Lotus Elan

Stock Motors

PostPost by: Elanspit » Thu Dec 28, 2006 11:40 pm

I have recently upgraded from racing a TR4 and Spitfire to a Series 2 DHC. One wag noted that "After racing an Elan, the TR4 will feel positively agricultural."

He was right: the car is a delight!

The motor is 1780 cc, and is obviously not stock. For a variety of reasons (including being able to legitimately race in CP here in the Western US), we are taking it back to 1600 cc.

I am having some second thoughts, though, as I am picking up a drift that a lot of Elans no longer run 1600 cc.

Question for the denizens of this board: What percentage of Elans are raced with a 1600 cc motor?

Many thanks.

Tom
1965 Lotus Elan #03
1967 Triumph Spitfire #54
Elanspit
New-tral
 
Posts: 7
Joined: 28 Dec 2006

PostPost by: Frank Howard » Fri Dec 29, 2006 2:04 am

Elanspit wrote:One wag noted that "After racing an Elan, the TR4 will feel positively agricultural."


Tom,

99% of what I know about cars was learned during ownership of my first car, a 1964 TR-4. One reason the TR-4 may feel agricultrial is because the engine is out of a Massey Fergeson tractor (2138 ccs).

I realize you are interested in the displacement of racing Elans but just for your information, the stock Elan displacement is 1558 ccs from Series 1 through the Sprint. (The first 20 cars or so that were 1500 don't count as they were recalled and exchanged by the factory.)

Hope this helps.
Last edited by Frank Howard on Fri Dec 29, 2006 8:59 pm, edited 1 time in total.
Frank Howard
'71 S4 SE
Minnesota
Frank Howard
Fourth Gear
Fourth Gear
 
Posts: 994
Joined: 30 Mar 2004

PostPost by: rgh0 » Fri Dec 29, 2006 6:23 am

Tom

I guess what capacity you run depends on what modifications your local racing regulations allow and how strictly they are enforced. In Australian historic racing I am allowed a maximum 1 mm over bore from standard but must retain the original stroke. This limits me to taking the motor from its standard 1558 cc to 1600 cc. The historic eligibility officers here are very strict with their enforcement also.

In Europe the FIA historic regulations are similarly limiting I believe but how strictly they are enforced is questionable as a racer aquaintance of mine back from a European trip recently said most of the twin cams he saw in historic race cars were based on 1600 long stroke blocks so what capacity they are is anybodies guess!!!

regards
Rohan
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 7515
Joined: 22 Sep 2003
Location: Melbourne, Australia

PostPost by: Dag-Henning » Fri Dec 29, 2006 8:36 am

Tom / Rohan, - I believe there are a variety of local regulations around, but I would claim that the vast majority of seriously built racing Elans in Europe are built according to Fia App. K. As Rohan says, that means std. stroke, and max 83,65 mm bore. ( max 1,2 mm increase, and within class limit) As a fact, the only block allowed under these regulations is the 120E, with the "round" caps.
Would be interesting to hear where abt in Europe most of the TCs were tall block conversions. ( UK club-racing maybe ?)

Dag
Elan S1 -64/ Elan race-replica 26R / Works Escort TwinCam -69/ Brabham BT41 Holbay
User avatar
Dag-Henning
Third Gear
Third Gear
 
Posts: 461
Joined: 30 Sep 2004
Location: Oslo, Norway

PostPost by: rgh0 » Fri Dec 29, 2006 1:05 pm

Dag

I presumed he was talking about FIA historic racing rather than UK club racing but you may be correct. What ever given the guys interests he was probably looking more at open wheel racers or sports racing car classes rather than App K Elans.

regards
Rohan
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 7515
Joined: 22 Sep 2003
Location: Melbourne, Australia

PostPost by: Elanspit » Fri Dec 29, 2006 4:34 pm

Gentlemen -

Thanks for your prompt observations. I have enjoyed reading many of your posts, and am most impressed with your knowledge of Elans.

A few additional thoughts:

1. Frank, you are, of course, correct. We are doing a 1558 +.06 overbore, which is the max our club (VARA) will allow.

2. Rohan and Dag, it is interesting to hear how strict your enforcement is. At least with the two groups I run with (VARA and SCCA), they seem to rely on honor (via a pre-season written declaration of specs) and common sense observation at tech and during the season.

My Elan was apparently raced by prior ownership in CP and posed as a 1558 motor, even though it was 1780; obviously, that was not appropriate. When I bought the car, I immediately declared it CP3 (where it runs against 2.4L 911s), as I do not believe in bending the rules (with apologies and no offense meant to Mr. Chapman, RIP).

Where enforcement comes into play here is after you post a string of victories that are too good to be true. I have not yet had the pleasure of that experience with the Elan, having just run the car twice (the Spit had 14 victories this year, and was the object of some carping by past class champions, to no avail, as it was properly prepared).

