgot the pointy end of the screw driver goes to the screw.

Example ,,, simple has few letters , complexity has a lot ,,,, simple isn't it 

 

[JohnCh]

I'm a big believer in the simplest solution that meets the design brief, but that latter point is important.  An old updraft carburetor is a lot simpler than a sophisticated electronic fuel injection system, but there is no question that if the design brief is to maximize power, fuel consumption, and drivability, the more complex EFI solution wins.  If the design brief, however, is to allow the engine to run and make problems easier to diagnose, then stick with the updraft carb.

 

-John

[Alex-Ks1]

Your correct to a point ,, when this EFI crap brakes down then what ? Take  a every day car on the road ,if it brakes down the repair cost is so high ,I have personally known people that just let them there ,  I also know 2 mechanics that left the ford dealership where I live , they are sick and tired of seeing the crap that comes out of the factory's . For fuel economy it may be just great , I don't care if gas goes to 10$ a gal , if you need it your going to pay the price   , 

[Vovchandr]

13 minutes ago, Alex-Ks1 said:

Your correct to a point ,, when this EFI crap brakes down then what ? Take  a every day car on the road ,if it brakes down the repair cost is so high ,I have personally known people that just let them there ,  I also know 2 mechanics that left the ford dealership where I live , they are sick and tired of seeing the crap that comes out of the factory's . For fuel economy it may be just great , I don't care if gas goes to 10$ a gal , if you need it your going to pay the price   , 

 

When "EFI crap brakes [sic] down" you fix it same way you fix "mechanical crap" when it brakes [sic] down. 

 

Its okay to not like it, but its not inherently worse to be using modern technology in vehicles. As far as basic drivetrain reliability modern cars are most efficient and longest lasting than ever. 

 

I for one don't want to be hand crank starting my daily driver because I'm afraid of a starter mechanism and a relay and I like to enjoy things like a digital radio and GPS navigation instead of a map to get places.

 

 

[JohnCh]

My point was the design brief is tightly coupled with acceptable complexity.   If the design brief contains a principle that supportability must continue for X years, then that would factor into the decision.  Bottom line: know what you are trying to accomplish, know the constraints, and know how you value different things that are part of the process and outcome.  That helps optimize the solution for you. 

 

-John

[MV8]

John's verbal judo is strong. He had me at "updraft".

 

Actually I do have an updraft on my antique iron tiller. Works great, but this is not a race. Carbs are great, but not for everybody most people.

[JohnCh]

24 minutes ago, MV8 said:

John's verbal judo is strong.

 

I'm sure @Crocwill be along soon to correct that misperception

 

-John

[MV8]

Edited May 16, 2023 by MV8

[JohnCh]

I had a few minutes after eating lunch so decided to see what happens when I pressed the starter toggle.

 

 

I turned it off quickly to avoid running the engine at low rpm before the cam break-in procedure.  Before doing so, however, I glanced at the AiM and noticed the tach was way off and the check engine light was on, but the beast started immediately and had a nice idle, so I'll call that a win for now.  Next step is buying some support time from SBD to go over some open questions and also get some guidance on identifying what triggered the CEL.

 

-John