1964 Lotus Super Seven Engine Questions

[TEM]

My new (to me) Lotus arrived last weekend and I'm starting the long process of getting it back on the road.  So, this may be the first of many questions.  Car has been off the road since the early 70's.  Car only has 2200 miles and still has its original top and tonneau cover and, gasp, tires.

1) The engine block shows "109E" in the cast numbers but the head has "116E". Is this the definition of the 116 engine?

 2) I located the timing mark on the front pulley but what do you line it up to?  Is it the left side of the casting rib (red line of the attached photo)? rad0fmt4.bmp 

3) What is the correct cylinder compression.  I am reading 150, 190, 165, 125 psi on cylinders 1-5 respectively.  Spark plug were all on the black side with the exception of cylinder #1 which is brown, almost orange.

 

[MV8]

It appears that no oil was added to the bores before the testing (not run since the '70s?) and the rings scrapped the rust off #1 and on to the plug. I would add a 1/4 cup of marvel mystery oil to each cylinder and slowly rotate the assembly through twice, then let it sit a day before motoring with the starter with rags over the plug holes to help catch the residual if any, then put the plugs in and get it running and hot, then change the oil or you can do another comp test. I would toss out the results of the first test.

 

Is the picture of the crank pulley shown with the crank at tdc?

 

Car looks great!

Edited November 18, 2023 by MV8

[TEM]

The plugs were pulled to add oil before any engine cranking.  This is what the plugs looked like before any cranking.  The Compression numbers are after adding oil to each cylinder.  I will add a cup of MMO to each cylinder and let it sit, maybe the rings are stuck in the pistons.  The engine is a little ways away from running.  I have to rebuild the Weber's first.  But you are right, I need to get it running first before the compression numbers have any meaning.  I did this test just to check for any major damage like a hole in a piston.

 

I'm not sure where TDC is thus my question.  I know where it is approximately by observing the rocker arms while rotating the engine by hand.  But I would like to know where the Zero deg mark is on the block so I can set initial ignition timing.  I'm questioning this casting rib because when the timing mark on the pulley is aligned with this rib the rotor is pointing toward the #3 cylinder (as originally wired).  Either the HT leads were in the wrong location or the engine was set to some crazy high spark advance.

 

 

[7Westfield]

I guess that rib is the timing mark---doesn't look the same as a xflow, but it's in the right place

distributor rotates CCW

firing order  1 2 4 3

[TEM]

My very rough estimate of TDC is somewhere around that red line.  I cranked the engine by hand and noted where the intake valve closed and where the exhaust value opened on the #1 cylinder.  The half way point gives me about where the red line is on the photo.  Tomorrow I will pull out the timing light and set initial timing to this mark.  Hopefully its close enough to get it started.

[MV8]

I think the engine tdc mark is just clockwise of the red line and 8-10btdc is probably the other line ccw from the red line. I'll assume you want 10btdc. If not, substitute below:

 

I would verify tdc and mark the pulley to align with the engine tdc mark, then use a dial back timing light to set 10 btdc to adjust the distributor so the light shows tdc.

Instead of having only the tdc mark, if you want to verify or make a 10btdc mark on the engine, while it is still running and the timing set to 10btdc, zero the timing light knob so it will act like older, non-adjustable timing lights to show the actual timing. The light should show 10btdc with the pulley. Then mark the engine for 10btdc for when you don't have a dial back timing light.

 

You can determine actual tdc with a foot of 1/8 inch steel rod for $2 (or any thin, rigid rod that isn't fragile), a wrench, some tape, and any reference point on the engine behind the crank pulley.

 

https://www.homedepot.com/p/Everbilt-1-8-in-x-12-in-Cold-Rolled-Plain-Round-Rod-800397/204331423

 

Pick your reference point and with the engine near tdc, wrap two inches of masking tape over the belt groove in that area. Insert the rod through the #1 plug hole to touch the piston. It won't go far and is too long to drop in fully at any crank position. With the rod between your fingers and hand over the plug hole, rotate the crank slowly with a wrench in either direction. You will be able to feel which way the rod is going. Rotate in the direction pushing the rod out until you feel it starting to go back in, then mark the tape at the reference point on the engine. Rotate the opposite direction, pushing the rod out until you feel it starting to go back in, then mark the tape again. If you are consistent, TDC will be halfway between the two marks.

 

An alternative to the dial back timing light in finding 10btdc is to use a protractor directly off the crank bolt or make a degree wheel out of cereal box or poster board using a protractor.  

 

116E has a timing tab on the  timing cover. 109E has no cover in the timing tab area (about 35 deg from vertical). I assume a cross flow head was fitted to the non-crossflow block? Hard to see from the pics .

Edited November 19, 2023 by MV8

[TEM]

Thanks MV8,

 

This is a very similar procedure to what I use on my Europa to find TDC but in that case I have to use a straw because the pistons are wedge shaped and the spark plug comes in from the side so whatever you stick into the plug hole gets crushed on the up stroke.  Given my experience, I didn't want to stick anything into the plug hole until I knew what I was dealing with.  It seems the Seven Kent is more similar to a Lotus twin came in that you can stick just about anything in the hole without fear of it getting crushed.  I'll give it a go today.

