Rocket_Rabbit
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| posted on 6/12/11 at 11:08 AM |
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N/A Cosworth Power
So I have a Cossy engine that has had all the trimmings done to it:
SBD Tapered ITBs
Jondel race head that has been P&P'ed to a 1/1000th inch of its life Big valves, solid rockers, uprated valve springs etc etc
Custom cams
Wossner rods
Cosworth slipper pistons
Dry sump
Omex 600 management
It makes 232bhp @ 7400rpm with 7900 limit
I come from Honda engines so 7900 isn't a lot and I know I can get more by adding some revs.
Perhaps the best thing about the YB is that it is a good deal oversquare and, as such, piston velocities are low per given rpm compared to a normal 2
litre engine.
I'd rather not stroke it because of the cost - taking it to a 2.3 would mean looking at the £3k mark.
I was hoping that a set of cams would be doable.
Anyone any experience?
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mcerd1
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| posted on 6/12/11 at 11:41 AM |
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you could take it to 2090cc with 93mm pistons if your sticking with NA, or maybe even 94mm if your brave  - that'll add a fair bit of torque
and some power
(I've got 93mm forged ones for my pinto on cossie rods - they should be good for 8000 - 9000 rpm)
if the heads got solid followers in it you should be able to let it rev a bit more than that - the des hammill pinto book covers some of the
options/limits
[Edited on 6/12/2011 by mcerd1]
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MakeEverything
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| posted on 6/12/11 at 11:57 AM |
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Google cosworth YB tuning. There's info on cams there.
http://www.modifiedmonsters.com/t315-tuning-the-yb-cosworth-engine
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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Oddified
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| posted on 6/12/11 at 12:04 PM |
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You've got the right bit's in the engine, so it's down to cam's and rev's. The rev limit of 7900 is relatively low for
the engine spec, but it depends on the 'custom cams'. Do you know what spec/timing/duration they actually are?, if they're
mild/medium then 230/7900 is about right.
I have 93mm accralite pistons in mine, Kent L1/BD3 cams (which is a middle of the road set up), rev limit of 8000 and it makes around 220/230bhp.
I'm planning on swapping the exhaust BD3 to an L1 and then raising the rev limit to 8500 or 9000 rpm which will make it far more exciting 
Ian
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Rocket_Rabbit
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| posted on 6/12/11 at 01:15 PM |
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Thanks for the replies!
I'll try and dig out the receipt for the cams to see what they are.
It idles at 800rpm so they can't be that lairy!!
I was thinking peak power at 8000 and 8500 maximum. I'd like to hope that offers some reliablility too.
As for the piston setup, i'll stick with the standard displacement. It's plenty torquey enough already with 175ft/lbs and the cost of
getting it done would be high!
I'll have a look at that Des Hamill book too 
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Craigorypeck
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| posted on 6/12/11 at 02:13 PM |
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with those ingredients your engine will scream to 9000.. easily.
must be cams if it wont make power beyond 7400
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Rocket_Rabbit
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| posted on 23/12/11 at 01:22 AM |
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Took some pictures and did some research.
Apparently, the crank is a pinto crank. Obviously not as strong as Cossie crank, but lighter which is helpful.
Des says that it's good for 8500rpm which is fine, I was thinking 8500 anyway.
But check the cam picture out below. To me it looks extremely mild in terms of duration
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John Bonnett
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| posted on 23/12/11 at 06:53 AM |
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quote:
Originally posted by Rocket_Rabbit
So I have a Cossy engine that has had all the trimmings done to it:
SBD Tapered ITBs
Jondel race head that has been P&P'ed to a 1/1000th inch of its life Big valves, solid rockers, uprated valve springs etc etc
Custom cams
Wossner rods
Cosworth slipper pistons
Dry sump
Omex 600 management
It makes 232bhp @ 7400rpm with 7900 limit
I come from Honda engines so 7900 isn't a lot and I know I can get more by adding some revs.
Perhaps the best thing about the YB is that it is a good deal oversquare and, as such, piston velocities are low per given rpm compared to a normal 2
litre engine.
I'd rather not stroke it because of the cost - taking it to a 2.3 would mean looking at the £3k mark.
I was hoping that a set of cams would be doable.
Anyone any experience?
