Moparchat - Home of MOPAR enthusiasts worldwide!



Go Back   Moparchat - Home of MOPAR enthusiasts worldwide! > Technical Forums > Performance Talk

Click here to search for Mopar cars and parts for sale.


Reply
 
Thread Tools Display Modes
  #1  
Old 09-08-2005, 03:03 PM
ramcharger_440 ramcharger_440 is offline
Inactive User
 
Join Date: Jan 2003
Location: Chelsea, Ok
Posts: 115
Default What type of rings?

I need to know which type of rings would be best on the engine described below. It's usage will be 95% street with a couple of trips yearly to the "fun drags". Maximum rpm will likely be 6000 but it may be pushed a litttle higher to 6400 if the rest of the combo will take it.

318 block bored to 3.95 with 3.58" stroke crank (351 cubic inches). Cast pistons on reconditioned stock rods. Don't know if you need more info but here it is. Magnum heads with .035 piston to head clearance, mildly ported. Holley 650 mechanical secondaries on a Strip Dominator intake. Comp Cams XE274H camshaft (.521/.524 lift with 274/276 degrees duration and 230/236 duration @ .050) 1 5/8" headers with 2 1/2" exhaust with NO back pressure to speak of (full exhaust with no mufflers). 904 transmission with 2800 stall converter and shift kit. 3.91 gears in a 2800 lb Dart.

We will be building another just like it but will have Stealth dual plane intake with 600 cfm vacuum secondary carb, Comp XE268H cam (.509/.512 lift, 268/280 duration 224/230 @ .050) stock converter with 3.55 gears. Dart will weigh 3050. This car will have free flowing mufflers but haven't decided on brand.

I don't want the expense of gapless rings but don't know if it would be worth it to get file fit. Also like to know if Moly rings or cast would be better and would appreciate a brand recommendation. This is being built on a budget but am willing to spend more if it is necessary.
Reply With Quote
  #2  
Old 09-08-2005, 03:19 PM
perfmachst's Avatar
perfmachst perfmachst is offline
Inactive User
 
Join Date: Jun 2003
Location: yakima, wa.
Posts: 452
Default

hello, go with a moly top ring. have the bores finished in a plateua finish. with cast pistons, the ring combo will be 5/64 style. hastings, speed pro, perfect cirlce have good quality rings. use the ductile top ring. try for the lowest tension oil ring. stay above 14# on oil ring.as far as file gap, it's a personal preference. just food for thought, gapless if you want to spend more money.
Reply With Quote
  #3  
Old 09-08-2005, 04:06 PM
B1owner B1owner is offline
Inactive User
 
Join Date: May 2004
Location: Ford City Pa
Age: 50
Posts: 212
Default Go mid tension or high tension

Low tension oil rings suck on a street motor. Take my word for it unless you want a mosquito fogger engine like my last 340. I know some manufacturers use them in production engines, but if you put them in your small block, you'll regret it. Mopar action adressed this a few issues back in their "race Tech" section. And Ill tell you from experience that they are right when they said to leave them in strip only engines. The low tensions are only worth 10 or so h.p. anyway, maybe not even that when you consider oil isnt very high octane.
Reply With Quote
  #4  
Old 09-08-2005, 08:21 PM
mrbill426's Avatar
mrbill426 mrbill426 is offline
Inactive User
 
Join Date: May 2004
Location: Port Orchard, WA
Age: 69
Posts: 116
Question

On this topic, is it really worth the substantial added cost to buy the file-fit (.005" oversized) rings over the regular +.020", +.030", +.040", etc rings, from say Speed Pro?
Reply With Quote
  #5  
Old 09-08-2005, 10:45 PM
dave571's Avatar
dave571 dave571 is offline
Inactive User
 
Join Date: Feb 2001
Location: carstairs,alberta,canada
Posts: 2,809
Default

I'm going to say go with a set of regular cast iron rings.

They seat fast, and last long.

I don't think files fits are worth the time, but that's my own opinion.
Reply With Quote
  #6  
Old 09-08-2005, 11:41 PM
sanborn sanborn is offline
Inactive User
 
Join Date: May 1999
Location: shelbyville,tn,USA
Posts: 2,880
Default

I think the answer depends on how precise you want your engine to be.

