GavinT

I’d be interested to know pricing - 88MY Stevens USA Spec (same chassis as 87 HCI)

There is a theory that keeping the heater on all the time aids coolant circulation around #4 cylinder. Helping to reduce the hot spot around that cylinder and reducing the possibility of gasket failure. True or not, I don’t know. But since the rebuild of my Stevens turbo I’ve been following that practice.

I’m in on the engine snubber / stabilizer

Do you have a work shop manual?

You beat me to it Steve. Was looking around the web for an S1 wiring diagram to post. I made a mistake….I referred to a black yellow wire but is actually black orange.

That third spade connector has been modified to fit over the left prong/pin on the otter switch. If the spade being disconnected from the prong is how you found it, then your cooling fans have not been working. Turning the ignition on, not starting the engine, will send power to the fans. Connecting the black/yellow and black wires together will complete the ground/earth circuit for the fans and energize them. Connect them together before turning on the ignition. If you have established the fans are working the next step is to test the otter switch. Re connect the third spade to the left prong of the otter switch. Then start the engine and allow things to warm up. Keep an eye on the temp gauge. The fans should come on as the temperature gets up between 1/2 and 3/4 on the gauge. Hopefully everything works and you are good to go. At this point I would replace the black/yellow connectors for one that fits the prong nice and tight. If the fans don’t work then the otter switch is faulty. It’s a cheap part. Call JAE and have them send you a new one.

Hi Tristan, yes - that’s your thermo / otter switch. And the black/yellow is disconnected from its pin. Your fans have probably not been running. Connect the black and the black/yellow together and the fans should run. Being black wires, I think the otter switch completes the ground circuit and the fans are wired constantly hot. I’m away from my car and circuit diagrams so I’m doing this from memory and I can’t believe I did the wiring mod in 2010. Time flies! at-least they have a good clamp holding the otter switch in the pipe but those connectors are messy. Test the otter switch when the car is hot and see if you get continuity across the pins. I’ve never had my temp gauge go over 1/2 in traffic. As soon as I hit traffic I switch on the fans. I don’t wait for the temperature to climb. Going done the highway the temp will be at a 1/5 above cold. Not sure of the code but Lotus called the paint color Lemon Yellow. My car was repainted in the 90’s. My vin is 165H.

Yes, those are the original fans. The fans on an S1 are triggered by a thermo switch located in the aluminum coolant pipe by the alternator. It’s a two wire switch. Bridge these two wires with a small length of wire and the fans should run. If they do not then check the fuse. The wiring connector that pushes onto the thermo switch has been known to become unseated during driving resulting in a bad contact. Get some wire and wrap it around the connector and the aluminum coolant pipe. Effectively clamping the connector onto the thermo switch. The wiring for the coolant fans is not not very good on an S1. All the current for the three fans is drawn through one wire and a single fuse with no relays. An upgrade to consider is a three relay re-wire that uses the original Lotus wiring to trigger the relays. You basically separator the fans into three separate circuits. I did this on my S1. I think I have a post somewhere from years ago giving details. You can also add a manual override switch. I have this too. Pretty much every time I sit at a light for any extended period I just throw the switch and run the fans. Upgrading the fans will improve things. I just got some modern fans off eBay and made some brackets to mount them to the radiator. I also have an aluminum radiator. In my experience, the aluminum radiator is way more efficient than the original.

I’ve used the Mann W920/21 for years. Quality product made in Germany. if you pre-fill the filter with oil and then hold it horizontal you can gauge how much oil is retained in the filter after shutdown. The Mann filter retains a considerable amount. I’ve always got good pressure within seconds of engine start.

I don’t have the stabilizer on 165H. Perhaps if there is enough interest we could get a run made up. Really enjoying this thread Dave. Engine looks terrific!

I would remove the oil feed to the turbo and hand pump oil into the block. Pump a good amount in, like a a 1/4 of gallon. With the cam covers removed fill the sump by pouring oil over the cams. With the plugs removed, mist the cylinders with an oil spray - WD40 maybe. With the ignition disabled, spin the engine on the starter. You should get oil pressure fairly quickly. Once you establish you have pressure, keep spinning the engine. Don’t over do it but enough rotations to get the oil well and truly circulated. Then check for leaks. If your real lucky the front and rear crank seals will hold. Best of luck!

I read many posts warning about the new replacement racks not being as good but out of convenience and time I just went with the a new one. It may turn out to be a $695 mistake.

I just installed a rack from JAE which I believe is from SJs. First thing I noticed was the ratio is totally different. I plan on rebuilding the original with the kit from Lotus Marques as I think it’s just the inner tie-rod bushings that are worn.