Home build 700hp Hawkeye
#31
#39
What did it make in the end?
#40
Scooby Regular
iTrader: (4)
We stopped play at 630/600 at 2.1bar, didnt see any need to turn the boost up any further as thats more than enough for now. We will push things a bit further after a few months of seat time
#41
I had some base mapping done a few weeks ago so yesterdays session was to turn the power up. Everything went to plan without any issues so was quick and pain free.
We stopped play at 630/600 at 2.1bar, didnt see any need to turn the boost up any further as thats more than enough for now. We will push things a bit further after a few months of seat time
We stopped play at 630/600 at 2.1bar, didnt see any need to turn the boost up any further as thats more than enough for now. We will push things a bit further after a few months of seat time
Have you got a build thread Dubzy?
#45
Long story short, I ran it in on the map that was on the car before i bought it as i essentially only rebuilt the engine I didn't change anything as such. Technically it could have been run full chat on that map.
However after lots of head scratching it turns out the valves were very slightly hitting the pistons when on full advance which when running in an engine isn't very often. So despite the later remap by a different mapper the damage had already been done and the valve fatigue had started already. It wasnt until abut 5000kms later that it eventually let go.
I did a write up on it somewhere where I took a **** load of pictures when I was trying to find the issue. I eventually did by reassembling the engine with some plasticine ontop of the pistons and setting the cam advance to where the original mapper had set it. You could see exactly where the valves were hitting the pistons. The cut outs on the Cosworth pistons didn't exactly help matters either as they were too small. The Wiseco ones in now are much much better in that respect.
I've roughly 8,000 miles on this engine since i rebuilt it all good so far, touch wood.
However after lots of head scratching it turns out the valves were very slightly hitting the pistons when on full advance which when running in an engine isn't very often. So despite the later remap by a different mapper the damage had already been done and the valve fatigue had started already. It wasnt until abut 5000kms later that it eventually let go.
I did a write up on it somewhere where I took a **** load of pictures when I was trying to find the issue. I eventually did by reassembling the engine with some plasticine ontop of the pistons and setting the cam advance to where the original mapper had set it. You could see exactly where the valves were hitting the pistons. The cut outs on the Cosworth pistons didn't exactly help matters either as they were too small. The Wiseco ones in now are much much better in that respect.
I've roughly 8,000 miles on this engine since i rebuilt it all good so far, touch wood.
#48
Scooby Regular
iTrader: (5)
Long story short, I ran it in on the map that was on the car before i bought it as i essentially only rebuilt the engine I didn't change anything as such. Technically it could have been run full chat on that map.
However after lots of head scratching it turns out the valves were very slightly hitting the pistons when on full advance which when running in an engine isn't very often. So despite the later remap by a different mapper the damage had already been done and the valve fatigue had started already. It wasnt until abut 5000kms later that it eventually let go.
I did a write up on it somewhere where I took a **** load of pictures when I was trying to find the issue. I eventually did by reassembling the engine with some plasticine ontop of the pistons and setting the cam advance to where the original mapper had set it. You could see exactly where the valves were hitting the pistons. The cut outs on the Cosworth pistons didn't exactly help matters either as they were too small. The Wiseco ones in now are much much better in that respect.
I've roughly 8,000 miles on this engine since i rebuilt it all good so far, touch wood.
However after lots of head scratching it turns out the valves were very slightly hitting the pistons when on full advance which when running in an engine isn't very often. So despite the later remap by a different mapper the damage had already been done and the valve fatigue had started already. It wasnt until abut 5000kms later that it eventually let go.
I did a write up on it somewhere where I took a **** load of pictures when I was trying to find the issue. I eventually did by reassembling the engine with some plasticine ontop of the pistons and setting the cam advance to where the original mapper had set it. You could see exactly where the valves were hitting the pistons. The cut outs on the Cosworth pistons didn't exactly help matters either as they were too small. The Wiseco ones in now are much much better in that respect.
I've roughly 8,000 miles on this engine since i rebuilt it all good so far, touch wood.
What a disaster, and one waiting to happen too. It sounds like an endorsement for pistons other than Cosworth, surprising that they are unaware of the problem. I guess you would now test valve/piston clearance on full advance as a matter of course when building an engine.
#49
Im being a bit hard on Cosworth there as there isn't an issue if the cam advance isn't advanced too far but the guys who built and tuned the car were just **** I unearthed all sorts of crap from them when I tore the engine down when I first bought the car. (i bought it with an engine failure). The Wisecos though have a far bigger ptv clearance. But you're right it'll be a dry build with plasticine ontop of the pistons from now on!
Last edited by dazdavies; 23 November 2016 at 10:55 AM.
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