AMMO Posted December 2, 2001 Share Posted December 2, 2001 Anyone please got valve lift, duration and timing for the 1700 BDR as fitted by Caterham? Valve sizes would also be nice. Do they really make 170 bhp? Just curious. AMMO Link to comment Share on other sites More sharing options...
Roger King Posted December 2, 2001 Share Posted December 2, 2001 Ammo, In our experience a Caterham supplied 1700ccm BDR makes around 155bhp. If extra cylinder head work is carried out the figure will rise to the high 160s and if you go up a size on the valves you should achieve 170bhp. Dnyo figures vary considerably and our work was done on a bed that is known for it's pessimistic figures. It is really very difficult to say that any figures are 'accurate'. I've got the cam figures at work (not in my head), but the BD3 is not a particularly hairy profile. A lot of driveability problems with standard BDRs are attributable to the strange carburettor spec and can be completely eliminated without touching the cams. Don't know if this is why you are asking, but lots of owners think that their problems are down to the cams when they actually have nothing to do with it. Link to comment Share on other sites More sharing options...
oilyhands Posted December 2, 2001 Share Posted December 2, 2001 Pete Jones at Jondel did the head prep on the original 1700 BDR kits as supplied to Caterham, he maintains they made pretty close to the full 170BHP, BD3s are pretty tame by comparison with cams for 8 valve engines, but when you see K series engines producing 120BP+ per litre on 280 degree cams.. perhaps not. BD3 lift 8.58mm 290 degrees 35/75 75/35 (LC 110) The quoted timings are for a lobe centre of 110, but I've seen better results with the inlet cam advanced 4 or so degrees. I think valve sizes were 31mm / 24.5mm, but that's from memory. Oily Edited by - oilyhands on 2 Dec 2001 23:38:44 Link to comment Share on other sites More sharing options...
AMMO Posted December 3, 2001 Author Share Posted December 3, 2001 Thanks guys It's a pretty well known fact that manufacturers lie about their horsepower figures. I was just trying to work out how much power you need to accelerate you from 0-60 mph in 5 seconds. The cam information would help me make some assumptions about horsepower per litre. My owners manual states for the 1700 HPC a 0-60 time of 4.9 seconds and a top speed of 120 MPH. These are exactly the sort figures I have in mind for my car. Are the speed figures realistic or are these slightly doctored as well? AMMO Link to comment Share on other sites More sharing options...
edmandsd Posted December 3, 2001 Share Posted December 3, 2001 These engines are at a seriously low level of tune with lots more available. I've got a pair of BLF17 cams if you're interested which are the original Hart420R profile but you'll probably find they're too wild for your application. Link to comment Share on other sites More sharing options...
oilyhands Posted December 3, 2001 Share Posted December 3, 2001 Dave's right when he says there is a wide selection of cams available, BD3s are a fast road cam, I've used F1s before on a BD and they are pretty hot, but engine life is considerably reduced. If you want something a bit warmer the L1/BD3 combination works very well for road use. Up from that L2s are quite warm at 302 degrees, the next steps would be (in ascending level of scaryness) L1s (306/10mm), DA10s(312/10mm), BD4s(316/10mm) , DY1s(317/11mm), DA12s (322/11mm) ,F1/EA1 (324/10/11mm) and DA1s (326,10mm), there are some PH4 and PH5 cams as well at 314 and 324 degreees/11mm. All of these are going to lose you some grunt in the midrange, L2s are a pretty good compromise, and I've seen L1/DA10 inlet with L2 exhaust used in combination too, they work pretty well, the lobe centres are fairly close together at 102 degrees. Oily Edited by - oilyhands on 3 Dec 2001 15:00:26 Link to comment Share on other sites More sharing options...
AMMO Posted December 3, 2001 Author Share Posted December 3, 2001 Sorry, I may have given the wrong impression. Have removed the old Crossflow and am fitting an 1800 Zetec (poor man's stroked BDR?). I've fitted bigger valves (33/29 on stock seats, 1 mm up on standard)and FZ2001 cams. Just trying to guesstimate if this combination will give me performance comparable to the HPC cars. I think it will be slightly better but being a pessimist will wait and see what the dyno says rather than make over-optimistic estimates. The ported head has enough flow for well over 200 bhp but the cams are mild with only 262 degrees duration and the compression is only 10.6:1. I will be running 45 Dellortos with 36 mm chokes initially with 45 mm throttle bodies later on. Should have it running by the weekend. AMMO Link to comment Share on other sites More sharing options...
elie boone Posted December 3, 2001 Share Posted December 3, 2001 AMMO, horsepower is one thing but you should also compaire the torque graf. between the two engines. If you want a 0-60 time of 4.9 get a g.box with long 1st gear or put the car on a diet. Link to comment Share on other sites More sharing options...
AMMO Posted December 3, 2001 Author Share Posted December 3, 2001 Elie I agree about the gearing and the diet. Maybe next year. That's the fun of the Caterham, there are always little jobs and those extra modifications to look forward to. AMMO Link to comment Share on other sites More sharing options...
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