S1 Project car - part 2 - the continuation

[Lotusfab]

Did you get up to 70mph?

[Paul Coleman]

Yes. At 110mph the rubber trim starts to come off the front bumper!

Those rubber washers are there to stop the vibrations from the engine making the fuel froth. Have a look at the Hammil book.

[Lotusfab]

Ha ha, better glue my bumper rubber down! 

[Lotusfab]

Tuning with colourtune,

Mmmmm. Have given this a go. Adjusted the throttle linkage as per the manual. Started the car and warmed it up. The lotus manual recommends 2 turns out in the mixture screws. Car starts easily. Then warmed up and installed the colourtune plug. The 907 not the best engine for this as the plug recess is so deep. Has anyone seen it turn blue? I tried every position of mixture screw setting. Almost impossible to work out what colour it is but to me it doesnt seem possible to get blue! Any ideas, before I strip the carbs and rebuild them myself?

Edited September 22, 2015 by Lotusfab

[jonroberts]

Fabian - on the mixture setting, try going out to 4-5 turns and see if you get a yellow flame. Then screw it in slowly (half a turn at a time, leaving at least 15 seconds between checking the Colortune) and it should change to blue at some point.  All things being correct, all cylinders should be within 1/4 to 1/2 turn difference.

[Lotusfab]

Hi Jon,

Couldnt get blue. Was thinking of checking float heights. 27 mm from edge to top of fuel level and 15 mm when setting tab and holding float in verticle plane? Still need to balance the carbs with the carbtune then will try your method. Yesterday all I achieved was burnt fingers! The colour tune plug needs to be bigger!

Edited September 23, 2015 by Lotusfab

[jonwat]

I found a mirror to be a big help when looking at the plug. 

[Lotusfab]

Thanks I'll try that, the wifes makeup mirror is easily available now shes out,  just have to clean the grease off and return it before she gets back!

[jonwat]

Buy her a new one you tight git.

I used to undo the mixture screw until I could see the yellow flame then slowly screw it back in until the yellow disappeared & that was it.

[Lotusfab]

??? . Well have checked the float heights these were spot on. Managed to balance the carbs. Then got three of the Cylinders done before the coolant decided to dump through the expansion overflow. The cap is a very poor so will get a new one and hope this fixes the problem. If not might need a new head gasket! If this is the case might as well dismantle and check the whole engine again!

Edited September 23, 2015 by Lotusfab

[Lotusfab]

The radiator seems cool, think there might be an air lock? Could this cause the coolant to empty?

[Lotusfab]

Refilled coolant. Hopefully have a new original expansion tank cap coming tomorrow! Did some more tuning. Ignition set to 10 BTDC. Still getting spitbacks which I cant seem to eliminate by adjusting mixture? Has anyone got any tips. The carbs are balanced using the carbtune. All cylinders are spitting back randomly? This should be the easy bit!

[jonroberts]

Sounds like its still a bit weak. Unscrew (richen) the mixture screws one at a time a quarter to half a turn and see if that improves it.

[Lotusfab]

Thanks Jon, will try that. Also will " burp the coolant system" , just incase theres an air lock. Have picked up a brand new expansion tank cap from Bell and Coville. Came from Lotus its the last original S1 Cap. Interestingly its rated at 10 PSI ! Hope ipts a better fit. 

Edited September 24, 2015 by Lotusfab

[Lotusfab]

What a difference a day can make! Picked up the only brand new S1 original expansion tank cap from Bell and Coville direct from Lotus £7!!! only took a day to arrive. Its the only new S1 Esprit cap left in the UK Its nothing like the one I had. Its rated at 10PSI and fits tightly. Also it can only be removed in two stages. Burped the coolant and fitted the new cap. Run it up and no leaks! Managed to tune to almost no spitting by making the mixture richer but noticed when there is an occasional spit its through the throttle linkage! Will have to strip and rebuild the carbs, as I dont like the look of the butterflys either. What a relief its not the head gasket! You can see the new original cap on the left is nothing like the one I had on my car!

[Lotusfab]

When the car is at operating temperature if I press on the leaking linkage the occaisonal spits stop. Tuned it by ear and rpm got it almost there using the colour and carbtune, then made the mixture slightly richer. Will get a krypton tune on it once I have rebuilt the carbs. ???

[Lotusfab]

Will be buying a copy of the Des Hamill Dellorto book. Only concern is removing the shaft bearings without causing damage. Anyone got an easyway of doing this?

[jonwat]

Only concern is removing the shaft bearings without causing damage. Anyone got an easyway of doing this?

Click

[Lotusfab]

Thanks John, thats what I needed to see.

[Lotusfab]

has anyone got pictures of the cooling pipes from the inlet manifold and water pump and where they join the rest of the cooling system. Just need to confirm my pipe arrangement is correct? Just have the pipe joined by a T piece which doesnt look right.

Edited September 26, 2015 by Lotusfab

[Lotusfab]

This is what it looks like. This was done when I got the car but it doesnt look right. Is there an aluminium piece missing?

Think also the pipe quality is suspect sonwill have to replace as they are degrading with heat. 

Like all things s1 the manual diagram bears no resemblance to the actual system!

[Lotusfab]

Or am I missing this bit? I have a late S1 but dontbhav either of these coolant pipes? Starting to think the set up is ll wrong, which would effect the efficiency of cooling?

[Lotusfab]

After having a detailed look I have the pipe in the top picture, assembled as in this diagram.

The only problem is I have two extra pipes not shown on the diagram, as shown in my car picture. The outlet from the inlet manifold and the cylinder head outlet that join via the T piece and head out forward through another pipe?

[jonroberts]

This is what it looks like. This was done when I got the car but it doesnt look right. Is there an aluminium piece missing?

Think also the pipe quality is suspect sonwill have to replace as they are degrading with heat. 

Like all things s1 the manual diagram bears no resemblance to the actual system!

The bent coolant pipe with the T outlet is correct.  The arrangement with the T piece on the hoses it not standard. I think you have a head with a heater outlet on it as well as an inlet manifold with a heater outlet. You only need one or the other so I suspect the previous owner joined them together. Possibly a replacement head ? 

I think Paul had a similar situation with his head ?

Edited September 27, 2015 by jonroberts

[marcbria]

The head you have with the outlet at the back is supposed to help deal with a hot spot at the back of the head. From my understanding and Jon seems to agree it replaced the intake manifold with an outlet at the back. That hose should run up to the inlet on the heater matrix through a dedicated pipe though the car. Seems to me like having both connected would reduce the amount of flow from the intake manifold into the head and also bypass the outlet port at the back. Its hard to predict which way coolant would flow, out the end of the intake manifold into the head/off to the heater or out of the head back into the intake manifold/off to the heater. Either way it doesn't seem ideal, in one situation you get cooler coolant flowing up to the heater matrix and in the other you get hotter coolant heading back into the head. Others may chime in but I would cap the end of the intake manifold, delete the T connection and keep the outlet on the head since it was introduced later to remedy something.

Brian

 

Heres and example with the hose coming off the intake manifold:

And one with it coming out of the head.

 

Edited September 28, 2015 by marcbria