Well, that was an crazy couple of weeks...
Lets start with the high point, we made it
and one of it with it's 70's coupe brethren
So yes was a great weekend, not without issue, but more on that later.
The rebuild took rather longer than hoped (what a surprise) with the exhaust taking about 5 days in total!. It drove under it's own steam for the first time with the new engine at 3:30am on the Friday morning. 4 hrs later it made it to the MOT garage and stalled on the way in, then was tight to turn over....
2hrs later it turned over ok, ran and passed it's MOT - woop!
Then drove home ok but clearly in need of a lot of fettling. Played about a bit, got it running much better and then loaded up to head to Shelsley. There was a bit of a light knock, but too late now, I was going whether it was going to die or not!
Role on Saturday, and things started well. Handicap was 41.65s based on last years time with the Zetec - thing was this was a wet time, so not really representative! First practice run, taking it very very gently, was a 42s, and things felt ok.
2nd practice, tried to take it easy again and got a 40.5s, woops 1s under target time in practice! Role on target time being dropped to 39s - a very fair time for the car to be honest so couldn't complain. Car ran ok, but going a bit faster highlighted how far from a good setup the carbs were running.
Post lunch and it was competitive run time. But the weather had other ideas, and it was now a bit damp. Over lunch I'd changed emulsion tubes and it was a bit better at the top end of the rev range, though still not right, and the 7 year old tyres were not confidence inspiring! Ended at a 41s, following a very messy entry into the esses and finding out the fun way that the new engine has a lot more torque and a boat ancquor at the front mean it likes to wag it's tail rather a lot now! Amazingly it was always planted with the zetec, so clearly a lot of retuning needed to get the chassis to suit the new engine.
Run two, dry at the bottom of the hill, but with black clouds rolling in and spits of rain at the bottom, hmmmmm
Up through crossing and it's going fairly well, but on the entrance to the esses it starts to rain, heavy, and the second half of the esses is done rather sideways! End of the run, 40.34 - so well off target time, but given how messy the run was I'll take it. Pull over at the top and the engine dies - this doesn't look good.
Back in the paddock it's clear that it's not running on one bank correctly, and is breathing fairly heavy. At this point I'm pretty worn out so call it a day - will try fix it in the morning
Sunday arrives and I set to work rebuilding the carb (for the 3rd time this week!) Give everything a good clean out and try again - well it's running on both banks, but it's got one hell of an air leak. Carb back off, rebuild intake manifold, and success. It's running better than yesterday, so I'll take that as a win. By this time first practice for my group is nearly over so I rush down the pits and make it just in time.
Again not trying, as not sure it's going to make it up the hill, but it seems ok - 40.12. That'll do.
At this point I decided to not do anything other than cross every digit and keep going. Though I'll just try get the top end running right - so sling in some smaller air correction jets.
Practice two, steady but trying a bit, and quicker again. 39.56s - target time is pretty in reach then and the car is still going ok and running way better at high revs
In the timed runs I gave it a bit more, actually reving it out a bit (still not right!) and get rewarded with a 38.08 on the final run - 0.92s under target and good enough for 2nd place on handicap! Awesome! and only 0.05s off winning the round.
So great weekend, and so glad the car held together and didn't drive that bad. Get the engine running right, sort the chassis out to suit the new weight up front and get some decent tyres on, and I'd say that the car has to be capable of a 36s, maybe even get into the 35's if I can learn to drive it!
But something about the way the car was running just didn't seem right still. Back in the workshop the next day I ran a compression test and my heart dropped, 5 good cylinders, one with half the compression of the rest - damn.
Head off and the cause became obvious - a piston that'd got very very hot. Bore scored to heck and piston is scrap with rings seized in position and a semi seized pin - thankfully had converted these to fully floating so the rod to pin was still moving ok and rod appears to be ok by some miracle. This explains the breathing and I guess the light knock was piston slap.
So now I have an engine in bits again and parts on the way from the US - feels very familiar. Plan is to get the damaged bore repaired (fit a liner) pop in a new piston, and try again.
Why it failed I don't know, but given the failure I suspect it either ran very very lean due to a carb issue (though doesn't explain why the others cylinders were ok) or it got too hot on that first run to the MOT (it was the middle cylinder so likely to be hottest). Either way, hopefully it'll repair ok and I'll get back out later in the year. Sadly the car won't be making RRG this year though - c'est la vie
Lets start with the high point, we made it
https://www.instagram.com/p/BW3KqO4jpPI
and one of it with it's 70's coupe brethren
https://www.instagram.com/p/BW3dM-rn_IR
So yes was a great weekend, not without issue, but more on that later.