Pete Jones at Jondel built my n/a YB and the engine was superb. It was built to their 250bhp spec and was utterly tractable pulling like a train from
1000rpm. A lad, a Mr Koukanis (sorry not sure about the spelling) with a yellow Westfield using a Jondel engine built to the same spec did amazingly
well in Sprints a few years ago.
Pete knows just about all there is to know about building these engines, is very approachable and helpful and he would be my first port of call.
regards
John
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mcerd1
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| posted on 23/12/11 at 10:54 AM |
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quote:
Originally posted by Rocket_Rabbit
Apparently, the crank is a pinto crank. Obviously not as strong as Cossie crank, but lighter which is helpful.
the cossie crank is a strait swap if you fancy an upgrade - only real difference is that the flywheel has 9 bolts instead of 6 (which means no need to
dowel the flywheel )
burtons sell nice light steel flywheels in pinto or cossie size and they can be drilled to suit either crank - I've got a pinto sized one
(5.5kg) on my cossie crank with ARP bolts 
I'll admit its not the cheapest option but I think its worth it for the peace of mind...
[Edited on 23/12/2011 by mcerd1]
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Craigorypeck
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| posted on 23/12/11 at 10:57 AM |
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it looks like it has ford stamped on the cams?? cant really see but if it is they may be standard turbo cams? most aftermarket ones be it kent/newman
etc wont be stamped "ford" would they??
tbh they look pretty standard, (maybe a regrind) looks to have a tad more lift, cant be sure..
any idea what the the lifters are? solid or hyd
HTH
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Craigorypeck
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| posted on 23/12/11 at 11:03 AM |
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quote:
Originally posted by mcerd1
quote:
Originally posted by Rocket_Rabbit
Apparently, the crank is a pinto crank. Obviously not as strong as Cossie crank, but lighter which is helpful.
the cossie crank is a strait swap if you fancy an upgrade - only real difference is that the flywheel has 9 bolts instead of 6 (which means no need to
dowel the flywheel )
burtons sell nice light steel flywheels in pinto or cossie size and they can be drilled to suit either crank - I've got a pinto sized one
(5.5kg) on my cossie crank with ARP bolts
I'll admit its not the cheapest option but I think its worth it for the peace of mind...
[Edited on 23/12/2011 by mcerd1]
Same as... had the cosworth flywheel machined down and the pinto ring gear put on. cheap
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mcerd1
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| posted on 23/12/11 at 11:59 AM |
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quote:
Originally posted by Craigorypeck
Same as... had the cosworth flywheel machined down and the pinto ring gear put on. cheap
^^ I wanted a lighter flywheel too though and I've heard more than enough horror stories about lightened cast flyweels 
as some else put it to me: 'its alot of money for a flywheel / bolts - but its alot cheaper than new legs! '
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Rocket_Rabbit
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| posted on 23/12/11 at 12:02 PM |
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quote:
Originally posted by Craigorypeck
it looks like it has ford stamped on the cams?? cant really see but if it is they may be standard turbo cams? most aftermarket ones be it kent/newman
etc wont be stamped "ford" would they??
tbh they look pretty standard, (maybe a regrind) looks to have a tad more lift, cant be sure..
any idea what the the lifters are? solid or hyd
HTH
I tend to agree with you regarding the cam profile. The lift does look increased but the profile does look remarkably turbo like.
According to Des, standard lift is 8.5mm, but I am not sure how to measure this.
I was under the impression that Hydraulic lifters don't offer anything past 7500rpm, so i'd say I have solid. Is there anyway to check
other than removing the cams?
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Craigorypeck
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| posted on 23/12/11 at 01:09 PM |
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measure the height of the lobe top to bottom and subtract the radius.. should give the lift..
Cams will have to come out to see if the lifters are shimmed.
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Rocket_Rabbit
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| posted on 23/12/11 at 01:35 PM |
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quote:
Originally posted by Craigorypeck
measure the height of the lobe top to bottom and subtract the radius.. should give the lift..
Cams will have to come out to see if the lifters are shimmed.
right, I have 11mm lift which means without doubt I have solid lifters and
uprated springs!
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John Bonnett
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| posted on 23/12/11 at 01:45 PM |
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Rocket_Rabbit
U2U sent
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