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Thread: HPC Questions

  1. #1
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    Default HPC Questions

    First, let me say that I understand there is debate as to whether a car is an HPC if it doesn't have H in the VIN. Not really interested in whether a particular car is or isn't something based on a letter in the VIN. I do have a couple of HPC questions though that are tangentially related to the VIN. And to be clear, I don't really care if I have a "true" HPC or not. If I have a Clubman with some of the HPC components that's perfectly fine with me. Just trying to learn a bit about all the nuances.

    @croc is kind enough to decode the VIN of Caterhams listed on BaT. Here's the decoding of the last one:


    SDKLDKCVXP0265300
    SDK = Caterham as the manufacturer
    L = Left hand drive
    D = De Dion chassis
    K = Kit built
    C = Chassis Type = Clubman
    VX = Vauxhall on carbs
    P = 1993
    Chassis number = 0265300


    I bought the one before that and the VIN is identical but the last three numbers are 500 rather than 300. Both cars have a Vauxhall engine under the bonnet with a red spark plug cover and a pair of Weber 45 DCOE carbs. Both are claimed to be HPCs with an uprated 218hp Vauxhall engine. The one above has the HPC badges and mine has Lotus badges.

    Every article I have read about HPCs indicate they have the Vauxhall engine which distinguishes them from a non-HPC of that era. Is a car originally equipped with a Vauxhall necessarily an HPC? Are there cars other than HPCs that were supplied with the Vauxhall engine?

    The Chassis Type in the VIN decode above is C for Clubman rather than H for HPC. Is there some difference in the chassis of a Clubman versus an HPC? If so, what are the differences?

    Finally, it sounds like an originally supplied Vauxhall with Webers can be stock and produce 175hp or be upgraded to 218, 235 or 250. I've seen some people write that the level of tune is indicated by the color of the L-shaped spark plug cover but that seems very unreliable as those are cheap, easily swapped out and seem to be changed with impunity. And most seem to be red or obviously not original. So, ignoring the spark plug cover which doesn't seem very reliable, how does one determine the original state of tune of a Vauxhall engine? I think the first clue is the size of the carbs as I've heard it said that the 175hp stock engines have 40 Webers and the upgraded engines having 45s. However, one can change the carbs after the fact also. I'm guessing that to really know what the engine is it's necessary to either find original documentation, ask Caterham or take the valve cover off and see what's marked on the cams.

    Thanks for any input. I'd apologize for delving into such minutiae but that's what these forums are for aren't they?

  2. #2
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    Hi Sander


    Congratulations on your new acquisition. I think you will have a fun time with your new Caterham.

    I went and looked at what I have in my notes plus referred to the L7C archives and the Chris Rees book.

    There are 4 separate Caterham HPC releases to be aware of:


    • HPC 1700 = 1986 HPC 1700 which was a 1.7L Ford BDR with twin Weber 45DCOE for 170hp (claimed - it actually was 160hp when tested independently). 62 produced in total. The BDR was an official option until 1995 in the UK
    • HPC VX = Launched 1990 but first delivered in 1991 HPC with a 2L VX on twin Weber 45DCOE carbs with 175hp. Red spark plug cover. Available as an option in the UK up to 1995. Chassis numbers within sequence 5253-30521 (not all of these were HPC its just they were interspersed within the sequence) and a VX code within VIN. Model had 16 inch KN ('Wagon Wheel') alloys, LSD, 7 logo on grill from 1993, leather seats, Motolita wheel, heater, spare tire/tire cover. Engine has VX and 4 digit suffix. Dry sump was an option.
    • HPC VXI = 1991 HPC with a 2L fuel injected VX (Bosch Motronic) with 165hp. Red spark plug cover. Available as an option in the UK up to 1995. Chassis numbers within sequence 5416-21149 and a VX code in VIN. Model had 16 inch KN ('Wagon Wheel') alloys, LSD, 7 logo on grill from 1993, leather seats, Motolita wheel, heater, spare tire/tire cover. Engine has VX and 4 digit suffix. 337 of the VX and VXI produced in total. Dry sump was an option
    • HPC Evolution = I think this was 1992. It was a 2L VX with Swindon Racing having upgraded them based on 3 levels (stages) of performance. Stage 1 was 218hp - identified with a blue spark plug cover. Stage 2 was 225hp and identified by a green spark plug cover. Stage 3 was 235hp and black spark plug cover. Available as an option up to 1998 in the UK. Supposedly only 20 of these engines were sold, mostly as aftermarket upgrades. Engines have VX and 4 digit suffix. Dry sump was an option.


