Original Posted By: Isablcorky(at)aol.com
Can anyone tell me how tight a newly rebuilt "A" engine should be? Without thehead installed it's all I can do to pull the prop around and with the head mountedand the resulting compression, it's going to be impossible. Admittedly, I don't have a full load of oil in it but it doesn't seem likely thatit will free up that much when I top it off. Tomorrow is my engine guy's dayoff and I know this will keep me awake until I find someonewho has experienced the same thing.I could probably find someone with a chassis or a stationary engine set-up thatI could bolt mine into and get it going with a flywheel and starter but I reallydon't want to take ithe engine off the plane AGAIN. John G., you've had recent experience with two "A"s in the last year, what didyou find? Easy enough to turn over or very difficult? Lou L., whathave you found to be the case with yours or are you up to that point yet?Thanks allLarry________________________________________________________________________________
Pietenpol-List: "A" engine
Re: Pietenpol-List: "A" engine
Original Posted By: Isablcorky(at)aol.com
Subject: Re: Pietenpol-List: "A" engineYou can tighten those connecting rod caps too tight without the proper shims and clearances on a T model and there isn't a heck of a lot of difference from an A.Corky in old Ford country________________________________________________________________________________
Subject: Re: Pietenpol-List: "A" engineYou can tighten those connecting rod caps too tight without the proper shims and clearances on a T model and there isn't a heck of a lot of difference from an A.Corky in old Ford country________________________________________________________________________________
Re: Pietenpol-List: "A" engine
Original Posted By: "John McNarry"
Subject: Re: Pietenpol-List: "A" engine pietenpol-list-digest(at)matronics.comIn a message dated 4/3/01 7:42:10 PM Pacific Daylight Time, lnawms(at)msn.com writes:> Can anyone tell me how tight a newly rebuilt "A" engine should be? Withou> tthe head installed it's all I can do to pull the prop around and with t> he headmounted and the resulting compression, it's going to be impossibl> e. > > Admittedly, I don't have a full load of oil in it but it doesn't seem lik> elythat it will free up that much when I top it off. Tomorrow is my engi> ne guy'sday off and I know this will keep me awake until I find someone> who has experienced the same thing.> > I could probably find someone with a chassis or a stationary engine set-u> pthat I could bolt mine into and get it going with a flywheel and starte> r butI really don't want to take ithe engine off the plane AGAIN. > > John G., you've had recent experience with two "A"s in the last year, wha> tdid you find? Easy enough to turn over or very difficult? Lou L., what> have you found to be the case with yours or are you up to that point yet?> > Thanks all> > Larry> > > Larry,That sounds a little tight. My engine now has 95 hours on it, and it now feels pretty good cold, but is tight warm. The engine for the second airplane (the Bryant /Gantzer aircamper) is also tight. I am assuming (bad word) that your engine is correctly built to the nominal specs and clearances throughout. Howard Henderson (an older piet builder and long time operator) told me not to set the engines up very tight. I think he was right, but every body does anyway. I have to run now, but will continue later and I'm sure Chuck will later today also. Doug Bryant ________________________________________________________________________________
Subject: Re: Pietenpol-List: "A" engine pietenpol-list-digest(at)matronics.comIn a message dated 4/3/01 7:42:10 PM Pacific Daylight Time, lnawms(at)msn.com writes:> Can anyone tell me how tight a newly rebuilt "A" engine should be? Withou> tthe head installed it's all I can do to pull the prop around and with t> he headmounted and the resulting compression, it's going to be impossibl> e. > > Admittedly, I don't have a full load of oil in it but it doesn't seem lik> elythat it will free up that much when I top it off. Tomorrow is my engi> ne guy'sday off and I know this will keep me awake until I find someone> who has experienced the same thing.> > I could probably find someone with a chassis or a stationary engine set-u> pthat I could bolt mine into and get it going with a flywheel and starte> r butI really don't want to take ithe engine off the plane AGAIN. > > John G., you've had recent experience with two "A"s in the last year, wha> tdid you find? Easy enough to turn over or very difficult? Lou L., what> have you found to be the case with yours or are you up to that point yet?