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'73 vs '74  Rating:  Rating
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 Posted: 07-01-2011 01:46 pm
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Ramp
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There seem to be minor interior cosmetic differences between '73/'74.  I understand that there were some changes to the engine in '74.

I am looking and thought I would stick with a '74 but found a '73 I'm interested in.  Any reason I should not buy a '73 ?  Or, what engine modifications should I make to a '73 to bring it to '74 specs - other than improvements that apply to all engine years.

Also, does the wood kit fit a '73 - the center console is different than the '74


Thanks

Randy

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 Posted: 07-01-2011 02:40 pm
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Brett Gibson JH5 20497
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Randy, early engines use a rope seal for the crank shaft ends verses a true rubber / steal seal on later versions, not sure on the cut off piont but I believe it's in the range your looking at. As for interiors personnally I like the later versions center consul verses the tupper ware look of the early ones, but thats just my own opion.

Brett 

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 Posted: 07-01-2011 02:46 pm
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Ramp
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I also like the later interior and don't see why I couldn't convert the center console and wood kit later on as a project. 

As to the crank seal I assume then if/when I have a leak I can upgrade to the new seals - assuming the block and crank are the same.

Too bad your all the way north of me ! Would like to see yours.  I'm on Log Island but also spend weekends in the Catskills - around Monticello area - which is where I will store the JH for the winters and do some of the improvements.

The car I'm interested in is Skoska's - he had a few posts on the board about the car.  Looks like its in nice shape.

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 Posted: 07-01-2011 03:58 pm
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subwoofer
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The rope seal engines can not be upgraded to later spec, just so you are aware of that. The mk2 engines can be upgraded all the way to Excel SE spec - more or less anyway.

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Joachim

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 Posted: 07-01-2011 04:07 pm
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Brett Gibson JH5 20497
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Center consule's can be switched out easy enough, rope seals your stuck, that said a properly installed one along with the correct oil (ZDDP)?. will last a very long time.

 

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 Posted: 07-01-2011 04:17 pm
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Ramp
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Thanks for the advice all.  So, I would be stuck with the old seal type on a '73 if/when it was leaking - no big deal.

Still, haven't heard any reason's I should NOT consider a '73 ???

Although  - -  "The mk2 engines can be upgraded all the way to Excel SE spec - more or less anyway."  As I like to do mods/upgrades, should this be a concern ? What else can'r I do to a '73 that I can do to a '74 ? 

- I guess, when/if I get into it, I could always buy a '74, restore it/modify it and then swap it !! This could be a fun winter project !!

Thanks

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 Posted: 07-01-2011 04:59 pm
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Jensen Healey
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Hi Randy,

I have a '73 with the lip seal. If you see a breather box at the firewall with the oil filler cap on it it's an early engine. The filler cap was moved to the intake cam cover on the 2nd gen engines.

Kurt

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 Posted: 07-01-2011 06:58 pm
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Ramp
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Not sure if you can tel from this but here's a pic.  The oil fill is obviously on the cam cover  - but that could simply be a cam cover swap.

Attachment: Engine 907.jpg (Downloaded 104 times)

Last edited on 07-01-2011 07:17 pm by Ramp

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 Posted: 07-01-2011 07:00 pm
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James Sohl
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Ramp,  There are internal differences regarding oil control.  In early engines, the oil return passage from the exhaust-side cam box down to the sump tended to ‘air lock’, that is, windage and other sump conditions would slow oil draining back to the sump just enough to cause the cam boxes to slowly retain oil and fill up.  It made the inherently difficult to seal cam covers that much more likely to leak.  Also, oil flow to the camshafts themselves was a little excessive, making matters worse.  There is no fix for the oil return.  Later blocks are simply different in more ways than just to accommodate the lip seal.  There are threads on the board describing how to put an orifice in to the oil passage that feeds the head, improving oil pressure generally, and lessening the tendency for oil accumulation in the cam boxes.  The 907 engines are very much like any other Lotus product, continuous changes, poor documentation as to which change started with which (engine) serial number, and of course, LOTUS: Lots Of Trouble Usually Serious.  Your mileage will vary.  Actually, my ’73 ran quite reliably for almost three years, until I moved to AZ (and parked it.)  It did leak oil from many places including those described above.  I would not hesitate to buy the latest serial number I could find.

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 Posted: 07-01-2011 07:22 pm
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Ramp
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James - thanks, awesome info.  So the block is different earlier/late 907's -crank seal and oil flow design  - and neither can be retrofitted. 

Anything else different in 907 reiterations ?

Still haven't heard a reason I shouldn't buy a '73.

One of the reasons I'm actually interested in the JH - other than fun driving - is the ability to tinker - one goal is to do my first engine out -even if just to clean and detail the engine and bay plus some minor plug/play upgrades.  Should be a fun winter project - I'm not new to turning a wrench but never had the oppty to take an engine out and its on my list.

Maybe one of you guys can tell if this engine is early or later version.

Thanks

Edit:  James - I had read about tapping an oil feed on the head and plugging it to improve pressure.  Is this something done on all 907's or only the early versions ?

Attachment: Engine 907.jpg (Downloaded 106 times)

Last edited on 07-01-2011 07:26 pm by Ramp

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 Posted: 07-01-2011 07:54 pm
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Art DeKneef
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Just some rambling here on the information provided so far and my general opinion.

There isn't that much difference between the 73 and 74. Remember all cars go through changes and usually the later years are nicer because of the changes throughout the years. If you think the 73 would be a better car for you go for it. There are several examples of 73s that are still running.

There isn't much difference in the engine specs between the 73 and 74. There are improvements that were made to the car to improve  reliability and looks. Some you can do easily enough, others you can't. Changing the interior is usually just taking out the old and putting in the new. Again in general this applies to the early and later JHs and the GTs.

Engine modifications are pretty much the same between all the engines. It will depend on the car you get and the money you want to spend. There have been several discussions here about engine mods and the order in which to do them and the associated cost that goes with it. If you haven't already read through the different topics for the discussions.

Regarding the picture of the red car. Is that the 73 you are looking at? It appears to me to be really clean and looked after. Does it really need the engine bay detailed? If you look down from the washer bottle to the engine you should see the serial number. Post that and we can tell you more about the engine. Maybe at some time in the past a later engine was installed.

Is the oil pressure bad on the car that you are concerned about that you want to make changes? If not, why worry about that right now.

Art

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 Posted: 07-01-2011 08:08 pm
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Ramp
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That's the one I'm looking at - waiting for the owner to get back to me.  No worries, just curious about finding out all I can before buying.  From the cars I've seen this looks like one of the best conditions - although it does have 90k on it. 

Curiously, I made an offer for 1/2 the insane asking price on a car nearby at a collector car dealer - looks like its in fantastic shape, 50k, all original and they just accepted my offer.  Buuut, the car is green - basically the only color my wife does not want and not in my top 5 list - so I'll probably pass.






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