S1 Project car - part 2 - the continuation

[Lotusfab]

Practical classics stand at the NEC. The end of a year of publicity for the S1. 

Thought I’d better fix the door shut issue before the show!

[JustinB]

What a beauty

[Lotusfab]

23 hours ago, JustinB said:

What a beauty

Thanks mate.

[Lotusfab]

Classic and Sports car car of the year 2021 joint winner with my Turbo!

[Lotusfab]

Well its about eight years ago I started on this car project. My Turbo is done and I am enjoying driving it. I haven’t done much on the S1 since it was finished, so I have decided to go over all the systems and make sure its as good as it can be.
It all starts tomorrow with the help of Andy on here I shall be changing the timing belt and working through everything else. My knowledge has improved a lot over the last eight years, hopefully I can put it to good use. I have upgraded the S1 with a dual 12 volt power source hidden in the glove box. For convenience these days you need an iphone supply and bluetooth music connection. Mine links by radio to my original stereo and speakers.  

Timing belt 

Biggest issue here is how to check the tension. I have three instruments to help. The iphone belt frequency app, a Krikit gauge and a Burroughs gauge. It will be fun to compare them all. I will keep the updates coming on how the car has faired over the last four years. It still looks amazing, but what are the mechanics like? It has always been very reliable, as was proved when we did ten hours of filming for the Bond Vivant on the hotest day of the year, plus 35 degrees! 

 

 

[Lotusfab]

Thanks to Andy, who seemed to do most of the work, the timing belt has been replaced! We were able to do all of it without raising the car. The S1 has much better access than the Turbo and so the job is easier. We drained about half the coolant so we could get the water pipe off, which prevents belt removal. It took about 5 hrs, but if you did it all the time it would be much quicker. The biggest delay was caused by an error in the S1 manual. The locking pin hole is next to the central bolt, under a washer. When we couldn’t find it in the manual location it caused the delay whilst we thought about it. The hole was covered by a washer. Once we got the washer off we found the hole. We weren't able to insert the pin, so we did what you aren't supposed to and took the whole tensioner off. We then cleaned it all, checked the bearing, replaced the piston with a better one I had, compressed it with a clamp, put the pin back in and replaced it on the engine. Heres a pic of the location hole! It will save someone a lot of hassle.

We measured the belt tension using the three methods. The gates app gave 114Hz at 30 BTDC. The Krikit 50 lbs and the Burroughs 75 lbs. The problem here is the belt is trapezoidal and not round tooth. The readings from a correct Turbo were 85HZ with a round tooth belt. Not having a comparison we couldn’t use the frequency. We put the new belt on and found no matter what tension we used the KriKit read 50 lbs. All I can assume is the belt run is too short to measure the tension using the krikit. So that left the Burroughs. It hasn’t been calibrated. We set the tension to 87 lbs using the gauge. To me it feels tight, unable to get 90 degrees. I may actually bin these methods in the future and just use feel. I shall be taking the car to a specialist and getting them to check the tension. If they say its too tight I shall use feel only in the future.

This job is so much easier and quicker with two people, so get a mate to help when doing it!

I have found lots of other things I need to do on the car. The Exhaust cam cover is leaking again! I have resealed it so many times. It lasts for about 6 months and then fails, a very common problem on these cars.This time I am going to try a Gary Kemp rubber gasket. 
The car has done about 1200 miles in 4 years since the resto was finished. I have a long list of jobs to do over the next month then it should be tip top again.

Andy spotted a dent in the top fuel hose caused by it resting on a carb screw. I will now have to replace the entire hose. Still the engine looks ok considering I haven't done much to it and it sounds great! I used Millers 20/50 synthetic racing oil. My car doesn’t like this. I had it in the Turbo as well its very good quality by in my opinion these cars like thicker oil. After switching to castrol 10W60 racing oil in the Turbo and finding it runs very well I am going to switch to 10W60 in the S1.

[910Esprit]

I thought the book reading, in Hz, for a fixed tensioner/round belt was 100 - 110Hz?   So when you say a "correct turbo at 85Hz" are you suggesting the Hz reading on the phone is inaccurate?   You could calibrate that against a 'tuned' guitar, or similar.

