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Heater Plenum Grille Body Detail

PostPosted: Wed May 30, 2018 9:49 pm
by Elanman39
Hi, I'm currently trying to detrmine how much of a 26R S2 I am restoring is original... So far and unsuprisingly I can rule out the engine and the chassis, but the body looks hopeful as it has several less obvious 26R S2 features such as the high floor over the diff area and the swollen inner rear arches plus of course the external arch flares, Chinese eye lamps etc. One thing that is worrying me was that the car has a heater plenum entry grille fitted, which shouldn't be there in my opinion as I don't think they weren't fitted on the 26R S2. Looking more closely however the grille sits on the top surface of the scuttle, not in an indent in the fibreglass like that on my roadgoing S4. Did all roadgoing Elans have the grille indented? If so then it seems the 26R has had a hole cut post factory to allow a heater to be fitted and I can relax a little. The car has been in Sweden all it's life up to recently so a heater would make sense....
Many thanks for your thoughts.

Re: Heater Plenum Grille Body Detail

PostPosted: Fri Jun 01, 2018 1:00 pm
by nmauduit
sounds like an interesting project... would you post some photos, esp. of the diff area ? thank you

Re: Heater Plenum Grille Body Detail

PostPosted: Sat Jun 02, 2018 3:51 am
by Elan45
I don't seem to be able to reply to this topic this evening as a PM, so here is may reply.
I have 3 S3 Elans, an early FHC and 2 DHC. All have the recessed opening for the vent grill. I also have a piece of S2 bodywork which includes the vent and it too is recessed.

You sound like you know 26R's pretty well.

My earliest DHC was converted to a street driven 26R about 1970 by the original owner.He was a medical doctor and supposedly was known to the people at Cheshunt where he bought all the parts available. Dr Counts died about 1973 and I bought the remains of the wreck (attributed to his son) from his widow in 1984, so I am the 2nd owner. The car started life as an SE and now needs a replacement nose. I intend to install 26R flairs to the front, where it was crashed. The frame is straight; looks like the damage is all up high. The timing chest was broken off the head and I have a replacement engine which came from the Jackie Oliver 26R which used to be here in Columbus.

So, I have a project Elan that has adjustable length wishbones, 3 master cylinder brake/ clutch, 26R ser 2 hubs w/ Ser 1 wheel set w/ radials mounted, ser 2 wheel set w/ race tires mounted. The rear are flaired and the inners are modified for clearance. Small diam rear springs and very heavy springs and F& R sway bars. 26R Hooke joint crossed roller half shafts and a Salisbury LSD diff, But I don't see a raised floor above the diff. I've heard about higher positioned rear cross-member and strut towers. Is this the reason for the higher floor? How much is the cross member raised and how does it affect handling? Since it is getting more difficult to get in and out of my Eleven and 20/22, this project is becoming more important to me


Re: Heater Plenum Grille Body Detail

PostPosted: Sun Jun 03, 2018 11:44 am
by Elanman39
Hi Roger, thanks for your reply and your information which backs up my theories.

I have also struggled with the personal mails, in fact I replied to one from Dave Hughes (Big Valve Head) but have heard no more from him and don't know if he received it or not. Dave, are you out there?

SInce my original post I have done some more internet and book based research and it does look as though all normal road Elans from the first S1's through to the last Sprints had the heater intake grille recessed into the scuttle top. The Series 2 26R's had no heater intake on the scuttle and there was no recess there either. I don't know about the series 1 26R's as I have struggled to find pictures of known original cars where that area can be clearly seen. Modern 26R replacement bodies mostly seem to have a recess, but usually the hole is not cut and the grille not installed. Maybe this is a handy trick for spotting replacement bodies on "completely original" 26R's? The car I am restoring has no recess but it does have a hole cut and a grille fitted. There is no evidence on the underside of the scuttle of any grp work to remove a recess and so I am drawn to conclude that the body is an original S2 26R which at some stage in it's life had a heater fitted. The car was based in Sweden all it's life and was used on the road latterly so this does make sense.

Before I try to answer to your questions I am by no means an authority on the 26R (23B's are my primary interest), this is the first one I have restored and as with so many things it's a case of learn as you play. The one thing I am certain of is there is a lot of bad information and non-genuine cars that claim to be otherwise out there so a degree of caution must be applied to everything you are told. If you know something that differs with anything I say please tell me, with luck and common sense we can then work towards understanding what is correct (in our minds, at least!)

The so-called high back chassis was I believe introduced on the series 2 26R. Although several people have told me that it was done purely to make installing/changing the diff easier I think this is wrong. The diff height on the standard Elan is such that the centreline of the output shafts is around 5.5" above the bottom flange of the chassis. If the car is fitted a tyre with a rolling radius of 11.5" such as a 5.50x 13 as fitted to the s2 26R then the driveshaft will only be horizontal when the rear ride height is 6". If the car is run at a lower ride height such as 5" as specified for the 26R then the driveshaft will be angled upwards as it moves outboard and this will give a small but significant power loss. Lifting the diff will reduce this loss and I think this is why the high back chassis was introduced. Certainly in my experience Lotus rarely did anything purely to make the mechanics life easier.... :roll:

As I said my car doesn't have the high back chassis but I will be fitting one in the restoration. The body suggests the lift in diff height is about 1" but I will confirm this when the new chassis arrives. The lift is achieved simply by mounting the diff upper crossmember higher than standard so there is a step between the upper flange of the two diverging panels either side of the diff and the top of the upper crossmember. I assume that the strut turrets must be commensurately shorter to keep the strut tops in the same place as mycar is fitted with a standard chassis and the upper body to tower mounts look to be in the normal place.

I attach a picture of the underside of the body that clearly shows the raised section to allow the higher crossmember to fit.

Congratulations on your list of cars, I assume the ex-Yamura 20/22 is one of the ex-Jim Russell "Grand Prix" cars? Lovely.....

Best wishes, Nick

Re: Heater Plenum Grille Body Detail

PostPosted: Sun Jun 03, 2018 11:59 am
by Elanman39
Hopefully here's the picture.... Also a couple of pics of the grille and the car just for the hell of it.