In any event, my die is cast and we are going to run a proper motor in CP. That probably means little chance of winning races overall, as the CP3 cars (e.g., 2.4L 240Zs and 911s) are simply too fast for a 1558 Elan except in the hands of a truly, truly good driver (which I am not).

However, we will do our best to bring at least some small additional glory to the marque by stomping as many 2.0L Porsches as we can in CP!

Thanks again for your insights.

Tom
1965 Lotus Elan #03
1967 Triumph Spitfire #54
Elanspit
New-tral
 
Posts: 7
Joined: 28 Dec 2006

PostPost by: cabc26b » Wed Jan 03, 2007 1:30 am

Tom,

I run in "CP" at 1600cc. if you have the benefit of running unrestricted wrt internal engine components ( most US groups allow leeway here ) you may only be giving away torque on that 1780 motor. If your check book can stand it call Mr. Veger and tell him not to spare the titanium. Kidding aside, you should be able to cob together a 1600cc twin cam using Formula car bits circa 1960's that will make 185 hp and be safe at 9000 rpm. Getting the other elements right is just as important as the motor - by this I mean the weight , brakes, tires, suspension, gearbox.


Get it mostly right and you will have a good time racing with the 2.0 liter stuff (BTW, I have found the alfa's much harder to deal with than the Porsche's) , and the under braked and non-suspended 5.0 liter cars and, and make it very difficult for a legit 2.4 liter car on a track with out a very long streight. ( My sense is the the 2.4 911's are not 2400cc and the 240z are not either.)

G










:shock:
cabc26b
Fourth Gear
Fourth Gear
 
Posts: 936
Joined: 21 Sep 2003

PostPost by: Elanspit » Wed Jan 03, 2007 6:39 am

G -

Thanks for the encouragement: I would be thrilled with 185BHP and running at 9 grand. I will post the dyno results when we are done with the rebuild.

And I hear you loud and clear on the other aspects of the car: its a lot more than just displacement.

Question: what kind of tires do you run? I am starting with Hoosier 205/60ZR 13s.

Hard to tell how good they are because, frankly, I am still learning to drive the car (e.g., I took the rear sway bar out because I felt uncomfortable with where the car would break away; will be doing skid pad work next month at Buttonwillow, CA to get more confidence).

The one thing I have noticed about the Hoosiers is that the Elan eats them a lot faster than the Spit does!

Tom
1965 Lotus Elan #03
1967 Triumph Spitfire #54
Elanspit
New-tral
 
Posts: 7
Joined: 28 Dec 2006

PostPost by: rgh0 » Wed Jan 03, 2007 8:59 am

Tom / G

While I agree you can get 185 hp at 9000 rpm with enough time and money you can also get 175 hp at 7500 to 8000 rpm also out of a 1600cc.

The initial cost is about the same as the only difference is really the cam but the torque curve and power band is much wider in the 175hp engine and real life track times in an historic Elan will probably be quicker in the lower powered car unless you are changing diff and gear box ratios to suit each track.

The maintenance cost and time is also much lower as engine life at competition use is in the hundreds of hours rather than 10's of hours with a 9000 rpm motor and not as many things break off around the nose with the vibration if you limit maximum revs to less than 8500.


In my experience a well prepared Elan will have no problems with a 2 litre Porsche, be about even with a 2.4 litre Porsche and struggle to keep up with a well prepared 2.7 or 3 litre especially on the longer faster tracks.

240Z's you should also be able to beat or at least stay with if they are limited to their standard dual SU style carbs, if allowed to run triple Webers they get much harder to beat.

Alfas of any type also no problem.

All of the above comments apply to Australia historic production sports regulations which limit tyre size and type and restrcit light weighting of cars and restrict you to the original type number and make of carbs but allow unlimited internal engine mods. In general these limits suit as Elan better than most cars as it orignaly came very light and with good carbs and it benefits in comparision with many other cars from tyre width restrictions.

regards
Rohan
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 7515
Joined: 22 Sep 2003
Location: Melbourne, Australia

PostPost by: cabc26b » Sat Jan 06, 2007 7:24 pm

Tom,

I run Avon bias ply. mostly because they are what I know. I am curnetly using 7x22x13 ACB10. Some organizations frown on them, but since I am absorbing the tradional Lotus handicaping wrt to the group I am classed with , I don't pay much attention to tread pattern issues. I have contemplated using a 6.5x23x13 ACB9 to give the car some more leg. I have not heard good things about a rear anti-roll bar on an elan so you probably did the right thing by disconnecting it.

Rohan & Tom -

I could not agree more with Rohan on the Engine advice , while I refererence an achievable hp/rpm figure, what I run, is closer to what Rohan recomends. On RPM; I have an 8000 rpm tach and try to kepp the needle on the register. ( rev-limiter is set at 9000) At some time I may try to tune for more torque. I would add that drysump adds to the longevity and to run it if you can. Tire dia is my idea on range change ( I miss my hewland !!!)