    The really valuable HPCs are the BDR and the Evolution. Yours is neither.

    The next thing I would observe is not all VX-powered cars were HPC specification. They also got VX label in their VIN. So a Vauxhall HPC package was more an option pack for performance than a specific engine package. You could have a VX engined car which was not an HPC but had identical engine/gearbox and hp performance.

    The chassis type options post 1990 for Caterham were:
    S = Factory Built
    A = Alternative
    C = Clubman
    H = HPC
    L = Superlight
    O = Other
    R = Race chassis (or sometimes Road chassis)

    My observations:

    • Both your car and the car auction close after yours have chassis numbers that fit within the VX HPC sequence.
    • If you tick the boxes on your car you purchased you do have 45DCOE WEbers, heater, correct leather seats, red spark plug cover, spare tire mount, LSD.
    • But you do not have a Motolita wheel (its a more recent Racetech quick release - steering column was likely replaced for a quick release as the Motolita's were not quick release?), the KN alloys (no great loss to be honest - smaller wheels are better), or 7 in the grill (but that could be explained by you not having the original nose cone too - its a later shape plus later grill insert). Dry sump (Titan brand - not the original but installed in 2008). None of this is conclusive by the way.


    I would also add that my experience with Caterham VIN numbers has shown them to be arbitrary at times. The chassis type field is always a weird one with a lack of logic. A lot of US market Caterhams are designated A for Alternative and look how R can be both Road and Race! My suspicion which I cannot prove is that the HPC chassis type was reserved for the 1700BDR which was still available as an unmarketed option up to 1995.

    Where I come out from all of this is you have a VX HPC spec car. The fact that it does not have HPC in its VIN is likely explained by non-UK market export cars not being subject to the HPC sales option package at the UK Caterham dealerships although you could buy the pieces and create an HPC anyway. I'd call it an HPC.

    Don't get hung up on models. Just get out there and bounce off the rev limiter while going sideways and destroying another set of tires.

    Cheers
    mike
    Mike
    2010 Caterham CSR with Cosworth 2.3 Duratec
    2018 Caterham 420R with 2L Duratec 210hp at Donington UK
    1975 BMW CSL Group 4 (restoration finished - track set up time)
    1977 Holden Torana "A9X" (awaiting restoration)
    1985 Holden Commodore SS Group A (suspension restoration)
    1985 Holden Commodore Group A (suspension set up)
    1982 Ferrari 400i (radiator replacement)
    1965 Ford Mustang Fastback "Holman Moody"
    1992 Ford Escort RS Cosworth WRC (dyno time)
    1990 Range Rover 2 door Classic
    and another project car coming....

  3. #3
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    Thank you very much Mike. Like any 30 year old car that has been equipped for use on the track it doesn't perfectly match the description of any of the OEM models. In particular, the interior of mine doesn't seem to match the upgraded interiors I see in the original HPC photos.

    I had the original wheels reinstalled and I believe those are the 16" HPC KN Wagon Wheels you refer to. There's a photo below.

    Name:  B0CF49D1-8924-488B-8DCC-FCCA0FBBDE2B_1_201_a.jpg
Views: 83
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    So basically, it seems to have all the HPC specs except the steering wheel and perhaps the interior specs as you pointed out.

    The engine is the more interesting question. The seller says it's a 218 hp engine from Swindon. I haven't seen all the paperwork but there is correspondence from years ago when they were trying to get the carbs set up for life at 5,000 feet and that refers to the Swindon modifications. That causes me to think the engine has some sort of Swindon modifications. But there's the red spark plug cover which indicates it's a 175hp Vauxhall engine. Interestingly, Rees's book describes the EVO engines as having a blue (218), green (225) or black (235) spark plug cover but the photo of the engine in that chapter has a red spark plug cover. Even more interesting is the fact that of 20 Evo engines produced 25+ years ago, not one but two have purportedly been sold on BaT in the last month and both have the same red spark plug covers rather than the correct blue ones. So I'm not yet convinced one way or the other on that question. I'm guessing that when I see all the paperwork it will be clear. It seems that claiming a Vauxhall is a Swindon engine might be an easy deception but I don't think that applies in my case for other reasons I won't go into here.

