Lotus Elan

Con.rods

PostPost by: Petter Hval » Sun Jun 22, 2008 10:02 pm

I have a set of new GAF forged narrow journal con rods
( made for a turbo engine) wich I intend to use in a new
1800cc engine. What is the max safe rpm for thise rods and wh0 is
the produser of the rods.
Petter
Petter Hval
Second Gear
Second Gear
 
Posts: 52
Joined: 09 Apr 2004

PostPost by: Dag-Henning » Mon Jun 23, 2008 8:56 am

Petter , they are Farndon. 8k - 8.5k would be OK, provided you use proper bolts..... :wink:

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 » Mon Jun 23, 2008 12:42 pm

Any forged rod worth its price should be good for 9000 rpm plus with the right rod bolts, otherwise its not worth the money.

An 1800 engine will get to the head breathing limit around 7000 rpm and 200 hp so rods should not be a real issue. I would be more worried about the block your using to get 1800 cc as an 85 mm bore and extra long stroke in a standard block is starting to get fragile much more so than the rods.

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

PostPost by: Evan Carpenter-Crawford » Mon Jun 23, 2008 6:47 pm

Following on the 1800cc part of the post...

Have you seen the 2.2L Lotus Twincam John Wilcox produces?
This is a BDG block with 90.335mm cylinder bore and an 84mm Stroke.
I wonder how this capacity would work with the flow available from the head? (what rpm for peak torque? redline?)

Probably also requires a hood bulge or modified engine mounts in a baby elan...

Anyone have experience with John Wilcox and/or this capacity in a twincam?

...since I found this its been on my personal "lunatic fringe" modifications wish list, albiet from a US engine builder. (the exchange rate is a little unfavorable for us yanks at the moment !)

Evan CC
Evan Carpenter Crawford
1969 FHC 8624
Evan Carpenter-Crawford
First Gear
First Gear
 
Posts: 45
Joined: 12 Sep 2003
Location: michigan

PostPost by: Petter Hval » Mon Jun 23, 2008 8:53 pm

The engine will be based on the 711M block with 83,5 mm bore and 82mm stroke (QED EN40 steel crank with 130,3 mm rods)
Thanks Dag - I`ll go for the ARP bolts.
Petter
Petter Hval
Second Gear
Second Gear
 
Posts: 52
Joined: 09 Apr 2004

PostPost by: garyeanderson » Thu Jun 26, 2008 5:58 pm

Evan Carpenter-Crawford wrote:Following on the 1800cc part of the post...

Have you seen the 2.2L Lotus Twincam John Wilcox produces?
This is a BDG block with 90.335mm cylinder bore and an 84mm Stroke.
I wonder how this capacity would work with the flow available from the head? (what rpm for peak torque? redline?)

Probably also requires a hood bulge or modified engine mounts in a baby elan...

Anyone have experience with John Wilcox and/or this capacity in a twincam?

...since I found this its been on my personal "lunatic fringe" modifications wish list, albiet from a US engine builder. (the exchange rate is a little unfavorable for us yanks at the moment !)

Evan CC


Hi Evan

A tall deck Twin Cam is about 7/16 of an inch higher (when built to max height of a 711 block) weather it has a 84 mm stoke crank or 77.62 mm. This will fit under the bonnet of a Elan with out doing any bulge or any changes to the engine mounts. At the most, you may have to remove the bonnet insulation pad (if your Elan still has it). All it takes is cubic Dollars to build a Colossus Cubic Centemeter Twin Cam (90.4mm x 84mm = 2156cc). Just give Moldex, Carrillo, JE, and Cosworth a call and leave them your credit card number.

Gary
User avatar
garyeanderson
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 3128
Joined: 12 Sep 2003
Location: Massachusetts, U.S.A.

PostPost by: msd1107 » Fri Jun 27, 2008 4:32 am

Petter,

What pistons are you using?

That 130.3 mm con rod seems awfully long together with the 82 mm stroke, even in a tall block.

Oftentimes on a 77.6mm stroke tall block, a 125.2 mm con rod is used.

Of course, pistons can be specified with a variety of piston pin locations, so that seems to be what was done here.