 

I plan to use the timing light as you mention but it is useless without first knowing TDC.

 

Now you have me even more interested in knowing what engine I have.  I have no timing cover, the block is "109E" and the head is "116E" and it is definitely not a X-flow.

[Joe Petty]

109E is the 1340 cc 3 main bearing (the 20 minute engine) and 116E is 1500cc 5 main bearing engine.  Yes, both are pre-crossflow.

Be gentle and Good Luck!

[MV8]

I tweaked my previous reply. May be difficult to keep the rod from falling out since it is a foot long and won't be going in more than a couple inches at any point. May need to wrap your hand around the rod (four fingers) loosely with the base of your hand against the head just to hold the rod at the plug angle. The goal being not to bind the rod at any point when raising the piston. Any resistance turning, stop, feel if the rod is still free. Any confusion or questions, stop and post or pm.

[7Westfield]

I haven't needed a piston stop for quite a while, but next time, I'm just going to gut an old spark plug

Then either tap the inside for a bolt, or weld a slug into it

[TEM]

MV8,  I think that is all common sense.  I will raise the piston to near TDC before inserting the straw (might as well use my very expensive Boba tea special tool ).

[Christopher smith]

good advice you are getting. Not sure why the 1500cc type 116E head is on a 1340cc block but assume it fits. And yes- be gentle with that 3 main bearing engine. The mark on a normal 116E timing cover is for 10 degrees BTDC according to my Cortina shop manual.

[SENC]

I'll have tonight back through my notes and files, but my memory is that the two "pointers" on the cover are 8 and 10 degrees.  In the downloads "Lotus 7" section are copies of the Lotus 7 manual, a Ford 105E manual, and an article on the Cosworth evolutions.  The Ford manual shows the markings, but it may have been somewhere else I saw the description.  The Lotus manual and article describes various initial intended timings.

 

It looks like you have a Cosworth cover, so perhaps you also have a Cosworth head.  They did make them for both 105E and 116E engines.  How are you identifying this as a 116E head?

 

116E blocks, in my experience with Lotus, are most frequently marked 120E.  Think of 105E and 116E as "classes" that can include several subgroups.

 

It could be that yours was a Cosworth 116E engine where the block was replaced - or a 105E where the head was replaced - or maybe someone just added the Cosworth cover and new manifolds to allow the dual Webers.  I can't see the manifolds well enough to tell if they look like the Cosworth manifolds.

 

The unique engine number should be engraved on the top of the motor mount on the distributor side.  With that and your vehicle ID number (SBxxxx or LSBxxxx) John Watson (Lotus Seven Registry) could tell you if the block is original and maybe more about original configuration.

[SENC]

This from the Seven manual suggests that the gap between the 2 ridges is 10 degrees btdc.

 

 

I also found the following in my files.  Assuming this marking us how you identified your head, it may explain things as it appears the same 116e casting for the head was used on 1300cc blocks.  I think this was related to Cortinas, but would support such a head on a 1300 lotus engine.

 

[TEM]

Some pictures.  The only thing stamped on the head near the water intake is "185" stamped not cast.  Its very small and faint and does not show on pictures.  The number in the casting ("116E 6050 AB") is attached and is located towards the middle of the cylinder head.  The block is definitely a 109E as can be seen in both the cast numbers and the stamped numbers above the engine mount.

[SENC]

Interesting, I have not seen one with the markings on top (not that I've seen a lot, so could be common).  Attaching a picture of mine on rebuild, which also shows the intake manifolds - which I believe to be original/Cosworth manifolds.  Yours look quite similar.

 

On this one, like the diagram above, the 116e casting is on the bottom of the water inlet.

Edited November 20, 2023 by SENC

[Christopher smith]

Looks a lot like my 1500 5 main bearing type. Mine is early Cortina GT based ( rope seal type). 120E6015 now with a 2x40DCOE that looks similar except the intake is a welded fabrication instead of a casting.Looks like we all have similar fun with the correct special bolts and install sequence with those clamping the intake and header flanges.

[SENC]

1 hour ago, Christopher smith said:

Looks a lot like my 1500 5 main bearing type. Mine is early Cortina GT based ( rope seal type). 120E6015 now with a 2x40DCOE that looks similar except the intake is a welded fabrication instead of a casting.Looks like we all have similar fun with the correct special bolts and install sequence with those clamping the intake and header flanges.

Indeed, they are a real bugger!

[TEM]

I haven't had the pleasure yet

[Christopher smith]

For sure It is very easy to get it wrong, so you will want to be sure you note the location of the correct bolt types. The assembly sequence is also tricky since you may not be able to start the top bolt threads unless the manifold and header flange are a few mm away from the cylinder head. Or at least that was my experience. I found that cutting an allen wrench to shorten it a bit was the only way I could get at a couple of the bolts ( some by reaching from below). The Cosworth guys were geniuses for sure, but it was still tricky.