|
|
|
|||||||
|
#1
09-30-2002, 09:30 PM
|
||||
|
||||
Attention all Engine Builders...check this out!
Just when I thought I had it all figured out I see this info on a Federal-mogul site. It relates to piston ring end gaps. They say to gap the top ring .016 - .018 for moderate performance, .018 - .020 for drag racing and .020 - .022 for street nitrous applications. Then the second ring is .020 - .022 for moderate performance, .022 - .024 for drag racing and .024 - .026 for street nitrous. Note the larger gap on the second ring. See web site, http://www.federal-mogul.com/speedpr...speed_pro.html
Now I'm totally confused. What to do now? Everything has changed. Auuggh! 
|
|
#2
10-01-2002, 05:55 AM
|
||||
|
||||
This is an interesting page! The reason Speed-Pro recommends this is:
"Notice: Most of the second ring gap recommendations are larger than the top rings. Recent testing has proven that a larger second gap increases the top rings ability to seal combustion. This larger escape path prevents inter-ring pressure from building up and lifting the top ring off the piston allowing combustion to get by. Many engine builders have reported lower blow-by and horsepower gains at the upper RPM ranges with wider second gaps." Most of my older engine books call for the top and 2nd compression rings to have the same gap, so this is a change from common practice. I think Speed-Pro's reasoning is sound, in the old days, they probably didn't even know about things like "inter-ring pressure" so they probably saw no reason to change the gap sizes. Definetly interesting, thanks for the li
|
|
#3
10-01-2002, 09:53 PM
|
||||
|
||||
|
So I am just about to re-ring my 340 with the Speed pro plasma-moly .035" file fit rings. Do I gap them as in the Web site and make the secong ring gap larger than the top or do I do it the conventional way? Who has had experience in this and what do you think I should do. I will hold off installing them till I get a few replies. It is very interesting isn't it.
|
|
#4
10-01-2002, 09:59 PM
|
|||
|
|||
|
Well, I can tell you this. One of the tricks the stock eliminator guys use is to put a smaller ring into the second groove so it is basically just there because the rules say it has to be there. It serves no function.
|
|
#5
10-01-2002, 11:04 PM
|
|||
|
|||
|
Yes, for racing engines that will reduce friction a noticeable amount. But those guys also rebuild regularly. This is not a trick for the street.
Mr. Mopar, I'm not sure you'll find many people who have tried this technique yet, since it is the opposite of what we've been doing for so many years. But unless I've got a good reason for doing differently, I have always given a lot of weight to what the manufacturer recommends.
|
|
#6
10-02-2002, 04:03 AM
|
|||
|
|||
|
This has been around quite for awhile now. I remember reading long time ago when talking about zero gap style rings that some builders had actually seen some gains by opening the second ring gap. The difference is not that big, and when I'm filing rings I usually end up that much bigger anyway
 This differs from one piston to another, some pistons have an expansion groove between the top and second ring groove which purpose is the same as opening up the second ring gap.
|
|
#7
10-02-2002, 09:56 AM
|
||||
|
||||
|
Well, taking a quick look in my 1970 Motors manual shows all v8s are to have a ring gap on the compression rings of .013.
The exceptions are the slant six with a compression ring gap of .010 and the 64 10.5 to 1 426 having .023. That is probably the Max Wedge. The way I see it, is if you're going to be driving the car on the street and want to get a lot of miles out of it, gap the rings according to factory specifications. If engine life isn't as critical and you're going to be doing a lot of racing, give the other specs a try.
|
|
#8
10-02-2002, 06:46 PM
|
||||
|
||||
|
Too much infoo
Mr Mope. As you can see, one can easily get caught up in the numbers thing. I've seen guys drag out a project simply because they're worried about the numbers.
There is reams of info on just any subject in the auto experience. My lowly suggestion would be to go with the manufactures (rings and piston)suggested tolerances. I think that will do you just fine.
|
|
#10
10-05-2002, 12:22 PM
|
||||
|
||||
Quote:
|
|
#11
10-05-2002, 06:17 PM
|
|||
|
|||
|
KB site URL
|
|
#12
10-05-2002, 06:46 PM
|
||||
|
||||
 Not to add fuel to the fire; I have been concidering using the Total Seal Gapless top ring in a 340 rebuild .I have to contact the manufacturer monday,as the pistons I was concidering using are Ross forged with 1/16, 1/16, 3/16 ring grooves and the set they list for the 340 (Total Seal) is for 5/64, 5/64, 3/16 .Total Seal also has some interresting ideas,on the top gapless rings and the second ring gapless. Just a few more thoughts. 
