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My other thread has gone into the archives and I don't know how to find it, so I'll just do this new one. Here are some pictures of the insides of Dan's 455 Olds engine. Now that I look at the scoring on cylinder number 3 it looks like the lines are too straight to be some random broken off carbon. It looks like maybe a broken ring? What do you experts on this stuff think?
Thanks,
Don
And here are some pictures of the valves and chambers on number 1 and 3. The engine has maybe 500 miles on it and looks like it has 200,000 from all the oil getting in.:(
BTW, I found a new bare block locally and we are going to pick it up tomorrow. We just want to start with a clean sheet of paper and build a new engine. I am also going to not use my usual machine shop but will use the guy who did Dan's brake drums and my pulleys recently. He races an 8 second blown S10, so he should know his stuff.
Don
carbon will not do that .steel will..... end gap butting busted rings .looks to have a bad guide in the head or bad valves seal s or both ez to check
Pat, when you say "end gap butting busted rings", do you think one of the rings has busted into several pieces, or what? What would cause that?
Thanks for the reply.
Don
I agree with Pat that looks like metal scraping metal. The burnt oil and carbon build up are really bizarre for only 500 miles too. Don't know what is going on there.
Another two cents?? I'd sure suspect a busted ring or two - but I ain't no eggspurt. :p
I think I'd just rebuild or replace those heads; new seats and guides, seals, the works. :whacked:
Is that a little bit of oil on top of the piston , One way to find out what's wrong is drop the rod and piston out , Something in the ring department has been done wrong , I wonder what the side of the piston looks like !
Who built the engine ?
not enough end gap can make the ring butt and bust .looks like the intakes have had new guides put in at one time looks like 502 guides
Pat, that makes sense about the end gap causing the problem. The engine did get up to 230 a couple of times until the cooling system burped the air out, then it would come down and stay at 190-200. Maybe that didn't help.
Steve, it looked different to me last night when I first saw the scoring, but tonight when I took the pictures the true pattern of the scraping showed up and it was obvious they were very straight and deep, like steel had done it.
Rrumbler, yep, we have a new set of C heads that will get the full treatment. The ones we had are Ga heads and were done by someone else and will become doorstops.
Street T, we are going to start pulling things apart so we can disassemble the engine completely. We built the engine, twice actually. The first time was about 5 years ago and it sat so long before he got the car done that we tore it apart and completely went through it a second time.
On the plus side, we can salvage a lot of the parts to reuse when we get the new block back from the machine shop. The car had 50 psi oil pressure and the cam and lifters broke in very well, no wear at all on them. We will have the pistons cleaned up and at least 7 of them should be reusable, so we will maybe only have to buy one to replace that suspect one.
We will take EXTRA care this time fitting the rings and the rest of the parts to make sure this doesn't happen again. :o While we are talking about rings, what type do you guys like for a street engine.....cast iron, moly, chrome, etc.?
Thanks everyone for the help, I'll post some pictures of what the internals look like when we get it torn down.
Don
This sucks for Dan. It will be interesting to see if a different block and heads makes a difference in the intake manifold fitment.
As for finding your previous post, go to your profile page, in the upper left is a box of links, one of them is for "find all started threads", and there's also "find all posts". This is the stuff that used to be under the "statistics" tab.
i use alot of hasting rings of stock to mild use use there moly top ring rings . for race i use je rings .speed pro hell fire. mahl.total seal tnt. as alot to do with what there going in and how much Nos some rings have a better oil ring expander then others to work with .with stock fitted rings they can be off for gap and can be file fitted i do this all the time its not hard to be off 003 on ring gap for about every 001 of bore. on most every build i like the rings with abit more end gap so they will not butt and i check all ring gaps for every build
Thanks Bob. Roger sent me a PM too, telling me how to find previous posts. Once you guys explained how it was pretty simple.
Pat, thanks for that info on the rings. Is it preferable to buy the ones you have to file to fit over the ones that you don't? I think I will buy a ring filer and do them with that. I saw them using one on one of the car shows on TV and it didn't look super expensive, but it was better than using a hand file.
Today when Dan gets off work we are meeting the guy who is selling the bare 455 block. Sure hope it looks good and if it does I'll drop it off at the machine shop tomorrow.
Don
Hi Don, i hadn't heard of Dans bad luck but just saw this, I'm with Pat as i think the ring gaps were to tight/wrong and as they have expanded they havn't had anywhere to go.
Quote:
Originally Posted by Itoldyouso
KD Tools makes a ring fileing tool part # 870. This is the one that I've used. They can be had for about $70.00 or so. You'll also need to get a ring squareing tool to put rings squaely in bore for accurate measurements. Also if you havn't done this before, I suggest practicing on some used rings before cutting on your new rings.
