eric Posted February 23, 2002 Share Posted February 23, 2002 I have a 1600 with a stage 2 head, 2 Webers 40 Dcoe and A2 cam. Who knows if it is some benefits to change the cam for a 234 or something else Link to comment Share on other sites More sharing options...
Chelspeed Posted February 23, 2002 Share Posted February 23, 2002 Someone who knows much more about crossflows than me will answer soon no doubt. My understanding is that the A2 is a late 1960's type of cam design whereas the 234 is a late 1970/80 type of design, if there was no useful development between 1960 and 1980 I'd be surprised. Link to comment Share on other sites More sharing options...
EFA Posted February 23, 2002 Share Posted February 23, 2002 The 234 is used in the 1700SS spec designed by Peter Cooper (now retired) when that engine spec was productionised by Caterham (Peter was latterly of Redline Components) The A2 is a softer cam which will liberate around 20bhp less than the 234. Fat Arn The NOW PROVEN R500 Eaterid=red> See the Lotus Seven Club 4 Counties Area Website hereid=green> Link to comment Share on other sites More sharing options...
Petrolhead Posted February 24, 2002 Share Posted February 24, 2002 Is that Eric from Ponteland? I used a 244 with great results. The light 7 can easerly handle this and doesn't feel as cammy as it would in a tin top. Still hanging around biggrin.gif Edited by - petrolhead on 24 Feb 2002 10:23:12 Link to comment Share on other sites More sharing options...
eric Posted February 24, 2002 Author Share Posted February 24, 2002 no, I am not sorry. What are the reasons why you prefer 244 Link to comment Share on other sites More sharing options...
cdg Posted February 24, 2002 Share Posted February 24, 2002 Eric, DO NOT put a 244 cam in your engine without pocketing your pistons first as their is not enough clearance with a standard piston. Even a 234 is marginal. You could use a set of high ratio rockers to give increased power with the A2 cam. Valve clearance should be OK, and you don't need to strip youir engine. Have a look at how well your head has been ported. There are huge gains to be had by having the head ported by a professional,(obviously to suit your chosen application) and again, you could leave your bottom end as it is. Chris. Link to comment Share on other sites More sharing options...
eric Posted February 24, 2002 Author Share Posted February 24, 2002 Chris I have a stage 2 UL head made by Burton power, what do you think of the quality of it (ported, gas flowed ...) Link to comment Share on other sites More sharing options...
cdg Posted February 24, 2002 Share Posted February 24, 2002 Eric, What valve sizes are they? Could you measure the inlet port diameter at it's narrowest point?(The best competition heads have a lot of material removed from the port). How wide are the valve seats and do they have a 3angle cut? Did Burton supply any flow figures with the head? That would tell you an awful lot. Email me off-line if you like. Chris. Edited by - cdg on 24 Feb 2002 21:52:14 Link to comment Share on other sites More sharing options...
Petrolhead Posted February 25, 2002 Share Posted February 25, 2002 Eric, Chris is correct. I used my 244 with Twin Cam flat tops pistons which had some material taken of the tops (Can't remember how much) The Twink pistons are stronger and much lighter. The reason I chose the 244 over the 234 was the better power delivery it gave. The engine was in a Westf1eld and pulled very well from 2000 rpm up. I feel that because the 7 is so light it can easerly handle a more radical cam. I am Roger is the best person to ask though as her is an authority on X Flows. Peter Still hanging around biggrin.gif Link to comment Share on other sites More sharing options...
eric Posted February 25, 2002 Author Share Posted February 25, 2002 Chris the only figures, I have are inlet valves : 1.555" Exhaust valves : 1.340" Do you think they are good figures Link to comment Share on other sites More sharing options...
cdg Posted February 25, 2002 Share Posted February 25, 2002 Eric, The exhaust size is fine, but the inlet is just standard GT size. I would go to the 1.625 inlet (available from Burton) and have the valve throats ported accordingly. This improves airflow by quite a large amount, and you should see a good improvement in torque and power. If you also use the high ratio rockers (you can find them used for about £100) you will get a powerful tractable motor with a useable power band for road driving and you won't have to remove your engine to do it. Alternatively you could sell your engine, and go for a good used 1700 which are available from time to time on this forum. I'm sure there are engine workshops in France that can install your larger valves- it really only requires a larger diameter seat cutting (easy even with a portable seat cutter) and some gentle blending for a smooth approach to the seat area. Valves are about £10 each from Burton. Chris. Link to comment Share on other sites More sharing options...
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