camshaft big valve weber

[umbyfer]

Hello,

I am looking for as much as possible advises to set up my big valve engine weber carbs of elan sprint.

I use the car on the road only and for regularity race where I need more torque at low rpm in first/second gear instead of high rpm as on race version. (My standard use is from 1500/2000 to max 4500 rpm; over 4500 just for short and few times, ... some takeovers).
The previous owner told me that he installed race cams, but I don't know nothing else. I am opening the engine in the next days and I can check the actually cams data. Any info helping me to recognise actual cams would be appreciate.

Which was the original standard cams and valve set up for elan sprint big valve for road use?

Please confirm or not and add missing important data for standard cams:
Camshaft D type with two rings
valve 26?/66?/66?/26?
diameter 0,360
lift ???
other important data ???


Thank you for any help.

Regards,
Umberto Ferrari
Elan Sprint Gold Leaf '71
7108000193K
Modena-Italy

[types26/36]

Umberto, you have yahoo mail.

[Jolly Jumper]

(My standard use is from 1500/2000 to max 4500 rpm; over 4500 just for short and few times, ... some takeovers).

Umberto,

why only 4.500??? You are missing the best bit!
Try and go higher, the engine can take it. It is safe up to 6.500.
If you don't want to rev the engine, you could throw away the standard Big Valve Cam and go for a different design with the Cams timed accordingly. Smaller Venturis (say 30 instead of 33) will also improve low speed torque. But you will miss out on some fun. The Twin Cam has good torque, but it still a rev hungry engine.

Cheers
Jolly

[umbyfer]

Hi Jolly,

thank you for the info. Actually I don't know wich kind of cams I have. The previous owner told me to have installed some race cams... I am opening the engine in next days to repair water pump. I will check.

I think the standard cams are ok... for my needs. I don't need special cams... I use the car on the road and for regularity race where I have to drive in 1st gear for 30-50 meters with a prompt engine.

Do you have all the data of standard cams? Lift, diameter, .... others ... in order to know what I have now.

Thank you,
Umberto

[Jolly Jumper]

Hi Umberto,

I think you misunderstood me. What I was trying to say is: The Big Valve Engine (and the other Twin Cams as well) are designed to rev much higher than 4.500. If you want to enjoy the engine, you must go higher. It does not make any sense to restrict the revs on a 1600cc Twin Cam engine to 4500.

My advise is you fit the standard Big Valve cams and Sprint Spec Venturis and forget the rev limit of 4.500. You will then have a nice engine with good torque and good performance. You don't need high-horsepower race-cams or high-torque cams. Standard cams are just fine, the rest is down to cam timing and Venturis. And you must use the engine as intended by the engineers, which means make use of the available revs.

[umbyfer]

Hello,

I understand: this is exactly what I need; a good and uniform performance from 1500/2000 to the upper limit. I don't want to restrict at 4500; I sed 4500 becouse usually I don't drive fast and so I remain below 4500 rpm. But I know that over 4000 is great !

I check wich cam i have and in case they are race cam I go buy new standard original cams; may be I change the ratio of the first gear in order to work at higher rpm with perfect torque and power... in case I need something more at very low speed in first gear when I am in regularity race.

Thanks a lot for the clear explanation.

Umberto