> > Thanks all> > Larry> > > Larry,That sounds a little tight. My engine now has 95 hours on it, and it now feels pretty good cold, but is tight warm. The engine for the second airplane (the Bryant /Gantzer aircamper) is also tight. I am assuming (bad word) that your engine is correctly built to the nominal specs and clearances throughout. Howard Henderson (an older piet builder and long time operator) told me not to set the engines up very tight. I think he was right, but every body does anyway. I have to run now, but will continue later and I'm sure Chuck will later today also. Doug Bryant ________________________________________________________________________________
Re: Pietenpol-List: "A" engine
Original Posted By: Larry Williams
Larry Your A engine clearances are fairly tight just like a modern engine.Minimum clearance on an A rod is 0.001". The rings are likely going to betight for a while until the walls and rings seat in. Turn the engine to TDCand rock the prop back and forth. Then try it ninety degrees from TDC.At TDC the pistons, all four, are at the ends of the stroke and don't movemuch. When positioned at ninety the pistons are travelling fast and thetight rings if that's what it is will be more noticeable. If it feels freeat TDC the rods and crank are probably okay. I ran my AA truck engine from new with a fresh rebore pistons and crank.It was tight enough it didn't want to start on the electric starter but wentright off with the hand crank. Its feel changed with in the first hour ofrunning.The airframe and prop with the tail tied down should give you as good abreak in place as any, short of a dyno. Once you get a fire lit in it willloosen up if the clearances are right. Watch the temp and don't be afraid towork it. Too many of us still believe in gentle break ins. It is better toput a variable load on it to flex the rings and seat them. A break in shouldgo something like this.-First start. run at idle a minute or so-Open up to about a 1000 run for a few minutes.-Idle down and shut off.-Check and repair any leaks and make any needed timing/ mixture adjustments.-Restart and run at 1000 until temp starts to come up-idle down and accelerate to about 1500 smoothly several times.-run at steady speeds for no longer than a couple of minutes at a time.-when temp reaches normal, idle down for about a minute and shut off.-retorque head bolts. check coolant, oil, timing etc. mixture and carb ifneed be.-When it cools down check how tight it feels.-Smile and restart!-Run at increasing speeds but not at any steady speed for more than a fewminutes.-accelerate to higher speeds fairly briskly, puts a good gas load on therings to seat them.-If by now your coolant temp is stable try steady prolonged full throttle.Keep an eye on coolant temp.By now you should have about an hours running.This kind of break in for a water cooled engine can ready an engine for fullload in about an hour..A long as the cooling system can handle the heat load run it full out for awhile and each time you let it cool down and restart you should notice itturns easier. An oil change after the first hour on a non filtered enginelike the A is a really good idea to carry out the fine particles.I wish I could have the load the prop puts on the engine in a road vehiclebreak in.Don't idle too long and don't be afraid to work it.The rings are the only item that should need break in.John McPS. don't use an oil pressure gauge on an A. It will just scare you! Aglass flow tube would make more sense.The hotter an A gets the lower the oil pressure as the oil viscosity changeswith temp.Remember it is a gravity and splash fed oiling system not full pressure likeour modern engines. The pump just fills the valve chamber and the dippertray.----- Original Message -----
