Im just trying to get my head around camshafts and more to the point what i need to achieve at least 250bhp on my 2.3 duratec.
im looking at the Cosworth YD0859 and YD0860 which apparently give 220bhp (whether that's 220 on a 2.0 or 2.3 i'm not sure)
290° Duration
11.3mm lift
118° ATDC Timing
Does this mean that they will give 220bhp on an otherwise standard engine?
with high comp pistons, TB's, exhaust, Emerald could i still hit 250BHP or would i need something a little more aggressive?
Last edited by 5tox; 21-07-2019 at 20:59.
Give Paul Gardner a call, he'll tell you exactly what cams you need to achieve that figure on a 2.3 Duratec. He possibly will have will have a pair of cams in stock to supply you with.Originally Posted by 5tox
Research the Kent DTEC35 cams, I have used these in a 2.0 and now a 2.4 and are excellent all round camshafts
Well i managed to win a nearly new set of cosworth camshafts yd0859 (11.3mm lift) and yd0860 (9.95mm lift) for £165 off fleebay which come as a complete surprise, thought they would have gone for a lot more.
Im looking at a set of cosworth yd0093 valve springs which come in at about £20 each which will accommodate an 11.5mm lift.
My question is... could i get away with only buying 8 as opposed to 16, the cosworth exhaust cam has a 9.95mm lift so could i get away with using the standard duratec springs?
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valve springs are not just about accommodating lift, cams with more aggressive profiles need stiffer springs even if they dont lift any higher..................
If it was my engine build I would not use std springs unless you are going to drive it like a Granny.
Cheers guys, i shall buy a complete set then
Hello,
First of all sorry for old topic.
Could I ask you for a help? I have just mounted set of 220bhp camshats in my fiesta st150. But I cannot find informations if those are compatible with standard pistons. Did you run those camshafts with standard pistons?
I very apreciate ane help
Cheers!
A little more information about the camshaft make and specification would help before anyone can comment, just saying they are 220 bhp cams is not enough.
I'm writing about cams which this topic concerns:
Cosworth YD0859 and YD0860
R400 220bhp spec camshafts
Inlet:
Duration 290dg
11.3mm max lift
118dg ATDC timming
Exhaust:
Duration 266dg
9.95mm max lift
108dg BTDC timming
Unfortunately that is all I have about them, I had written to Cosworth asking them to confirm or deny if those can be used with standard pistons
cosworth may not give you an answer, tolerances and exact timing positions mean they might be ok in one engine and not in another.
if you have already fitted them you can check your self, piston to valve clearance gets tightest around TDC, so working around TDC check to see how much further you can open the valves before they hit the pistons
Thank you for answer, could you tell me if the risk of collision increase when we hit high rpms? I mean when the space between piston and valve is small but engine works properly on low rpms and if there is a risk that valves will start to float at high rpms? Springs are replaced to the ones which are dedicated to 11000rpm maximum. By high rmps I mean standard red line - 7200 rpms. I have done trials, engine is working correctly, but right now I'm operating only up to 3000 rpms.
Those cams are ones for the Caterham R400's, maybe they could supply you with more information about them.
You really need to know what lift the cams have @ TDC. Never take chances with valve to piston clearance, any contact with valves and pistons and it's game over, a big mess.
yes the risk of collision goes up as revs go up, but its not just down to valve springs. As revs go up con rods stretch and get longer so pistons get closer to the head and therefore valves. typically from 0 rpm to 7500/8000 rpm the rods will stretch about .030" or .75mm, heat will also make valve heads and piston crowns thicker, further reducing clearance. so just because your engine clears @3000 rpm it doesnt mean it will still clear @7500. this is why when you do a build you should check you have 0.080- 0.100" or 2-2.5mm clearance
Thank you guys, I really apreciate your help, I will wait for more specific information from cosworth, as you said most important is to know what lift occurs at TDC, soon I get info I will share it, maybe it will be helpful to someone at the future
Cheers!
Last edited by k0wal; 16-11-2020 at 20:41.
I have recieved respond from Cosworth:
"We have run that specification of camshaft with slightly higher compression ratio pistons so would expect the standard pistons to have clearance.
If you have any concerns our recommendation would be to check the valve to piston clearance using modelling clay during the build process."
Still waiting for values of their clearance I have asked for but it seems to be ok if valve head was not skimmed before.
cosworths slightly higher compression pistons might have valve cut outs to clear bigger cams, so just because you have standard pistons doesnt mean you have enough clearance. the amount of clearance needed doesnt actually much if any from engine to engine you should be looking at an absolute minimum of 1.5mm in 2.0mm exhaust, but preferably 2 and 2.5mm
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