    Regardless, I know I have a Caterham with a dry sump Vauxhall with Bilstein shocks. Beyond that it's just a question of what flavor of wonderful I actually have. We shall see.

    Thanks again for your input.

    Sander
    Last edited by SanderGA; 07-18-2020 at 05:15 PM.

  4. #4
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    Yes those spoked wheels are what I call 'wagon wheels'. They weigh a ton. Personally, I think you would be better off on the smaller wheels with thicker sidewalls. Less rotational mass, forgiving ride plus better communication through the seat of your pants when you are on the limit. Try them back to back and you will feel what I mean - its quite noticeable.

    Interior is correct for an HPC. Seats are the correct one. The headlight switches have been upgraded from plastic toggle to a better quality metal toggle but thats a good thing. The wheel has been upgraded to quick release Racetech probably when Rocky Mountain/Caterham USA did the Titan dry sump as the owner moved into track usage around that time. It looks fairly recent vintage Racetech. Gear knob was also upgraded from the black plastic Ford Capri knob.

    The engine was imported to the US from the UK. It would have been easy for Swindon to add the upgrade package and then ship it to the USA. Most of the stage 1 upgrade was just a more aggressive cam and a better tune. The base VX engine out of the Vauxhall Astra was done at a basic tune - it was not hard to get bulk hp out these engines, 320hp+ in BTCC racing. Paperwork will give a guide. Hopefully that paperwork will show a recent dyno plot which will confirm it is higher than a standard VX and that you have a Stage 1 Evo. George Alderman of MidAtlantic Caterham is still around and I could call him on this but he's in his 90s now and while he is as sharp and still a damn good driver, I doubt he would remember one car all that time ago.

    You have a great package in this car - will be good for backroads, track and autocross as you choose.

    Where is its new home going to be?
    Mike
    2010 Caterham CSR with Cosworth 2.3 Duratec
    2018 Caterham 420R with 2L Duratec 210hp at Donington UK
    1975 BMW CSL Group 4 (restoration finished - track set up time)
    1977 Holden Torana "A9X" (awaiting restoration)
    1985 Holden Commodore SS Group A (suspension restoration)
    1985 Holden Commodore Group A (suspension set up)
    1982 Ferrari 400i (radiator replacement)
    1965 Ford Mustang Fastback "Holman Moody"
    1992 Ford Escort RS Cosworth WRC (dyno time)
    1990 Range Rover 2 door Classic
    and another project car coming....

  5. #5
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    Thanks Mike.

    I tend to agree with you on the disadvantages of the larger wheels and Iíll likely go to the smaller wheels long-term. I put the large wheels on for transportation and breaking in purposes more than anything. I gotta get the thing from Salt Lake City to Atlanta and Iím considering driving it and shipping all the spares. The 14Ē wheels have track tires so Iím shipping those and will ship or drive the car with 16Ē wheels as they provide a bit more clearance. Sounds crazy but until Covid I had planned a round the country motorcycle trip so this is in that range of crazy.

    The big thing missing from the interior compared to every HPC photo is headrests on the seats. And until our exchange I thought the seats were vinyl based on the sellers description but I believe you are correct that they are leather.

    The funny thing about the HPC question is that there is only a question because thereís a Lotus badge on the nose. We know the Lotus badge isnít original and we know the nose isnít original. Ultimately Iím more concerned with the specs than the model designation. The biggest unknown is the engine. Iím going out to see the car next week and Iíll probably get that nailed down. Iím surprised Caterham or Swindon didnít put a permanent mark on the upgraded heads or blocks.

    is there going to be a NJMP gathering this year?