With todays cast pistons(varing as much as they do) I think I would use "file to fit" rings. .001" variation in bore yields .003" variation in ring gap. Too much ring gap allows combustion chamber pressure a place to escape into the oil pan.

I believe the "Total Seal" ring is the best to use, less leak down, etc. But, Total Seal rings require a "mirror" finish on the bores, it's best to use deck plates when honing and high temps allow the rings to loose their tension easily.

"Let your pocketbook and how precise you want the engine be your guide"
Reply With Quote
  #7  
Old 09-09-2005, 01:10 PM
perfmachst's Avatar
perfmachst perfmachst is offline
Inactive User
 
Join Date: Jun 2003
Location: yakima, wa.
Posts: 452
Default

hello, do not use cast rings!!! cast rings require a rougher bore finish. under wide open throttle, raw fuel washes the bores down, the rings require oil to seal to walls. if there isn't enough oil, you loose ring seal. which is lost power. a moly ring will seat instantly, will retain oil under wide open throttle.
as for a lower tension oil ring for the street, they work!!! just don't go below 14 # tension. also use a plateua wall finish. just food for thought.
Reply With Quote
  #8  
Old 09-09-2005, 10:42 PM
dave571's Avatar
dave571 dave571 is offline
Inactive User
 
Join Date: Feb 2001
Location: carstairs,alberta,canada
Posts: 2,809
Default

Quote:
Originally Posted by perfmachst
hello, do not use cast rings!!! cast rings require a rougher bore finish.
That is your opinion, that you are entitled to sir.

My opinion, that I am entilted to, is that in the real world cast rings seat quick , seal well, and last about 100000 miles.

I've built customer motors with cast rings, as well as my own. They perform and last well.

A topic like this will have as may answers as threads like "which cam" "which plugs" and "which tires"
Reply With Quote
  #9  
Old 09-10-2005, 01:07 AM
perfmachst's Avatar
perfmachst perfmachst is offline
Inactive User
 
Join Date: Jun 2003
Location: yakima, wa.
Posts: 452
Default

hello, if "cast rings " are so good?? why doesn't the good engine builders use them in stock, s/s , comp, pro stock?? they use a moly top ring for a very good reason, it seals, make s lots more power, period!!!
Reply With Quote
  #10  
Old 09-10-2005, 11:19 AM
mrbill426's Avatar
mrbill426 mrbill426 is offline
Inactive User
 
Join Date: May 2004
Location: Port Orchard, WA
Age: 69
Posts: 116
Default

Thanks for your input, guys, I appreciate it
Reply With Quote
  #11  
Old 09-10-2005, 08:10 PM
dave571's Avatar
dave571 dave571 is offline
Inactive User
 
Join Date: Feb 2001
Location: carstairs,alberta,canada
Posts: 2,809
Default

Quote:
Originally Posted by perfmachst
hello, if "cast rings " are so good?? why doesn't the good engine builders use them in stock, s/s , comp, pro stock?? they use a moly top ring for a very good reason, it seals, make s lots more power, period!!!
I'm always open to new suggestions.

Got any dyno results that show a comparison of hp with different types of rings, in the same combo?

What do you call "lots more power"?

A full point in compression on most combo's makes a 3 to 4 % difference in engine performance. What type of gains will be seen over cast with these moly rings?
Reply With Quote
  #12  
Old 09-11-2005, 01:27 PM
perfmachst's Avatar
perfmachst perfmachst is offline
Inactive User
 
Join Date: Jun 2003
Location: yakima, wa.
Posts: 452
Default

hello, case in point.circle track motor done with cast rings, would only pull 6800 rpm down back stretch. car ran in the middle of the pack most of season. pulled motor, rehoned finer stone, plateaud finish, installed moly rings. car runs in the top 4 ,runs over 7200 down back stretch. the other shop, who set it up, told him molys were no good, cast only, less work honing a block with cast rings. the driver wanted to know what I done to his motor, had a lot more power. he was very happy with the results. a gain of 400 rpm is a bunch! I do bracket and stock elim motors. haven't seen any cast rings in stock elim motors, all moly tops. like I stated, raw fuel washes down cylinder bore= loss of ring seal= loss of power. molys will withstand that and they will seal! just food for thought! lower ring tensions are also a power maker.
Reply With Quote
  #13  
Old 09-11-2005, 11:35 PM
dave571's Avatar
dave571 dave571 is offline
Inactive User
 
Join Date: Feb 2001
Location: carstairs,alberta,canada
Posts: 2,809
Default

hello

Good example. It would seem that the rings worked better for him.

