machine work time
Senior User
Joined: Sep 2000
Posts: 435
Likes: 1
From: Central Oregon
machine work time
William, thanks for asking!
Took Old Yellow for an 80 mile maiden voyage yesterday afternoon, a fair amount of that in the snow! The engine runs smooth, but is still pretty tight. It "feels" like I may have lost a little bit of torque with the lower CR, but I'm not jumping to any conclusions until it gets a few miles on it and I finish tweaking the timing, mixture, etc. I love the feel of a balanced engine after driving so many years with whatever came out of the box! I revved him to a little over 5000 once, "just to get the feel", and he sounds and pulls like he would like to go lots more, in spite of the Edel Performer intake and modest cam. Best part was pulling back into the driveway, and not a sign of extraneous noises or oil or antifreeze drips anywhere! I always hold my breath on the rear main seal and valley seals when I stick one of these old beasties together, and figure for sure that I must have adjusted at least one valve wrong.
Oh, guess I forgot to mention the most important aspect: No sign of ping or detonation whatsoever, but I was only running 11d initial and 35d total timing on 89 octane gas, so I need to jazz that up a little to see what happens. That might show a major benefit on the "torquiness" too, hope so anyway. I ran the various combinations on Perf Trends "Engine Analyzer" software before I decided what to do. According to it, there shouldn't be too much of a difference in performance by dropping the CR, so I'm sure I have some tuning time cut out for me! Just wish it would warm up a little so I could enjoy leaning over the radiator! The way it feels outside today, it may be Spring before I get real enthused about it.
Steve
Took Old Yellow for an 80 mile maiden voyage yesterday afternoon, a fair amount of that in the snow! The engine runs smooth, but is still pretty tight. It "feels" like I may have lost a little bit of torque with the lower CR, but I'm not jumping to any conclusions until it gets a few miles on it and I finish tweaking the timing, mixture, etc. I love the feel of a balanced engine after driving so many years with whatever came out of the box! I revved him to a little over 5000 once, "just to get the feel", and he sounds and pulls like he would like to go lots more, in spite of the Edel Performer intake and modest cam. Best part was pulling back into the driveway, and not a sign of extraneous noises or oil or antifreeze drips anywhere! I always hold my breath on the rear main seal and valley seals when I stick one of these old beasties together, and figure for sure that I must have adjusted at least one valve wrong.
Oh, guess I forgot to mention the most important aspect: No sign of ping or detonation whatsoever, but I was only running 11d initial and 35d total timing on 89 octane gas, so I need to jazz that up a little to see what happens. That might show a major benefit on the "torquiness" too, hope so anyway. I ran the various combinations on Perf Trends "Engine Analyzer" software before I decided what to do. According to it, there shouldn't be too much of a difference in performance by dropping the CR, so I'm sure I have some tuning time cut out for me! Just wish it would warm up a little so I could enjoy leaning over the radiator! The way it feels outside today, it may be Spring before I get real enthused about it.
Steve
Logistics Pro
Joined: Feb 2000
Posts: 3,565
Likes: 9
From: Sun River St. George
machine work time
Steve, The Ross 22 cc pistons seem to be the ticket to reduced compression. Is that a standard part? What is the number? I remember you were considering having your pistons cut by your machine shop. I'd like to copy your work on these pistons. If you don't mind! I will build a 410 (Truck Motor) using components I outlined earlier, I do need help with the CR and piston selection. Thanks!
William in Atlanta
William in Atlanta
Senior User
Joined: Sep 2000
Posts: 435
Likes: 1
From: Central Oregon
machine work time
William,
Boy do I wish that the pistons had been an off-the-shelf item, but alas, they (Ross)had to make them to my specifications. They took nearly a month to get, and cost nearly $750 thru my machinist! I think I would still have liked a chance to try a little higher CR, but based upon my machinist's experience and recommendations, and Ross's collaboration on what was needed for the specific application, the 22cc dish was what I used.