Steve, he (and I ) are a little bummed about having to pull the body off and build a new motor, but it is what it is.:http://www.clubhotrod.com/shop-talk/48665-what-do-you-engine-guys-see-here-post429146.html#post429146\" rel=\"nofollow\">
Pat, when we get to the point of installing rings I'll be back with more questions for you guys.
Thanks,
Don
Looks to me like one of the ring lips on the piston could have broken off also.
I've been wondering if that is what we are going to find also.
Don
a ring land could of busted . i never look at your piston numbers.. but pistons tops and ring lands do bust out from piston rings with no end gap . hyper pistons will bust the land out as most need more end gap. i got in to checking all my ring gaps many years ago so i knew all the rings were the right size for bore like a 040 over in a 030 ring box :) seen rings mixup missing and chiped and bent in new ring box it happens .i never assume any new parts are right or they fit .some guys think its all new and fresh machined just bolt it up ? i know many storys of stuff not fitting i sure jerry know s some to .. of stuff not fitting or a guy not checking a parts for fit .the one you do not check is the one that bite you in the ass .
Pat, here is what Sealed Power quotes about these pistons:
Forged Piston 0.142 Dish, 4.125 Bore, 4.250 Stroke, 6.735 Rod, 455 Oldsmobile
$53.99Part Number: L2323F
SKU: L2323F
Brand: Sealed Power
Price: $53.99
TRW Power Forged pistons have become the standard by which pistons
are compared. The complete piston manufacturing proceess, from the
raw materials to the finished product is directly handled by TRW.
From OE type replacement to all out racing motors, Power Forged
pistons provide the same dependable performance experienced by
winners of countless races every week! *Compression ratio is
figured with 70.0cc heads.
Forged Piston 0.142 Dish, 4.125 Bore, 4.250 Stroke, 6.735 Rod, 455 Oldsmobile (L2323F) Specifications
Forged Piston 0.142 Dish, 4.125 Bore, 4.250 Stroke, 6.735 Rod, 455 Oldsmobile (L2323F) Specifications
Bore Diameter (in.): 4.125
Compression Ratio: 10.0:1
Dish / Dome Volume (cc): -18
Pin Height (in.): 1.735
Ring Package: 5/64 5/64 3/16
Rod Length (in.): 6.735
Stroke (in.): 4.250
Weight (grams): 672
Wrist Pin Type: Pressed
Don
well don long as you know that new pistons can be smaller then were they should be see it all the time .so lets say he put the piston in at.0025 or less piston to wall if you have a smaller piston by .001 and that piston he fit it to the bore it could be .003 les on end gap . so you could at or less then .014 for end gap thats way to small for a top ring heat makes them grow
I would tear it apart before anything else to see what happened. I've used plasma ceramic rings with good success.
Every set of pistons I ever used when checked would be around +/- .002" varience in diameter. For example a set of 4" pistons lets say +.030 over would actually measure in a set of eight from 4.029" to 4.031". Sometimes the varience in diameter was more. Too much more and we would order other pistons and send back the ones too far out of spec. Basically make up our own set of pistons within .002" tolerance. This is why we used to bore the block to fit the pistons and file fit the rings to get the correct gap.
Heres a chart from Sealed Power / Speed Pro giving reccomended end gaps per application.
RING END GAP RECOMMENDATION GUIDE (FOR 4.000 INCH BORE)
Speed Pro Top Rings
(ductile iron, 4" bore) 4.000" Example Minimum Gap Factor
Moderate Performance .016 - .018 (.004 per inch of bore diameter)
Drag Racing, Oval Track .018 - .020 (.0045 per inch of bore diameter)
Nitrous Oxide - Street .020 - .022 (.005 per inch of bore diameter)
Nitrous Oxide - Drag .028 - .030 (.007 per inch of bore diameter)
Supercharged .024 - .026 (.006 per inch of bore diameter)
Speed Pro 2nd Rings
(cast Iron, 4" bore) 4.000" Example Minimum Gap Factor
Moderate Performance .020 - .022 (.005 per inch of bore diameter)
Drag Racing, Oval Track .022 - .024 (.0055 per inch of bore diameter)
Nitrous Oxide - Street .024 - .026 (.006 per inch of bore diameter)
Nitrous Oxide - Drag .028 - .030 (.007 per inch of bore diameter)
Supercharged .024 - .026 (.006 per inch of bore diameter)
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 ring's 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 ring gaps. Also,
almost every new car made is using this inter-ring pressure reduction method to lower blow-by and emissions and to
increase engine output
If EVERY set of pistons you have used vary that much I got a few tips for you---
Get a better measuring tool-----
Get someone else to measure them---
buy a different brand of pistons---
I doubt that the 4.030 pistons measured anywhere near 4.029-4.031(maybe 4.025---)
Don
If all the oil was coming from the manifold surface there would be a trail around the valve stem/guide area---that looks like the oil came directly out the guide
Before I would go to all the work of a different block, I would see what/how much size it takes to clean up that area----sometimes a little detonation will knock off the ring land of the piston and they scrape like that--you can probably see pass the top edge and get an idea of what happened--rock the piston over a little with a screwdriver blade for a better look
Ooops! I stand corrected. My example was bad. Cylinder bore may have been within that range but forgot about piston to cylinder wall clearance and true diameter of piston.:oQuote:
Originally Posted by jerry clayton
Don i've used one of these Speedway type for years without any problems.