You could also calibrate the Burroughs gauge by  cutting the old belt and suspending a known weight from it to compare the reading on the gauge.

Mines currently running at 110-114Hz (Semi Auto/Trap belt).  The other check I like to do is ensure that the spring in the tensioner has almost, but not quite, 'bottomed out' with the engine hot.

Many years ago Pete Musgove told me another method to informally measure belt tension -  It was to compress the tensioner to its limit and then set the belt by the total deflection in the longest run  - but I cant remember the figure suggested!

 

[Lotusfab]

8 hours ago, 910Esprit said:

I thought the book reading, in Hz, for a fixed tensioner/round belt was 100 - 110Hz?   So when you say a "correct turbo at 85Hz" are you suggesting the Hz reading on the phone is inaccurate?   You could calibrate that against a 'tuned' guitar, or similar.

You could also calibrate the Burroughs gauge by  cutting the old belt and suspending a known weight from it to compare the reading on the gauge.

Mines currently running at 110-114Hz (Semi Auto/Trap belt).  The other check I like to do is ensure that the spring in the tensioner has almost, but not quite, 'bottomed out' with the engine hot.

Many years ago Pete Musgove told me another method to informally measure belt tension -  It was to compress the tensioner to its limit and then set the belt by the total deflection in the longest run  - but I cant remember the figure suggested!

 

I recently measured the frequency for a brand new fixed belt tensioner with round tooth at 85 Hz in about 15 degrees C using the gates bicycle app at 30 degrees before TDC. I set my newly built engine some time ago to 100 Hz. It whined slightly when hot. It took it to a specialist who confirmed it was tight. Conclusion 85 Hz on the app is probably correct. We set out to calibrate the Burroughs gauge but the spring balance only went to 20 kg. I measured the frequency on the S1 at 114 HZ, before replacing. I don’t know whether the app frequency is correct, I assumed it was.

[Lotusfab]

As my obsession with these cars continues I have put together a to do list. These are the things I consider are worth doing after four years plus the more regular maintenance items.

I have a seepage from the rear cylinder head core plug. I will replace it and use loctite 574 to seal.

the corner coolant pipe needs securing

I will remove and service each calliper and grease with a fluid change, as required. Also grease all wheel bearings and adjust.

I will change the clutch fluid and adjust back to spec

I rebuilt the existing steering column but as new later design ones are available I have bought two! I shall fit one to the turbo and one to the S1.

The camshaft cover has been resealed about three times in four years. I used the original gasket. The last time I took so much care and it only lasted about 6 months. This time I am fitting a Gary Kemp rubber gasket. I will also correct any flaws in the castings which may be causing the issue.

I am also planing to fit a bilge air fan as a back up cooling aid. My S1 has lots of upgrades, some of the earlier ones don't have. It has an airscoop  for the air box that faces forward under the body and sucks in cool air for the carbs, it has bespoke triple kenlow fans and an oil cooler. It did 10 hours at 35 degrees whilst filming for the Bond vivant. I must have started the engine about 40 times during the day and there were no fuel vaporisation problems. I have decided to go one step further and fit a blower to pump cool air to the top of the engine bay.
Hopefully I will have this all completed in the next few weeks, Especially now Andy has offered some more help even after the belt change. Thanks Andy!

 

[Lotusfab]

Slowly working through the jobs. I Have a power spark electronic ignition. The S1 has a resistive wire and ballast coil. I was going to install Andy’s diode starter mod as I have upgraded to a high torque starter, only trouble is I had already used the yellow and white starter wire to power the power spark. I built it all quite quickly so I decided to measure the voltage and resistances. I discovered 7v across the coil. I was using this to power the module which requires 12 v. But where do I find and unfused 12 V supply in the engine bay? Answer purple and white fuel shutoff solenoid. I tested it with a direct 12 v supply. It runs slightly better than before on acceleration! Once I have modified the wiring I will be able to use the yellow and white wire for the increased 12 v starter boost. With iridium spark plugs it should spark like the sun on start up! 
i have found a lot of degraded fuel hoses so will be replacing them all. I also found the otter switch was was leaking! I forgot this is redundant on my car as I have an adjustable inline thermostat in the radiator. I don't wish to trust wire locked otter switches so will switch out the pipe for a new one without a otter switch hole.