I looked over your "410 formula" earlier, and it is pretty much down the line of what I wound up with, except for your head studs and cam. I also had my block decked to get down to minimal quench as another part of minimizing the detonation potential with the Silvolite pistons. The Hastings site has pretty good technical info on that stuff. Of course, if you get custom pistons with that in mind, you can avoid having to deck, but I did it while I was still trying to make the Silvolites work! I'm confident that your recipe will give you a very servicable if not "hot" engine, and it should last a lot of miles. I wish I could get on with the final tuning on mine to give you a more informed report, but the weather just isn't conducive to outdoors play with an engine right now. But the skiing is fantastic! Guess that gives away where my priorities lie at present?!? But I will try to keep you up to date on how I'm coming along, if your time line has enough slack in it.
Good Luck! Steve
Boy do I wish that the pistons had been an off-the-shelf item, but alas, they (Ross)had to make them to my specifications. They took nearly a month to get, and cost nearly $750 thru my machinist! I think I would still have liked a chance to try a little higher CR, but based upon my machinist's experience and recommendations, and Ross's collaboration on what was needed for the specific application, the 22cc dish was what I used.
I looked over your "410 formula" earlier, and it is pretty much down the line of what I wound up with, except for your head studs and cam. I also had my block decked to get down to minimal quench as another part of minimizing the detonation potential with the Silvolite pistons. The Hastings site has pretty good technical info on that stuff. Of course, if you get custom pistons with that in mind, you can avoid having to deck, but I did it while I was still trying to make the Silvolites work! I'm confident that your recipe will give you a very servicable if not "hot" engine, and it should last a lot of miles. I wish I could get on with the final tuning on mine to give you a more informed report, but the weather just isn't conducive to outdoors play with an engine right now. But the skiing is fantastic! Guess that gives away where my priorities lie at present?!? But I will try to keep you up to date on how I'm coming along, if your time line has enough slack in it.
Good Luck! Steve
Logistics Pro
Joined: Feb 2000
Posts: 3,565
Likes: 9
From: Sun River St. George
machine work time
Steve, Thank You for the info! My time line is long, I do this for fun! About the "deck". Did your pistons wind up .005 down the hole or were they "zero deck"? I'm thinking decking the block may increase the CR? I really appreciate your thoughtful and experienced narration on this 410 business. I and others here can proabibly live with a 10-1 CR on our trucks and run higher octane fuel. Most of my driving is hi-way and no load. But 9-1 CR and 87 octane is my goal. Thanks again for all your help. Please post back.
William in Atlanta
William in Atlanta
Senior User
Joined: Sep 2000
Posts: 435
Likes: 1
From: Central Oregon
machine work time
William,
Yes, my pistons did wind up at .005" down the hole (actually #1 was .007", I figured from a goofy rod resizing!?!). Anyway, your deck clearance will definitely affect the CR more than you might expect, as well as quench which may be even more important, so you want to be sure to take that into account before you start machining away iron. The Silvolites had a compression height of 1.660", thus required the original block decking, while 410 standard pistons and Ross's are at 1.675"(my Ross's are 1.662"), certainly enough to make a significant difference in outcome.
I don't use my truck much in the winter, as both other cars are all-wheel drive and much more stable in the snow due to better weight distribution, so I'm not in a panicky hurry to get it finished. But the first time the sun decides to peek out for a day or two, I will be charging after it to see what I can do to get it dialed in.
Steve
Yes, my pistons did wind up at .005" down the hole (actually #1 was .007", I figured from a goofy rod resizing!?!). Anyway, your deck clearance will definitely affect the CR more than you might expect, as well as quench which may be even more important, so you want to be sure to take that into account before you start machining away iron. The Silvolites had a compression height of 1.660", thus required the original block decking, while 410 standard pistons and Ross's are at 1.675"(my Ross's are 1.662"), certainly enough to make a significant difference in outcome.
I don't use my truck much in the winter, as both other cars are all-wheel drive and much more stable in the snow due to better weight distribution, so I'm not in a panicky hurry to get it finished. But the first time the sun decides to peek out for a day or two, I will be charging after it to see what I can do to get it dialed in.
Steve
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