|
|
#13
10-05-2002, 11:59 PM
|
||||
|
||||
|
Got the Speed Pro Plasma-Moly rings and inside were the ring end gap recommendations. To my surprise the end gaps for a street machine were, top ring .016-.018 and second ring, .010-.012. Just the same as in the Mopar manual. Wonder why they haven't updated to the larger second ring end gap as discussed on their website. I went with the specs as outlined above. Should work just fine.
|
|
#14
10-06-2002, 11:54 AM
|
||||
|
||||
|
Jimm II: the 1/16 1/16 set up is the Chebby configuration the other of course being the Mopar.
To my knowledge there is no difference or advantage to either configuration, the Chebby set up offers more choices of size and material. I use the 1/16th size in my motor and it seems to be just fine. Mr. Mopar:....yup just follow the manufacturers intructions and you'll be fine....are we ready to select a cam for that motor yet?
|
|
#15
10-06-2002, 11:17 PM
|
||||
|
||||
|
Well, cuda, she's all back together and I kept the Comp Cams XE268H in it. I put on a re-manufactured Holley 750 vacuum secondary carb, they were on sale here in Canada for $300.00 and thats about all the budget would allow for this year. Same for the cam. It took right off, I set the timing and idle mixture and idle speed and run it at 2500 rpm for about 15 minutes then idled it down and re-checked timing, etc. The idle mixture is much more sensitive with the Holley than with the TQ. I could turn the screws quite a bit with the TQ without any real change. The Holley seems more responsive. It is very cold here today and it was the last race day....rained out! It has been snowing here the last 2 mornings and I'm afraid the Dart will go into hibernation until next year. I won't take it out of the garage unless we get a heat wave. Damn Alberta. Well at least I know it runs, just how well is to be determined at a later date. Rear seal is giving me a little grief, seems to seep a bit. Couldn't ask for everything, I guess. When its time, we will have to power tune that Holley eh? By the way, what cam did you have in mind? Christmas is coming up you know......
|
|
#16
10-07-2002, 12:29 AM
|
||||
|
||||
|
A Holllllley!...jeeze and after all I did for you....LOL
You'll be fine with that holley on there for now, when you get urge to go faster you let me know and we'll get a 650 Speed Demon dog sledded in there. Call Jim Doyle at Racer Brown and see what cam he recommends, I always leave it up to Jim and he's never let me down. You never did let me know what the deal was on the heads?....did that shop find something wrong? Congrats on what sounds like a successful rebuild. Good Job!
|
|
#17
10-07-2002, 10:03 PM
|
||||
|
||||
|
Ya, I know, sorry about the Holley but thats all I could afford right now. Don't worry, I change things around a lot so hang in there. I thought I let you know about the heads but here it is: They flowed one chamber on each head for a comparison and the one 2.02 intake flowed around 211 cfm@.450. It leveled off after that and gained no more. The 1.60 exhaust flowed 160 cfm@.500 and also leveled off. The other head 2.20 intake flowed 202 cfm@.500 and leveled off. The 1.60 exhaust flowed 155cfm@.500 and also leveled off. This was at 28 inHG. So there is some inconsistancies in flow from head to head and the best flow was achieved between .400 and .500 lift. The valves were not sunk in too bad and they said they would pass. The guides were a little loose but running them like they are would also be alright. So short of spending around $1000.00 per head for an expert porting job, (ya, I know....thats what they quoted me!), I put them back on and let er' rip. They also thought that I could have a little stiffer spring but I installed the exact ones that MOPAR recommended good for up to .500 lift. I still have a rich idle condition until it is really warmed up even with the manual choke 750 Holley with the choke wide open.....mmmmm gonna have to teach me sumpthin' there. I guess I could have gotten the E-brock heads but my kid is in College and I must be careful... hence the re-man Holley, sorry again! I think it needs a good run out on the highway to seat the rings and blow out the assembly crap and then we will see what happens. Looks like tommorrow and the next day are the best weather, then it is snow in the forecast again. Here goes nothin"
|
|
#18
10-08-2002, 12:54 AM
|
||||
|
||||
|
Just try bumping the initial timing up a few degrees...you'll hear it pick up.
Just watch your max timing doesn't exceed about 36* Don't worry about the Holley thing..hell some of my best friends still have Holley's on their cars and their real good friends..they always head down to the Motorhome after they loose to cheer me on....LOL.. ..and, hell my wife's name is Holley so they can't be all that bad....LOL
|
|
#19
10-08-2002, 01:36 AM
|
|||
|
|||
|
You can't be serious about the snow man! We are just looking at indian summer up here. You should be good for a few cruises till Halloween!