The rebuild took rather longer than hoped (what a surprise) with the exhaust taking about 5 days in total!. It drove under it's own steam for the first time with the new engine at 3:30am on the Friday morning. 4 hrs later it made it to the MOT garage and stalled on the way in, then was tight to turn over....
2hrs later it turned over ok, ran and passed it's MOT - woop!
Then drove home ok but clearly in need of a lot of fettling. Played about a bit, got it running much better and then loaded up to head to Shelsley. There was a bit of a light knock, but too late now, I was going whether it was going to die or not!
Role on Saturday, and things started well. Handicap was 41.65s based on last years time with the Zetec - thing was this was a wet time, so not really representative! First practice run, taking it very very gently, was a 42s, and things felt ok.
2nd practice, tried to take it easy again and got a 40.5s, woops 1s under target time in practice! Role on target time being dropped to 39s - a very fair time for the car to be honest so couldn't complain. Car ran ok, but going a bit faster highlighted how far from a good setup the carbs were running.
Post lunch and it was competitive run time. But the weather had other ideas, and it was now a bit damp. Over lunch I'd changed emulsion tubes and it was a bit better at the top end of the rev range, though still not right, and the 7 year old tyres were not confidence inspiring! Ended at a 41s, following a very messy entry into the esses and finding out the fun way that the new engine has a lot more torque and a boat ancquor at the front mean it likes to wag it's tail rather a lot now! Amazingly it was always planted with the zetec, so clearly a lot of retuning needed to get the chassis to suit the new engine.
Run two, dry at the bottom of the hill, but with black clouds rolling in and spits of rain at the bottom, hmmmmm
Up through crossing and it's going fairly well, but on the entrance to the esses it starts to rain, heavy, and the second half of the esses is done rather sideways! End of the run, 40.34 - so well off target time, but given how messy the run was I'll take it. Pull over at the top and the engine dies - this doesn't look good.
Back in the paddock it's clear that it's not running on one bank correctly, and is breathing fairly heavy. At this point I'm pretty worn out so call it a day - will try fix it in the morning
Sunday arrives and I set to work rebuilding the carb (for the 3rd time this week!) Give everything a good clean out and try again - well it's running on both banks, but it's got one hell of an air leak. Carb back off, rebuild intake manifold, and success. It's running better than yesterday, so I'll take that as a win. By this time first practice for my group is nearly over so I rush down the pits and make it just in time.
Again not trying, as not sure it's going to make it up the hill, but it seems ok - 40.12. That'll do.
At this point I decided to not do anything other than cross every digit and keep going. Though I'll just try get the top end running right - so sling in some smaller air correction jets.
Practice two, steady but trying a bit, and quicker again. 39.56s - target time is pretty in reach then and the car is still going ok and running way better at high revs
In the timed runs I gave it a bit more, actually reving it out a bit (still not right!) and get rewarded with a 38.08 on the final run - 0.92s under target and good enough for 2nd place on handicap! Awesome! and only 0.05s off winning the round.
So great weekend, and so glad the car held together and didn't drive that bad. Get the engine running right, sort the chassis out to suit the new weight up front and get some decent tyres on, and I'd say that the car has to be capable of a 36s, maybe even get into the 35's if I can learn to drive it!
But something about the way the car was running just didn't seem right still. Back in the workshop the next day I ran a compression test and my heart dropped, 5 good cylinders, one with half the compression of the rest - damn.
Head off and the cause became obvious - a piston that'd got very very hot. Bore scored to heck and piston is scrap with rings seized in position and a semi seized pin - thankfully had converted these to fully floating so the rod to pin was still moving ok and rod appears to be ok by some miracle. This explains the breathing and I guess the light knock was piston slap.
So now I have an engine in bits again and parts on the way from the US - feels very familiar. Plan is to get the damaged bore repaired (fit a liner) pop in a new piston, and try again.
Why it failed I don't know, but given the failure I suspect it either ran very very lean due to a carb issue (though doesn't explain why the others cylinders were ok) or it got too hot on that first run to the MOT (it was the middle cylinder so likely to be hottest). Either way, hopefully it'll repair ok and I'll get back out later in the year. Sadly the car won't be making RRG this year though - c'est la vie