[drdoom]

What's the idea with Andy's diode mod?

 

[910Esprit]

To use the 12v starter feed to bypass the ballast resistor on cranking, with the diode to avoid the coil then feeding back to the starter in running mode?    

[Lotusfab]

2 hours ago, drdoom said:

What's the idea with Andy's diode mod?

 

 What Steve said.

My Turbo has this and it really springs to life quickly on start. I am hoping the S1 will be the same. 

I have finally decided to switch from 20W50 to 10w60 full synthetic. I did this on the Turbo and it really likes the oil. Its smoother on start and just seems to like it. There is also more oil pressure when hot. 

[Lotusfab]

I have ordered new Dellorto carb filters and banjo washers as I will be replacing some of the fuel line with parts from Eurocarb, can’t trust some of the other suppliers - there a lot of rubbish out there!

[omegaman]

10 minutes ago, Lotusfab said:

I have ordered new Dellorto carb filters and banjo washers as I will be replacing some of the fuel line with parts from Eurocarb, can’t trust some of the other suppliers - there a lot of rubbish out there!

I bought a set from there and the filters don't fit. Couldn't see any original banjo fittings on there, just reproduction ones. 

[drdoom]

You'd already know this Fabian, but do hang onto outgoing parts whenever putting replacements into service. Sometimes one bit won't be suitable, as @omegaman advises.

Interesting take on the diode, I'd thought it was SOP for cars to bypass the ballast while cranking.

Cheers

[Lotusfab]

10 hours ago, omegaman said:

I bought a set from there and the filters don't fit. Couldn't see any original banjo fittings on there, just reproduction ones. 

Thats unusual I hope they do fit! I will find out soon and report back

7 hours ago, drdoom said:

You'd already know this Fabian, but do hang onto outgoing parts whenever putting replacements into service. Sometimes one bit won't be suitable, as @omegaman advises.

Interesting take on the diode, I'd thought it was SOP for cars to bypass the ballast while cranking.

Cheers

Yep your correct, I have learned that lesson only too well over the past 8 years of restoring two cars.

[Lotusfab]

Another hards days work. Takes ages to change the gearbox oil as all the boot boards and carpet have to come out. I changed the engine oil to mobile one 10W60 fully synthetic. Seems to like it. Far more oil pressure when really hot.

I drained the cooling system and replaced the rear cylinder core plug. Went in quite easy and I used Loctite sealant. I have changed the cooling system so the otter switch is redundant. I will be getting rid of wire locked otter switch as it was leaking and a potential failure point. Nearly got the car up to speed. Just the ignition system, fuel pipes and bilge blower left to install! 

[LOTUSMAN33]

Good work Fabian, keep us posted on how the oil performs as I will follow your lead if it’s good. I have used Mobil 1 on other cars with happy results so sounds like a winner. 👍🏻

[drdoom]

On oil pressure, Fabian, what specific numbers are you seeing?

[Lotusfab]

15 hours ago, drdoom said:

On oil pressure, Fabian, what specific numbers are you seeing?

I have a Veglia display so no numbers. With the thicker oil the needle sits higher when its warm.

Fitted the new carb filters from Eurocarb. The washers and filters all fitted perfectly.

[Lotusfab]

Top fuel hose repaired…trying to find a satisfactory method of securing the rest of the hose and in-line filter to the chassis!

I have it on good authority Tim Engle, who is an expert on oils and lotsbof other things, picked this oil as the best for the car!

[JonSE]

What mod did you do in order to be able to delete the otter switch?

[Lotusfab]

15 hours ago, JonSE said:

What mod did you do in order to be able to delete the otter switch?

I have a thermostatic sensor in the radiator outlet and a temperature selector, so you can set whatever you want. I have decided to use the otter switch connections for a manual overide. I plan to add a bilge blower, so all four fans (three Kenlows on the rad) will switch on when you hit it.

Lotusbits make all the pipe now bespoke if required and in house. Easy for them to knock up a pipe without the Otter switch bit!

[Lotusfab]

So wiring complete with extra start voltage boost! Should finish the fuel line tomorrow and then will be drivable. Final piece of the puzzle bilge blower and temperature testing. my previously restored engine after four years of use in all weathers.