DCR. What to aim for?
Discussion
I think I got 28 thou in the top with the piston pushed to one side.
After talks with Roland at ACR he has offered to build the motor free of labour charge for me. Then the engine will be run up and tuned on his dyno. It also looks like I will be swapping over to an Omex 710. The MS2 has served me well the last few years but I want the best reliability and performance I can afford at this stage.
After talks with Roland at ACR he has offered to build the motor free of labour charge for me. Then the engine will be run up and tuned on his dyno. It also looks like I will be swapping over to an Omex 710. The MS2 has served me well the last few years but I want the best reliability and performance I can afford at this stage.
You don't measure the crown to deck clearance with the piston pushed to one side. You take the average of the lowest and highest readings as the piston rocks or use two dial gauges and set the piston crown level so both gauges read the same.
I thought you said it was 7.5 thou down? Now you say 28 thou. A bit of a bloody difference eh?
I thought you said it was 7.5 thou down? Now you say 28 thou. A bit of a bloody difference eh?
We were talking about the clearance at the top of the piston to the bore. I saw 28 thou and 5 thou at the skirt.
Deck height does average 7.5 thou as Roland designed but there is still the issue with a slight tilt along the pin line on the nearside pistons. I can't figure it out so it's going back for a proper inspection.
Deck height does average 7.5 thou as Roland designed but there is still the issue with a slight tilt along the pin line on the nearside pistons. I can't figure it out so it's going back for a proper inspection.
DangerousDerek said:
We were talking about the clearance at the top of the piston to the bore. I saw 28 thou and 5 thou at the skirt.
Are you talking about piston crown to top of bore or piston land to side of bore? You don't measure the piston land to side of bore with the piston in the engine. You measure the top land diameter with a micrometer or vernier.Pumaracing said:
Are you talking about piston crown to top of bore or piston land to side of bore? You don't measure the piston land to side of bore with the piston in the engine. You measure the top land diameter with a micrometer or vernier.
Bore to bore. I know it was not measured properly. I was just commenting a crude dimension check I made to show the piston is probably specced to the figures you quoted in the previous post. I think it was 95.3. Anyway all will be sorted soon I am sure when it's back in the hands of a professional and out of my clumsy mitts.
DangerousDerek said:
Bore to bore. I know it was not measured properly. I was just commenting a crude dimension check I made to show the piston is probably specced to the figures you quoted in the previous post. I think it was 95.3.
Anyway all will be sorted soon I am sure when it's back in the hands of a professional and out of my clumsy mitts.
If you could get the loan of a computer connected to the internet for a bit you could go onto something called Ebay that we have nowadays and buy a digital electronic 6" vernier for a tenner which would save you an inordinate amount of buggering about with feeler gauges.Anyway all will be sorted soon I am sure when it's back in the hands of a professional and out of my clumsy mitts.
http://www.ebay.co.uk/itm/6-150mm-Digital-LCD-Vern...
Don't buy the cheap five quid ones from China that only measure to 0.1mm You want 0.01mm resolution ideally. I paid 80 quid for my Mitutoyo back in the early 90s but they're pennies now.
Pumaracing said:
If you could get the loan of a computer connected to the internet for a bit you could go onto something called Ebay that we have nowadays and buy a digital electronic 6" vernier for a tenner which would save you an inordinate amount of buggering about with feeler gauges.
http://www.ebay.co.uk/itm/6-150mm-Digital-LCD-Vern...
Don't buy the cheap five quid ones from China that only measure to 0.1mm You want 0.01mm resolution ideally. I paid 80 quid for my Mitutoyo back in the early 90s but they're pennies now.
Maybe I do deserve the attitude.http://www.ebay.co.uk/itm/6-150mm-Digital-LCD-Vern...
Don't buy the cheap five quid ones from China that only measure to 0.1mm You want 0.01mm resolution ideally. I paid 80 quid for my Mitutoyo back in the early 90s but they're pennies now.
I have a vernier but it's knacked. Promise i will replace forthwith.
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