But a circle track motor spends more time at high rpm, then a drag motor. A drag motor only see's peak rpm for a very short period of time. The same can be said for a street motor, even if driven hard.


The motor in question, you tore it down, and reassembled it?
Was it set up properly to begin with? Cam dialed, etc?
Was it assembled exactly the same, with no changes other than a set of moly rings, and hone?
No other changes to the car, fuel system, etc?
Reply With Quote
  #14  
Old 09-12-2005, 01:14 AM
perfmachst's Avatar
perfmachst perfmachst is offline
Inactive User
 
Join Date: Jun 2003
Location: yakima, wa.
Posts: 452
Default

hello, just a hone and moly rings, yes the motor was done right, I don't build junk!!!! as for a drag motor and street motor, you will get better ring seal with a moly ring, period. circle track motors, drag motors ,street motors all work with varying rpm scales. the motor doesn't know where it's at. all it knows, it revs up, comes down. end of story! maybe you should tell the pro stock racers about how great cast rings are! they use only moly rings!! food for thought,
Reply With Quote
  #15  
Old 09-13-2005, 01:44 AM
dave571's Avatar
dave571 dave571 is offline
Inactive User
 
Join Date: Feb 2001
Location: carstairs,alberta,canada
Posts: 2,809
BS!

Quote:
Originally Posted by perfmachst
hello, just a hone and moly rings, yes the motor was done right, I don't build junk!!!! as for a drag motor and street motor, you will get better ring seal with a moly ring, period. circle track motors, drag motors ,street motors all work with varying rpm scales. the motor doesn't know where it's at. all it knows, it revs up, comes down. end of story! maybe you should tell the pro stock racers about how great cast rings are! they use only moly rings!! food for thought,
I understood from your earlier post that someone else built the motor first, and that's why you had to work on it. Now you say it was built right, because you don't build junk. So which is it?

In any case, I still don't see the dyno results backing up what you have said. Just a story about a re-ring job that went well, with no real info about what was done to the motor when it was built in the first place. Followed by the statement that mol;y rings seal better "period", and that pro stock guys use them so they must be the best. Really scientific arguements.

You can pass on my opinion on rings, to whoever you want.

My opinion is that cast rings seat quickly and last well. This makes them a smart pick for the average street strip motor. Millions (yes millions... ) of production, HP, and aftermarket built engines have proven that.
Moly rings may very well seal better. I have not said at any time that they didn't or couldn't.
BUT... to say that a motor won't make good power using cast rings is nothing more than the normal BS that get's thrown up on message boards, and printed in magazine articles. PERIOD.
Reply With Quote
  #16  
Old 09-13-2005, 04:00 AM
perfmachst's Avatar
perfmachst perfmachst is offline
Inactive User
 
Join Date: Jun 2003
Location: yakima, wa.
Posts: 452
Default

hello, you sir are very wrong, and uneducated about rings and bore finishes.a cast ring will not seal as good as a moly ring under wide open throttle. it is not BS!! you do your thing. I know how rings work and what it takes to make power. must be shady under the tree there.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
are ring rings, or do they need to play nice with the piston brand/type? ShineRunner Performance Talk 2 05-23-2011 02:16 PM
What center section do you prefer the 489 cone type or the 742 clutch type? duetz Performance Talk 6 10-12-2004 03:00 AM
Delayed Sealing piston Rings(Rings haven't seated yet?) Cliff Foster Performance Talk 17 03-20-2003 02:14 PM
File to fit rings or regular rings? shannon Performance Talk 6 04-22-2001 12:33 AM
A RACERBACK TYPE WING HARD TYPE BEDCOVER?? RAMDAVE Ram Truck Chat 4 09-08-2000 03:19 AM




All times are GMT -4. The time now is 03:02 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
. . . . .