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cast or moly??
#686584
05/02/10 02:43 PM
05/02/10 02:43 PM
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Joined: Aug 2008
Posts: 1,568
Omaha, Nebraska
Scott Carl
OP
pro stock
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OP
pro stock
Joined: Aug 2008
Posts: 1,568
Omaha, Nebraska
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If I can get away with it, (Yes I will mic the holes) I want to just re-ring my '74 318. It will be strictly a street car with a mild .478(?) cam (sorry, don't have the specs handy but it probably will be one of Comp's kits), duals through magnum exhaust, a Carter 600 cfm AVS over a stock intake, 904 in front of a 8 3/4 rear with (depending on what I can find and afford), 3.31 or 3.55 gears. I'm looking at Mancinni's engine rebuild kits and my question is this: Do I want cast or moly rings? I thought I read one is better than the other depending on if its a re-ring or full re-bore, but can't find a definitive answer. Of course, if the mic says so I will buy pistons too but I'm hoping to get away as cheaply as possible without worrying about having to do it again next year  Also, Mancinni offers two brands of kits; Clevite and Sealed Power. SP is a little higher price. Is it worth the extra couple dollars over the Clevite products? Thanks, Scott 
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Re: cast or moly??
[Re: Scott Carl]
#686585
05/02/10 03:06 PM
05/02/10 03:06 PM
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Joined: Sep 2007
Posts: 14,889
up yours
Supercuda
About to go away
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About to go away
Joined: Sep 2007
Posts: 14,889
up yours
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Moly is best, easiest on the bores. Cast is dirt cheap which is why the OEM's used to use it, but it eats bores.
However, Moly rings take a different hone finish to seat properly. If your 74 318 came with cast rings and you have a lot of miles it would not surprise me one bit that you would need a bore job. My 87 318 had factory moly rings and even at almost 200k miles it didn't need a bore job, regular oil changes too.
As for which brand to buy, both are/were good names, but it would not surprise me one bit if they are the same parts in different bxes anymore. Only a few manufacturers of that stuff anymore.
They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.
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Re: cast or moly??
[Re: Scott Carl]
#686586
05/02/10 03:28 PM
05/02/10 03:28 PM
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Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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When you open it up you will have a dead smooth bore and I'd also say Moly though I understand cast seals a bit better if the bores have a fair amt of taper/out of round. the trick is to be patient and conservative w the ridge reamer and NOT take out all of the ridge because if you do there will be some areas around the circumference where you are past the ridge and into the wall and #1 pull the blade toward you rather than pushing it around the circumference which means you need to change positions many times as you move around the engine. Get the cheapest set of the two you mentioned and break off one of the old rings in two and grind a hook on the end and grind the edge straight across and use it to CAREFULLY clean the carbon from the grooves and .004"/.003" gap per inch of bore on the top/second rings respectively works for me and read "breakin secrets" at www.mototuneusa.com
live every 24 hour block of time like it's your last day on earth
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Re: cast or moly??
[Re: RapidRobert]
#686587
05/02/10 06:08 PM
05/02/10 06:08 PM
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Joined: Aug 2008
Posts: 1,568
Omaha, Nebraska
Scott Carl
OP
pro stock
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OP
pro stock
Joined: Aug 2008
Posts: 1,568
Omaha, Nebraska
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Quote:
When you open it up you will have a dead smooth bore and I'd also say Moly though I understand cast seals a bit better if the bores have a fair amt of taper/out of round.
Thanks guys
Robert, I understand that the bore will be smooth, but can I use new rings as is? Won't I need to hone the cross hatch in them to get them to seat? 
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Re: cast or moly??
[Re: RapidRobert]
#686590
05/02/10 10:34 PM
05/02/10 10:34 PM
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Joined: Aug 2008
Posts: 1,568
Omaha, Nebraska
Scott Carl
OP
pro stock
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OP
pro stock
Joined: Aug 2008
Posts: 1,568
Omaha, Nebraska
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Quote:
Quote:
Robert, I understand that the bore will be smooth, but can I use new rings as is? Won't I need to hone the cross hatch in them to get them to seat?
Cast rings no, moly yes that has worked good in the past for us but they do need to be loaded hard. but there are schools of thought that moly (& cast for sure) needs a dingleberry hone of the proper grit
Thanks again guys.
Robert, I assume by, "need to be loaded hard", you mean broke in hard; Right?
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Re: cast or moly??
