Elan S4 rebuild - my story chapter 2

[Certified Lotus]

I had such a rewarding experience rebuilding my '64 Elan S1 and then driving it all over the back country roads that I started looking for another "project". These are such great cars and now that I know them "intimately" I figured I should use my knowledge and experience on other cars. I certainly don't have a huge amount of spare time, but I found that if I stay focused and give myself blocks of time on weekends I can get these rebuilds done in a fair amount of time. Of course, help from my friend Drew is a very big plus as he is both a great inspiration and very knowledgable on the restoration of classic cars.

The search didn't take long and I recently acquired a nice '69 Elan S4 that had been under restoration and modification for more than 30 years but not put back on the road. The PO was very diligent about the work, with a full frame off rebuild and the standard of the work top notch. Along the way the previous owner had made some mods to the car that are tasteful but not quite original. The major one being a weber head and a flat bonnet. The plan for the PO was to build a "Sprint" car. The PO was very clear that this was not an original car regarding the engine, so I was well aware.

When I purchased the car, the title read "1969 Elan Sprint". I did some research and it looks like Sprint's were available in 1970, not 1969. Perhaps someone can clarify this for me. The serial number for this car is 45/7941Z. Any insights would be greatly appreciated.

Stay tuned, those of you who have followed my S1 rebuild thread know the details will be forthcoming regarding the work being done on my S4

S4 waiting for treatment

[trw99]

Glen, looking forward to following your next project!

The Sprint did not come onto the market until 1971. The Sprint concept and Big Valve engine were announced at the Oct 70 London Motor Show. Production did not start until very late 70/early 71 and the car was launched to the press in Feb 71. More info available on my web site, below.

Your 'genuine' S4 came off the production line on 18 Jun 68, well before the Sprint concept was dreamt up, with a LP prefixed engine.

Tim

[gjz30075]

Wow, right on my 18th birthday! Glen, do you think you'll have both cars at Princeton next year (LOG 36)?

[Certified Lotus]

Tim, thanks for your input and detail on this car. I was very surprised to see the word "Sprint" on the title for a 1969 car, but I thought maybe I don't know enough and decided to,ask this well informed community. Now I wonder how the title got to read this way........

Greg, no idea if I will have both cars at LOG36. But I know I'll be there with one of them

[Certified Lotus]

I had spent the last couple of weeks cleaning the S4 of all the mouse droppings, nests and shredded peanut shells that were all over the car. Sprayed the entire boot, engine bay and interior of the car with disinfectant and let it air out. Then put clothes dryer freshener sheets (bounce) in the interior parts to get rid of any hint of mouse odor.

With lots of evidence that mice had used this S4 as a "home" while stored in a garage for 30 years, I was concerned that parts of the wiring plastic shield would be eaten away. After a very thorough investigation I was surprised nothing was touched. Amazing.

Knowing the engine had been completely rebuilt, run and then in "storage" for 30 years, i took out all the spark plugs and used a fiber optic light to inspect each piston and cylinder wall. Everything looked brand new, but the rear two plugs were black which meant the webers weren't functioning properly when the enigine was run. I poured Marvel Mystery oil down each of the spark plug holes, enough to cover the Pistons and hand cranked the engine a few turns to get the oil spread around and hopefully seeping down the piston walls. Put the plugs back in and hand cranked the engine a couple for times over the next couple of weeks.

Drew came over to help on Sunday and we talked about what we wanted to accomplish during the day. Agreed to document what didn't work on the electrical system and try and get the engine running.

The generator and voltage regulator was out of the car and the fan belt was old, dry and cracked. I got a new fan belt and installed the alternator, original bracket and voltage regulator. Checked the wiring diagram from the factory manual for proper location of all connections.

Bought a new battery and trickle charger and installed it in the boot. Left the positive connection loose in case once the ignition was turn on electrical gremlins might fry any part of the wiring. A turn of the ignition switch produced no smell of burning wiring. A good start!

New Battery installed

Started checking all the switches, lights and any other electrically operated equipment for function and made notes of what didn't work. Small list that is very manageable.

We raised the car on the lift and removed the fuel from the tank via the drain plug. Put a cloth under the draining fuel to see what type of residue was in the tank. The fuel was clean and although it smelled old, wasn't brown in color which we expected. Another pleasant surprise.

Removed the fuel line from the tank to the webers and blew it out with compressed air. Once again, put a clean cloth on the end of the fuel line to see what came out. Clean again! Installed a glass fuel filter next the tank and put 5 gallons of 93 octane fuel in the tank.

We moved to the other side of the car and Drew disassembled the webers removing all the jets, floats, etc. and soaked them in lacquer thinner cleaning each part and insuring all the jets were clear. The carbs were completely dry when we took them apart. Reassembled and poured gasoline in the float bowls so the mechanical fuel pump wouldn't have to work too hard.

Weber carbs to be cleaned

The inside was dry as a bone

While Drew was in the midst of carb cleaning I went about cleaning all the chrome to see what what kind of condition it was in. Everything was very coated and tarnished. Just about everything polished up nicely so no major concerns here.