Larry Your A engine clearances are fairly tight just like a modern engine.Minimum clearance on an A rod is 0.001". The rings are likely going to betight for a while until the walls and rings seat in. Turn the engine to TDCand rock the prop back and forth. Then try it ninety degrees from TDC.At TDC the pistons, all four, are at the ends of the stroke and don't movemuch. When positioned at ninety the pistons are travelling fast and thetight rings if that's what it is will be more noticeable. If it feels freeat TDC the rods and crank are probably okay. I ran my AA truck engine from new with a fresh rebore pistons and crank.It was tight enough it didn't want to start on the electric starter but wentright off with the hand crank. Its feel changed with in the first hour ofrunning.The airframe and prop with the tail tied down should give you as good abreak in place as any, short of a dyno. Once you get a fire lit in it willloosen up if the clearances are right. Watch the temp and don't be afraid towork it. Too many of us still believe in gentle break ins. It is better toput a variable load on it to flex the rings and seat them. A break in shouldgo something like this.-First start. run at idle a minute or so-Open up to about a 1000 run for a few minutes.-Idle down and shut off.-Check and repair any leaks and make any needed timing/ mixture adjustments.-Restart and run at 1000 until temp starts to come up-idle down and accelerate to about 1500 smoothly several times.-run at steady speeds for no longer than a couple of minutes at a time.-when temp reaches normal, idle down for about a minute and shut off.-retorque head bolts. check coolant, oil, timing etc. mixture and carb ifneed be.-When it cools down check how tight it feels.-Smile and restart!-Run at increasing speeds but not at any steady speed for more than a fewminutes.-accelerate to higher speeds fairly briskly, puts a good gas load on therings to seat them.-If by now your coolant temp is stable try steady prolonged full throttle.Keep an eye on coolant temp.By now you should have about an hours running.This kind of break in for a water cooled engine can ready an engine for fullload in about an hour..A long as the cooling system can handle the heat load run it full out for awhile and each time you let it cool down and restart you should notice itturns easier. An oil change after the first hour on a non filtered enginelike the A is a really good idea to carry out the fine particles.I wish I could have the load the prop puts on the engine in a road vehiclebreak in.Don't idle too long and don't be afraid to work it.The rings are the only item that should need break in.John McPS. don't use an oil pressure gauge on an A. It will just scare you! Aglass flow tube would make more sense.The hotter an A gets the lower the oil pressure as the oil viscosity changeswith temp.Remember it is a gravity and splash fed oiling system not full pressure likeour modern engines. The pump just fills the valve chamber and the dippertray.----- Original Message -----
Pietenpol-List: "A" engine
Original Posted By: Dave and Connie
Re: Pietenpol-List: "A" engine
Original Posted By: Larry Williams
Hi Larry:Today is the "A" day; I fired mine up for the first time this morning, (ithad been run in for a couple of hours by the guy that rebuilt it but thatwas with the conventional ignition system). I'm using the WICO Model Xmagneto which mounts on top and is driven by the distributor shaft.Anyway, I got a couple of pops and then a roar. Its running rough and themixture is way too rich, but it is running.As to your question, sounds like your crank journals and/or the rods are abit snug. I'm using a flywheel and starter while its in the test stand andthe starter turns it over OK. To move it by hand I can turn the flywheelbut its tough. I used a couple if 1/4" bolts on opposite sides of theflywheeland used a 1x2 as a lever to move it for timing.Meant to answer your last sooner, but I'm glad you got the S O S magazineOK.Stop by again when you get down this way again.Regards,Lou----- Original Message -----
Hi Larry:Today is the "A" day; I fired mine up for the first time this morning, (ithad been run in for a couple of hours by the guy that rebuilt it but thatwas with the conventional ignition system). I'm using the WICO Model Xmagneto which mounts on top and is driven by the distributor shaft.Anyway, I got a couple of pops and then a roar. Its running rough and themixture is way too rich, but it is running.As to your question, sounds like your crank journals and/or the rods are abit snug. I'm using a flywheel and starter while its in the test stand andthe starter turns it over OK. To move it by hand I can turn the flywheelbut its tough. I used a couple if 1/4" bolts on opposite sides of theflywheeland used a 1x2 as a lever to move it for timing.Meant to answer your last sooner, but I'm glad you got the S O S magazineOK.Stop by again when you get down this way again.Regards,Lou----- Original Message -----