This one works good, i also have the electric version.
Precision Piston Ring Filer - Speedway Motors, America's Oldest Speed Shop
Don I enjoy screwing my own engines together after the parts come back from the machine shop, and even though I trust the machine shop(s) I use I still check everything. It adds at least a couple of hours to the build but that's a lot less than pulling the engine back out and re-doing it. I doesn't happen everytime, but it's not unusual for me to find at least 1 ring in a set that is a little tight.
What is nice about rubbing elbows with guys like some of you who know how to really put an engine together is that shadetree guys like me can learn a lot. I'm probably like most car guys, I just take the parts out of the box and assume they are within specs.........you guys check every piece and make corrections and allowances to make them fit properly. I think that is what happened with this engine, the end gaps were too tight and butted up and caused the rings to fail.
As far as maybe overboring the engine another 20 thousandths, it looks like the scoring might be deeper than that in some spots, but won't know until a machinist looks at the block. If boring it over is possible that would be great, and save us having to use a new block. But it will probably be smart to buy the block we found locally anyway as Olds 455 blocks don't come available very often around here.
Thanks for all the help, we will post what we find when the engine comes apart.
Don
Don
don't bore that hole---take it to someone with a Sunnen CK10 and have them hone it til it cleans up and then measure it--I'd bet a 6 pack of cold ones that .010-.012 will clean it up
even if it does`nt clean up 100 % it will still be ok .. my 351 has a few cylinder scratches and run just fine .. 98% seal is good also
Really? When you run your finger or fingernail across the scoring they seem pretty deep. I have no feel for if that equates to more than 20 thou, but they sure seem deeper than that. But I am just guessing and your suggestions might be correct........I sure hope so, it would save a lot of work (and money).
I'll run that all by the machinist for sure. Thanks Jerry and Hoss.
Don
I would gladly send you a 6 pack of your favorite brew, Jerry, if that is the case. :LOL:
jerry you must remember them old trw s i have had sets of pistons that were.001 smaller in a set.i had one set had to wait for them for two month KBs one was 001.5 . i used it and fitted it to the hole she was going in do it all the time some guy will walk in with blow up pistons and no money and clean the skrits and bore/hone them to each hole...jerry your just use to work with nice pistons .i get lucky some times was week 3 cylinder ford sleeved 3 holes honed it to day for new mahle pistons and sunday a 4.611 bore bbc diamond pistons both sets were good for size :)Quote:
Originally Posted by jerry clayton
I used to use alot of TRW forged pistons for my builds back in the day and what you say here is true. I see that sealed power or federal mougal owns them now. Also it's been near 30 years since I've built engines. Really out of touch with the newer stuff and the apparent improvements in manufacture tollerances of parts and pieces now days.Quote:
Originally Posted by pat mccarthy
well yes and no i had better size on cheap cast pistons . then the race stuff for size to size in a set now they put coating on the skrit and you cant mic it for real size you bore it for the size whey want and hope for the best if i know its going to live a hard life i throw another .0005 or .001 on the bore .
Tonight when he gets home from work Dan and I are going to meet with the guy who has the bare 455 block and if it looks good we are going to buy it "just in case" the old one can't be saved, or at least saved reasonably. They don't show up every day, so we don't want to pass it up and then need it later.
Don
So what is this coating they put on the piston skirt and why? Does it really make a difference in wear? Does it somehow keep the skirt from collapsing? Is this coating optional?
Damn, things have changed alot since I used to do this.:confused::o
that one can be fixed EZ one sleeve put in bored and honed to size + sleeve $100.Quote:
Originally Posted by Itoldyouso