Longer conrods to Cosworth YB engine
03-11-2006, 08:07 PM
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Longer conrods to Cosworth YB engine
What kind of benefits is there to change longer conrods to cosworth engine? I'm going to buy new pistons and might change the conrods at the same time. Does longer conrod affect to the CR to be used? I mean that can the same ignition advance be used with longer conrod compared to the standard cosworth conrods?
03-11-2006, 08:23 PM
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Originally Posted by Fast Guy
How much longer are you thinking?
04-11-2006, 07:11 PM
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Up if someone else is interested. I'm not going to build high revving engine, since I want as much torque low down as possible and of course still power on the revs.
05-11-2006, 04:28 PM
#6
Those rods are intended for High CR N/A use
I think you will struggle to find pistons to work with them to keep the CR low enough to use in a turbo engine that you want to be making lots of torque low down (ie 8:1 or less)
I think you will struggle to find pistons to work with them to keep the CR low enough to use in a turbo engine that you want to be making lots of torque low down (ie 8:1 or less)
05-11-2006, 04:30 PM
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8mm longer rods
if you are thinking of changing rods then longer is better,
I would run the same comp ratio as sorter rods as there is not much to be gained from that, Only rod angle and reduced loading on bores.
If the link doesnt work search for Mad ade dyno results.
Mark
8mm longer rods
if you are thinking of changing rods then longer is better,I would run the same comp ratio as sorter rods as there is not much to be gained from that, Only rod angle and reduced loading on bores.
If the link doesnt work search for Mad ade dyno results.
Mark
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05-11-2006, 04:35 PM
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https://passionford.com/forum/viewto...31368&start=38
10th post down.
10th post down.
Ade's engine is 2lt 8mm longer rods,GT35 turbo with Internal and high flow wastegate flap and housing, Mad cams, Autronic SM2, and all the normal mods 
,
Mad Yum is 2.150cc hybrid GT35 external wastegate, Tubular manifold,MIS inlet, Mad cams, Autronic SM4 and CDI, and all the normal bits,
Rods similar to Yum but diff cams, RS500 inlet, GT40 turbo, Rods is more aimed at higher hp and rpm
.
Mark
,Mad Yum is 2.150cc hybrid GT35 external wastegate, Tubular manifold,MIS inlet, Mad cams, Autronic SM4 and CDI, and all the normal bits,
Rods similar to Yum but diff cams, RS500 inlet, GT40 turbo, Rods is more aimed at higher hp and rpm
.Mark
05-11-2006, 04:51 PM
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Originally Posted by chip-3door
Those rods are intended for High CR N/A use
I think you will struggle to find pistons to work with them to keep the CR low enough to use in a turbo engine that you want to be making lots of torque low down (ie 8:1 or less)
I think you will struggle to find pistons to work with them to keep the CR low enough to use in a turbo engine that you want to be making lots of torque low down (ie 8:1 or less)
05-11-2006, 04:53 PM
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Originally Posted by madevelopments
https://passionford.com/
8mm longer rods if you are thinking of changing rods then longer is better,
I would run the same comp ratio as sorter rods as there is not much to be gained from that, Only rod angle and reduced loading on bores.
If the link doesnt work search for Mad ade dyno results.
Mark
8mm longer rods
if you are thinking of changing rods then longer is better,I would run the same comp ratio as sorter rods as there is not much to be gained from that, Only rod angle and reduced loading on bores.
If the link doesnt work search for Mad ade dyno results.
Mark
05-11-2006, 05:11 PM
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Originally Posted by yrkesman
Originally Posted by chip-3door
Those rods are intended for High CR N/A use
I think you will struggle to find pistons to work with them to keep the CR low enough to use in a turbo engine that you want to be making lots of torque low down (ie 8:1 or less)
I think you will struggle to find pistons to work with them to keep the CR low enough to use in a turbo engine that you want to be making lots of torque low down (ie 8:1 or less)
Mark
23-01-2007, 04:42 AM
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Okay, I have now ordered 5mm longer rods and custom made CP pistons to suit them with 8:1 compression ratio. I hopefully get them in next few feeks so I can get back to my engine build.
Does anyone on here have experiences from using longer rods (let's say those 5-8mm longer versions)? How does it affect performance? Does the powerband go further up, any gues how much? Does it give more power all over the powerband? Just interested in these since I have read somewhere that it would make these things, but I have no idea how it works in reality.
Does anyone on here have experiences from using longer rods (let's say those 5-8mm longer versions)? How does it affect performance? Does the powerband go further up, any gues how much? Does it give more power all over the powerband? Just interested in these since I have read somewhere that it would make these things, but I have no idea how it works in reality.
23-01-2007, 08:20 AM
#16
The WRC engines in retsricted format, gain 15bhp by using longer rods, and an extra 500rpm rev range. I don't know anyone else that has done a direct back to back comparison....