Confirmed that the points and spark plugs were gapped appropriately and that the plugs wires were in the right order. Confirmed we had spark to the plugs. Oil pan was full of nice clean oil. Looks like everything is a go. Time to try and start the engine.

Turned the ignition switch and the engine cranked over nicely. We confirmed that fuel was flowing through the glass fuel filter. Cranked the engine some more and all of a sudden got a very big backfire from cylinder number three out of the carb. That spooked us.

Brought out the manual and confirmed firing order, retraced the plug wires to the distributor cap and doubled checked all connections. Everything seems ok. Cranked the engine over again and after a few revolutions got another very large backfire from cylinder 3. Odd........

It was the end of the day for us and we decided to put everything away and come back to this another time. Perhaps timing issues? Not sure but I've got the week to think about it and hopefully get advice from those on this site who may be more knowlegable. Would appreciate any input!

[alan.barker]

i would suggest you remove camcover and turn engine by hand to see if all the valves are opening and closing.
Sorry but a little reminder firing order is 1 3 4 2.
good luck
Alan

[john.p.clegg]

i would suggest you remove camcover and turn engine by hand to see if all the valves are opening and closing.
Sorry but a little reminder firing order is 1 3 4 2.
good luck
Alan

and check both valves are closed ( TDC ) as the rotor arm passes the associated plug lead pickup

John

[carrierdave]

Hi, you need to check that he position of the rotor arm for firing on number one cylinder coincides with the correct HT lead on number one cylinder.
Rotate the engine until the mark on the crank lines up with TDC on the timing case. Then take the oil filler cap off and check that the lobe on the cam is pointing towards the intake cam, ie the valve is closed. To check and compare the position, if you rotate the crank through another 360 degrees, and look at the lobe again you will see that the valve is open and the lob is pointing down.
Rotate back through 360 degrees, then take the distributor cap off and compare the position of the rotor arm with the position of number one lead - do they line up? Then from that point, is the firing order correct, 1,3,4,2? Also are the points just about to open? rotate the engine 10 deg lso that the crank mark lines up with the mark on the timing caseup and then check to see if the points are just opening (use a circuit tester).
If not, then you will need to release the distributor clamp and rotate the distributor until the circuit is broken.
good luck

[Certified Lotus]

Alan, John and Dave, Thanks for your suggestions and insights. I will pull the valve cover next and hand crank the engine to see if the valves are in the right position. Drew and I had already done the Top Dead Center measurement in relationship to the distributor rotor and everything seemed in order. I was very careful about the firing order as the plug wires were numbered in sequence from front to back (1,2,3,4) but the actual firing order was correct (1,3,4,2).

Now that I am better informed will go thru everything again to insure that the engine is properly set up.

The interesting thing is the PO told me he got the rebuilt engine back from the shop and installed it and then ran it in the car for a while without issues. Then it sat for many years. I wonder what changed from sitting in storage?

[pharriso]

Alan, John and Dave, Thanks for your suggestions and insights. I will pull the valve cover next and hand crank the engine to see if the valves are in the right position. Drew and I had already done the Top Dead Center measurement in relationship to the distributor rotor and everything seemed in order.

I'm also thinking that the distributor could be 180 degrees out, so #1 could be sparking when the piston is near TDC but you're on the Suck cycle as opposed to the Bang cycle (using the Suck Sqeeze Bang Blow model...)

Was the distributor pulled out to set the points?

[Certified Lotus]

Phil, that thought crossed our minds too. We didn't pull the distributor out. Just the cap off and hand cranked the engine with the plugs out and a screw driver sitting on top of the Pistons watching for TDC and the rotor position. Everything matched as it should with proper firing order. But your right, we don't know the valve position at this point. Removal of the valve cover will tell all!

[carrierdave]

You can carry out a quick check by changing over the plug lead positions - assuming you are 180 degrees out,

Move lead 1 to plug 4
Move lead 3 to plug 2
Move lead 4 to plug 1
and finally lead 2 to plug 3

I'm pretty sure that's right.

[pharriso]

You can carry out a quick check by changing over the plug lead positions - assuming you are 180 degrees out,

Move lead 1 to plug 4
Move lead 3 to plug 2
Move lead 4 to plug 1
and finally lead 2 to plug 3

I'm pretty sure that's right.

They probably wouldn't reach... but I'm assuming you could move the leads at the distributor cap end instead?

[elancoupe]

Removal of the valve cover will tell all!

Assuming that you don't have an oil splash shield installed, you can always peek in the oil cap hole, and see the position of #4 exhaust. IIRC, at TDC, the two #4 lobes should be pointing towards each other.

[prezoom]

Pull the spark plugs, put the car in gear, then stick your finger in the number one plug hole, and roll the car forward. You will be able to feel the compression of the air on the compression stroke. When you start feeling the air, then use the screwdriver to roughly gauge TDC and double check with the mark on the pulley. Then see where the plug wires go.