  6. #6
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    Swindon is still around. A bit of a longshot, but they might have some information on the various tunes they can share. Another option is to see if anyone on the c20xe Facebook page you mentioned on BaT know carb settings for stock cams and the various Swindon stages. I bet the chokes go up in size with each HP increase and that's an easy thing to check. e.g. if a stock vx engine uses 34mm chokes and yours are 38mm, then you know your engine is flowing a lot more air....or someone really screwed up the carbs

    -John
    '95 Westfield SEiW w/2.0L Duratec
    '68 Lotus Elan FHC
    '91 Miata w/Flyin Miata suspension & brakes
    '95 Porsche 993 C2
    '86 Porsche 944 turbo (neglected project car)
    Throttle Steer

  7. #7
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    Thanks JohnCh. The carbs are perfect...for 5,000 ft. of elevation so I probably can't determine much from those settings. Regardless of the settings, it's not producing 218hp at a mile high. My next step is collect all the documentation that comes with the car and see what that says. I'll be surprised if that doesn't convince me that it's a 218hp engine. Options after that in order are, get the carbs reset for local conditions by someone with a dyno because I have to do it anyway and get a dyno readout, call Caterham, call Swindon, or pull the valve cover and see what cam is in the engine.

    Honestly, I trust the seller and have no reason to think it's anything other than a 218hp SRE engine. Just fell down a rabbit hole of trying to prove it.

  8. #8
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    Usually it's jets and air correctors that change for altitude, not the chokes. But the chokes are frequently changed when going to more aggressive cams.

    -John
    '95 Westfield SEiW w/2.0L Duratec
    '68 Lotus Elan FHC
    '91 Miata w/Flyin Miata suspension & brakes
    '95 Porsche 993 C2
    '86 Porsche 944 turbo (neglected project car)
    Throttle Steer

  9. #9
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    Quote Originally Posted by SanderGA View Post
    My next step is collect all the documentation that comes with the car and see what that says.
    Yes - there was a photo of documentation during the auction but the details never were readable and it was vague.


    Quote Originally Posted by SanderGA View Post
    ... get the carbs reset for local conditions by someone with a dyno because I have to do it anyway and get a dyno readout....
    Even if it is not a stage 1 Swindon then its relatively cheap to add the camshaft yourself and re-tune. I think the car will be happier at sea level.


    Quote Originally Posted by SanderGA View Post
    I’m surprised Caterham or Swindon didn’t put a permanent mark on the upgraded heads or blocks.
    Swindon should have. BTCC cars got Swindon engines and they had an identifying mark so they would know it was theirs when it came back in for rebuild.


    Quote Originally Posted by SanderGA View Post
    Just fell down a rabbit hole of trying to prove it.
    Yep - done that many times myself.


    Quote Originally Posted by SanderGA View Post
    The big thing missing from the interior compared to every HPC photo is headrests on the seats.
    Headrests and seats still come up for sale on the Lotus 7 Club UK from time to time. Those older style seats were better quality than the current Caterham S-type seats.


    Quote Originally Posted by SanderGA View Post
    is there going to be a NJMP gathering this year?

    Sure is. It is in October this year - we caught a lucky break by deciding to hold later in 2020. You are very welcome to join us - all owners or enthusiasts who want to own a seven are invited. Track is open again. They are looking forward to us coming back. Social distancing is working quite well. The breakfast and lunches are working ok as outside services by the pool area given there is still a ban on inside dining. Side by side instruction is banned in enclosed cars but I am working for approval for sevens on the basis we are totally open. Only thing we are still trying to work out is how to hold dinners - may end up catering at Garage Mahal as we can social distance some tables in there plus keep it warm at night. Details for now are here:
    http://www.usa7s.net/vb/showthread.p...ober-8-10-2020
    Mike
    2010 Caterham CSR with Cosworth 2.3 Duratec
    2018 Caterham 420R with 2L Duratec 210hp at Donington UK
    1975 BMW CSL Group 4 (restoration finished - track set up time)
    1977 Holden Torana "A9X" (awaiting restoration)
    1985 Holden Commodore SS Group A (suspension restoration)
    1985 Holden Commodore Group A (suspension set up)
    1982 Ferrari 400i (radiator replacement)
    1965 Ford Mustang Fastback "Holman Moody"
    1992 Ford Escort RS Cosworth WRC (dyno time)
    1990 Range Rover 2 door Classic
    and another project car coming....

  10. #10
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    The valve cover color is not a reliable indication of the Swindon state of tune. I bought my car from the original owner who bought the kit from Sevens and Elans and who kept all of the original paperwork. 1993, H in the 7th digit, 218HP Swindon engine with red cover, QR Racetech wheel as an option, specified to delete seats and delivered with standard bench type seat as owner was tall. As Mike has said though, just enjoy the car.

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