The longer the rods, the less torque you get, but more bhp. However, 5mm is not going to make much difference either way. I would have done what Mark suggested and bought 8mm longer rods with the correct CP pistons, and I personally think that your c/r is too high and will require huge amounts of retard on the top line whilst flat out.
The longer the rods, the less torque you get, but more bhp. However, 5mm is not going to make much difference either way. I would have done what Mark suggested and bought 8mm longer rods with the correct CP pistons, and I personally think that your c/r is too high and will require huge amounts of retard on the top line whilst flat out.
23-01-2007, 08:55 AM
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Originally Posted by Mike Rainbird
The WRC engines in retsricted format, gain 15bhp by using longer rods, and an extra 500rpm rev range. I don't know anyone else that has done a direct back to back comparison....
The longer the rods, the less torque you get, but more bhp. However, 5mm is not going to make much difference either way. I would have done what Mark suggested and bought 8mm longer rods with the correct CP pistons, and I personally think that your c/r is too high and will require huge amounts of retard on the top line whilst flat out.
The longer the rods, the less torque you get, but more bhp. However, 5mm is not going to make much difference either way. I would have done what Mark suggested and bought 8mm longer rods with the correct CP pistons, and I personally think that your c/r is too high and will require huge amounts of retard on the top line whilst flat out.
23-01-2007, 09:02 PM
#18
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Originally Posted by yrkesman
Okay, I have now ordered 5mm longer rods and custom made CP pistons to suit them with 8:1 compression ratio. I hopefully get them in next few feeks so I can get back to my engine build.
Does anyone on here have experiences from using longer rods (let's say those 5-8mm longer versions)? How does it affect performance? Does the powerband go further up, any gues how much? Does it give more power all over the powerband? Just interested in these since I have read somewhere that it would make these things, but I have no idea how it works in reality.
Does anyone on here have experiences from using longer rods (let's say those 5-8mm longer versions)? How does it affect performance? Does the powerband go further up, any gues how much? Does it give more power all over the powerband? Just interested in these since I have read somewhere that it would make these things, but I have no idea how it works in reality.
Mark
23-01-2007, 09:06 PM
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carwise has got a bottom end on ebay now with pistons to suit longer rods.......
http://cgi.ebay.co.uk/ws/eBayISAPI.d...6372&rd=1&rd=1
http://cgi.ebay.co.uk/ws/eBayISAPI.d...6372&rd=1&rd=1
13-09-2007, 11:49 AM
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I finally had time to go to the rollers yesterday. I'm well pleased with the results. Even tough we could have made some more adjustments, but I tought it would not be necesary. I think we could have used more ignition from 6000rpm upwards and the fueling was bit rich, something like AFR11,0. 2deg advacing the ignition gave about 5kW more power at ~6000rpm. The boost is peaking 1.7bar and then slowly drops to 1.5bar at rev limiter. I'll need to do some minor modifications to it so it holds the boost better.
Exhaust temperatures were measured ~2cm from the head at the exhaust manifold, they showed no more than 740-760deg in each 4 runners. I think that they could have been more, so the fueling was maybe too rich/safe. Inlet temperature showed 30deg before the pull and 55after the pull. Newer seen more than 40-45deg on the road although.
Here's the engine spec if someone is interested:
standard 4wd cams (timed inlet 1mm open TDC and exhaust 0.8mm),
ported head with race valve seats,
5mm longer conrods with cp-pistons from TG-racing sweden,
comp ratio around standard 8:1,
3" mongoose exhaust with 3" race catalysator,
rs500 size intercooler,
4wd inlet plenum with modified elbow
Finnish aftermarket ecu, Tatech
Exhaust temperatures were measured ~2cm from the head at the exhaust manifold, they showed no more than 740-760deg in each 4 runners. I think that they could have been more, so the fueling was maybe too rich/safe. Inlet temperature showed 30deg before the pull and 55after the pull. Newer seen more than 40-45deg on the road although.
Here's the engine spec if someone is interested:
standard 4wd cams (timed inlet 1mm open TDC and exhaust 0.8mm),
ported head with race valve seats,
5mm longer conrods with cp-pistons from TG-racing sweden,
comp ratio around standard 8:1,
3" mongoose exhaust with 3" race catalysator,
rs500 size intercooler,
4wd inlet plenum with modified elbow
Finnish aftermarket ecu, Tatech
13-09-2007, 01:34 PM
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Originally Posted by Mike Rainbird
Congrats 
. Is 450bhp what you were hoping for? 
. Is 450bhp what you were hoping for? Here's the old graph for comparison. Basically same engine, but just tweaked a bit.
13-09-2007, 01:43 PM
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Originally Posted by Stavros
What turbo you running? (or did i not spot that bit)
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