David
1968 36/7988
User avatar
msd1107
Fourth Gear
Fourth Gear
 
Posts: 854
Joined: 24 Sep 2003
Location: Hollywood, CA USA

PostPost by: garyeanderson » Fri Jun 27, 2008 9:13 am

msd1107 wrote:Petter,

What pistons are you using?

That 130.3 mm con rod seems awfully long together with the 82 mm stroke, even in a tall block.

Oftentimes on a 77.6mm stroke tall block, a 125.2 mm con rod is used.

Of course, pistons can be specified with a variety of piston pin locations, so that seems to be what was done here.

David
1968 36/7988


Hi David
The block height is 8.21 inch or 208.53 mm for a 711 block
when you subtract the rod length of 130.3
it gives you 78.23 mm
take away half of the 82 mm stroke or 41 mm and you are left with
37.23 mm for the compression height. Converted back to inches equals
1.4657 inch pin or compression height which is readily available off the shelf from Dave Bean and I am sure all of the others. No skimming needed to weaken the block, it sounds perfect to me...

Gary
User avatar
garyeanderson
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 3128
Joined: 12 Sep 2003
Location: Massachusetts, U.S.A.

PostPost by: Petter Hval » Sat Jun 28, 2008 8:04 pm

David
I`m going to use JE custom pistons
Petter
Petter Hval
Second Gear
Second Gear
 
Posts: 52
Joined: 09 Apr 2004

PostPost by: rgh0 » Sun Jun 29, 2008 3:09 am

Hi Evan

My twin cam simulation says you get around 190hp at 6000 to 6500 rpm and an impressive 180 ft-lbs of torque at 4500 rpm from a 2.2 Wilcox twin cam.

This simulation includes big bore exhaust headers, 45 DCOE's with 36 mm chokes, 10:1 comp ratio, 0.44 inch lift cam with 280 degrees seat to seat, and a top quality McCoy CNC ported head.

I have seen dyno results of big capacity twin cam engines that show a little over 200hp though I cant testify for the accuracy of the dynos involved.

In general I believe about 190 to 200 hp is what you can achieve with the twin cam head even for the most exotic twinks in terms of 9000 rpm revs or 2.2l capacity. You dont really make the most of the 90mm bore in a 2.2L engine. If designing the head from scratch you could have spread the valves further apart and had bigger valves and ports to breath better with this sized bore.

The torque of a 2.2L in a road going Elan would be fantastic provided the rest of the drive train was rebuilt to stand it eg uprated clutch assembly, Quaiffe gear box internals and LSD, CV drive shafts and strengthened diff and axle hub shafts.

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

PostPost by: steveww » Wed Jul 02, 2008 8:58 am

The Wilcox 2.2l twinc is on my ultimate wish list too :?

As Rohan says the torque available from such a motor in the light weight Elan would provide a lot of fun, provided the rest of the drive train did not just snap.
User avatar
steveww
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1838
Joined: 18 Sep 2003
Location: Northamptonshire, England

PostPost by: elandoc » Mon Jul 07, 2008 1:58 am

Is the BDG block alloy?

Patrick
67 S3 DHC - The world's most expensive Elan
64 Morris Cooper S (now sold)
85 Ferrari 308 GTSi QV
79 Ferrari 400i
68 Lotus Europa S2 (in boxes - wanna buy it?)
50 Riley 21/2 Litre (now sold)
65 Lotus Elan S2 (in boxes, soon to be a lightweight)
elandoc
Second Gear
Second Gear
 
Posts: 113
Joined: 02 Nov 2004
Location: Gold Coast, Australia

PostPost by: rgh0 » Mon Jul 07, 2008 2:13 am

Patrick
Yes the blocks you can get now are alloy - and at a cost that would suit the worlds most exepnsive Elan

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

PostPost by: elandoc » Mon Jul 07, 2008 4:21 am

I did toy with the idea...
67 S3 DHC - The world's most expensive Elan
64 Morris Cooper S (now sold)
85 Ferrari 308 GTSi QV
79 Ferrari 400i
68 Lotus Europa S2 (in boxes - wanna buy it?)
50 Riley 21/2 Litre (now sold)
65 Lotus Elan S2 (in boxes, soon to be a lightweight)
elandoc
Second Gear
Second Gear
 
Posts: 113
Joined: 02 Nov 2004
Location: Gold Coast, Australia

Total Online:

Users browsing this forum: No registered users and 2 guests