I'd say I'll be jet boating on the river on rememberance day right after the ceremonies.
|
|
#20
10-09-2002, 12:20 AM
|
||||
|
||||
|
I know its depressing, Brian but just watch the news. They say a high temp of 6*C for the weekend with ocassional flurries. I am closer to Edmonton so there is a big difference from me to you.
Thanks cuda, I'll bump the timing and give that a try. Also I guess I should check the power valve and see where my in gear vacuum is and see which power valve they stuck in there. May help a bit too, eh?
|
|
#21
10-09-2002, 03:18 AM
|
||||
|
||||
|
What? no snow tires Eh?
...about 70 something here today....I was mounting some dock bumpers and sweating my fool head off drilling that concrete.... We'll be out testing "atoetly's" Dart this weekend, forecast is 71 and mostly sunny......  we're down from 10.45 to 10.38 and there's more yet. Definatley check the power valve and also be sure the max timning doesn't exceed 36*. It projects like yours that make me wish I was retired and could afford to hop on a plane and tune that baby up for you.
|
|
#22
10-09-2002, 08:44 PM
|
||||
|
||||
|
I just found these at Canadian Tire, the perfect answer to off season launches. It's a little known product in the Mickey Thompson catalogue. They're expensive, but what price blowing away your buddies 4x4 in January?
|
|
#23
10-09-2002, 09:21 PM
|
|||
|
|||
|
Perfect AJ.....Just dont get Canadian Tire plugs or any other tune up parts from this goof ball outfit
.....Oh yeah....Im in hibernation....Yankees are out
|
|
#24
10-09-2002, 10:05 PM
|
||||
|
||||
|
I bought a u joint from Canadian Tire once. I didn't last 3 launches. Paid less at a UAP store for a Borg Warner that lasted a long time. Pays your money and you takes your chances.....
|
|
#26
10-10-2002, 09:04 AM
|
|||
|
|||
|
Hi Don....Naw, just got back from up country counting sockeye etc....(work for Fisheries)....No steelies here yet, Lots of coho,chinook and doggies.....and people fishin for them that cant tell steelhead from a black crappie
|
|
#27
10-10-2002, 09:32 AM
|
||||
|
||||
|
You work for the dept. of Fishery's and you show up at the track and don't bring us a Salmon!.....jeeze what a guy.....
I heard Creeptian or whatever wants another 1 Million Pakistani immigrants to come to Canada....what's he charging them $20.00 a head for his own pocket?...maybe this is just a rumour...???? I heard a rumor that the Division 6 Regional Finals will be in Mission next Sept., you better plan you vacation time now...."I'll be bach!"
|
|
#28
10-10-2002, 08:41 PM
|
|||
|
|||
|
Hey Don, ya gotta remember that if we get a million of them 750,000 of them are gonna sneak across the border and inhabit some place called Beaverton, Oregon
 ...I will keep an eye on Missions calender...If Im in town ill be there...no woman this time...and if I cant get fresh salmon there will be lots of smoked stuff!
|
|
#29
10-10-2002, 08:51 PM
|
|||
|
|||
|
Mr Mopar, what town do you live in? I live in Whitecourt, I am always looking to buy/sell/trade A-body parts.
|
|
#30
10-10-2002, 09:29 PM
|
||||
|
||||
|
I live in a tiny little one horse town called Daysland. Nothing really exciting happens there. Ya know, go to work, go home, work on the Mopar.....get frustrated........post on this board looking for answers. You know the drill. Kinda weedin out the parts but I have a Mopar 280 cam, 850 TQ, 800 TQ, 14" electric fan and some other stuff. I would have to look around the garage to see.
|
 |
| Thread Tools | |
| Display Modes | |
|
|
Similar Threads
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| For all of you engine builders... | Fury361 | Performance Talk | 6 | 04-03-2004 04:03 AM |
| engine builders? | NavyNorm | Drag Racing Forum | 40 | 06-24-2003 09:29 PM |
| Engine builders | 1970dart | Performance Talk | 6 | 04-13-2003 11:07 AM |
| engine builders can you take a look at this? | keng | Performance Talk | 4 | 07-27-2002 12:03 PM |
| Engine Builders Help | SS/AA Hemi Fan | Drag Racing Forum | 3 | 01-14-2002 07:27 PM |
Linear Mode