[Re: Scott Carl]
#686593
05/02/10 11:13 PM
05/02/10 11:13 PM
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Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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If you're just doing a backyard hone'n're-ring, you want cast rings. They are more forgiving where it's said moly rings require a more perfect bore than cast. I used sealed power cast rings when I did my hone'n're-ring job and it worked out great. However they say the best rings out there for the backyard job are Hastings rings. They're supposed to be a bit softer and conform better to a worn bore. If you're boring out and going with new pistons, then moly for sure. Doing it yourself in your garage, then go for the cast. 
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Re: cast or moly??
[Re: DaytonaTurbo]
#686594
05/03/10 03:46 PM
05/03/10 03:46 PM
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Joined: Jun 2006
Posts: 5,163
CT
GTX MATT
master
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master
Joined: Jun 2006
Posts: 5,163
CT
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I dont want to hijack the thread but Im thinking of doing a back yard rebuild on my 440. Just wondering, how much lost compression can actually be gained back by re-ringing? I know it was somewhat of a regular procedure for engines back in the olden days. You would freshen up an engine after so many miles.
My 440 has about 100000 on it. It is tired and you can feel it. The cranking compression is about 120. It uses alot of oil (about a quart every 500 miles), and the breather leaves alot of oil residue on the valve cover, even with a PCV valve. Assuming the bores are within spec, how much would I gain by re-ringing and lapping in the valves?
Now I need to pin those needles, got to feel that heat
Hear my motor screamin while I'm tearin up the street
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Re: cast or moly??
[Re: GTX MATT]
#686595
05/03/10 04:04 PM
05/03/10 04:04 PM
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Joined: Jan 2003
Posts: 6,531
Jacksonville, FL
Chris2581
master
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master
Joined: Jan 2003
Posts: 6,531
Jacksonville, FL
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I use moly rings in everything.I don't care if it's a John Deere tractor,it gets a moly ring set.Use a dingle ball hone and put it together.
Nautilus Racing-
We use Superformance gaskets and Turbo Action converters/products.
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Re: cast or moly??
[Re: Dodgem]
#686597
05/03/10 06:55 PM
05/03/10 06:55 PM
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Joined: Mar 2003
Posts: 571
Beaverton, OR, USA
Alikazam
super gas
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super gas
Joined: Mar 2003
Posts: 571
Beaverton, OR, USA
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Only the top ring is moly anyway, in a ring set, fyi. The middle ring is cast. That being said, I agree with others go with cast unless bores are really smooth, then dingleberry hone/moly ring set. Good luck  As for the 440 cranking psi, hard to say how much you'd gain, it depends on static and dynamic compression ratio. You'd need to know static CR and cam specs to even get close to being able to estimate what the cranking PSI should be. for instance, my 360 pulled about 210 psi when new with 10.07:1 CR. 222/230 @ .050 cam, 112 lsa, etc.
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Re: cast or moly??
[Re: dOc !]
#686599
05/03/10 10:17 PM
05/03/10 10:17 PM
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Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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Quote:
So WHERE is the best shot on buying a dingleberry?
I've bought them on ebay but I did my last rering with the 3-stone hone. Worked just fine.
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Re: cast or moly??
[Re: Alikazam]
#686601
05/04/10 12:24 AM
05/04/10 12:24 AM
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Joined: Aug 2008
Posts: 1,568
Omaha, Nebraska
Scott Carl
OP
pro stock
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OP
pro stock
Joined: Aug 2008
Posts: 1,568
Omaha, Nebraska
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Quote:
Only the top ring is moly anyway, in a ring set, fyi. The middle ring is cast. That being said, I agree with others go with cast unless bores are really smooth, then dingleberry hone/moly ring set. Good luck
My 318 has just at 100k but based on the few engines I've had apart, which I can count without taking my socks off  , my bores will be shiny smooth. So I could use cast rings by just removing the ridge and putting the rings in and running it??? I just assumed I would have to break the smoothness regardless of the ring choice. Correct me if I'm wrong but I seem to remember the difference in ring choice determined the angle in degrees of the cross hatch pattern. Not whether you had to hone. Am I going too old school then?? This is from Auto Mechanics class circa 1975 
Thanks again
Scott
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Re: cast or moly??
[Re: DaytonaTurbo]
#686604
05/04/10 01:31 PM
05/04/10 01:31 PM
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Joined: Jul 2008
Posts: 30,439
Florida STAYcation
dOc !
The village idiot's idiot
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The village idiot's idiot
Joined: Jul 2008
Posts: 30,439
Florida STAYcation
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Quote:
Quote:
So WHERE is the best shot on buying a dingleberry?
I've bought them on ebay but I did my last rering with the 3-stone hone. Worked just fine.
High-pressure stone-type ? ... or just the lite-spring-pressured one?
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