The Alfa's present a problem because of the driver ( alfa guys seem to be of higher skill/knowledge/quality than myself ) All the z's are running six-paks and so will rocket down a streight. Plus here in the states you see 914/6's with up to 2.5 liters of displacement - and fast in the hands of a lot of people.
cabc26b
Fourth Gear
Fourth Gear
 
Posts: 936
Joined: 21 Sep 2003

PostPost by: Elanspit » Sun Jan 07, 2007 4:14 pm

C -

I hear you on the Zs: the guys in our club all run triple Webers.

Luckily, the Zs seem to have more than their share of mechanicals (at least it appears that way to me). Kind of like my old TR4 - I got rid of it partially because not only was I having too many DNFs, but so were the other TR4 drivers. Conversely, my Spit has been (knock on the Elan's dash) almost bulletproof for two seasons (only mechanical DNF was a broken spindle the week after I did an unannounced visit to the tire wall at Laguna Seca, so not really the car's fault).

Before I got the Elan, I tried to query any Elan racer I ran into as to the reliability of their car. I just asked the simple question: "Of every 10 race weekends, how many does the Elan complete?" The answers averaged out to about 9, which I consider pretty good and which made it that much easier to buy one. I have just done two race weekends and two test days with the car, but so far it has completed everything just great (except for one day in Las Vegas where the battery croaked). Of course, I am keeping it under 8 grand which helps (and which is why I am reading your and Rohan's observations on engine life vs. revs with keen interest).

Tom
1965 Lotus Elan #03
1967 Triumph Spitfire #54
Elanspit
New-tral
 
Posts: 7
Joined: 28 Dec 2006

PostPost by: 1964 S1 » Fri Feb 02, 2007 4:05 am

Hello Tom, if you can win races in a Spitfire I believe you're a better driver than you realize.
Master the nuances of an Elan and you can beat anyone, but remember, Jackie Stewart had a difficult time racing Elans. Called it a sod of a car if I remember right.

Eric
1964 S1
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1496
Joined: 15 Sep 2003
Location: Hamilton County, Ohio

PostPost by: Elanspit » Fri Feb 02, 2007 5:22 am

1964 -

Thank you for your kind comments. I must say I am approaching driving the Elan with great humility. The car has over twice the BHP of the Spit and essentially the same weight. It is a different kettle of fish. I am not sure I agree with Mr. Stewart: I think it is a hell of a car. But I suspect it can get away from you in a flash, and I am being cautious in learning the limits of the car.

To me, the two key attributes to good race driving are courage and judgment. After only two weekends and two test days in the Elan, my judgment is telling me to check my courage for a little while!

I have complete confidence in the Spit and drive it accordingly, as I know how it behaves (except for a minor foray into a wall at Laguna Seca, but I digress. . . . ). I hope someday to have equal confidence in the Elan, but for now, I am erring on the side of caution until I get more seat time.

For any other racers out there, I have just completed the rebuild of the engine, taking it down from 1780cc to stock 1600 cc. The dyno results:

4500 RPM 103BHP 114 Ft/lbs
5000 RPM 111 111
5500 RPM 119 109
6000 RPM 143 119
6500 RPM 165 128
7000 RPM 166 119
7500 RPM 166 111
8000 RPM 164 103
8500 RPM 147 87

Will be testing it on a fast track (Willow Springs) in a couple weeks with a 3.9 back end vs. the old 1780/4.4 configuration. Feels like the two weeks before Christmas: having trouble waiting!

Tom
1965 Lotus Elan #03
1967 Triumph Spitfire #54
Elanspit
New-tral
 
Posts: 7
Joined: 28 Dec 2006

PostPost by: rgh0 » Fri Feb 02, 2007 9:32 am

Tom


Can you give a few more details of your motor specification so I can add your dyno data to my collection.

i.e.
If on an engine dyno what ancillaries connected and was car exhaust connected, if on a rolling road what factors used to estimate engine output
Cam seat to seat duration and gross lift
Valve sizes and any details of porting done such as minimum port size at valve seat and sizes at exit from head.
Carb choke sizes and jetting
Exhaust type and sizes of pipes and lengths
Compression ratio, fuel used and ignition timing max advance

regards
Rohan
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 7515
Joined: 22 Sep 2003
Location: Melbourne, Australia

PostPost by: Elanspit » Fri Feb 02, 2007 10:06 am

Rohan -

Will send you email.

Tom
1965 Lotus Elan #03
1967 Triumph Spitfire #54
Elanspit
New-tral
 
Posts: 7
Joined: 28 Dec 2006
Next

Total Online:

Users browsing this forum: No registered users and 1 guest