Help me evaluate these photos. Chamber and Piston

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user-9274568

Help me evaluate these photos. Chamber and Piston

Post by user-9274568 »

Here is a link and a photo of my 4 cylinder. It appers to be a fat oily pig! Tell me what you see. Thanks for any ideas and suggestions..

www.speierautosales.com/sb2.htm

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Last edited by user-9274568 on Sat Feb 23, 2008 10:32 am, edited 1 time in total.
Procision-Auto
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Post by Procision-Auto »

Is this a race motor, or street motor?

The reason I ask is due to the gas ports.
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Post by user-9274568 »

By the looks of these nasty photos, I should tell you a street engine. However it made 460@9300 so I better call it a race engine. Something isn't happy..
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Post by Unkl Ian »

How many miles on it ?
Did you do a leak down test ?

Noticeable amount of blow by ?
Oil consumption ?

460 hp 4 cyl.
Turbo or blown ?
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Post by user-9274568 »

12 dyno pulls and two full quarter mile runs.

I did leak it, less than 5%

never seen any blow by on the guage on the dyno.

no turbo or blown, it has a dominator on it.
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Post by Procision-Auto »

Ring gaps ./ ring seal ok?

Are you getting oil past the rings, up through the ports possibly?
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Post by needforspeed66gt »

Total Seal rings?
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Post by user-9274568 »

.020-.023 on gap. JE Pro Series

I have a 57 oil rig in a 4.166 bore. I also think the vacuum pump is jacked up. I showed 12 on the guage, but it could be off.. I need more like a honest 15+
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Re: Help me evaluate these photos. Chamber and Piston

Post by xenginebuilder »

cspeier wrote:Here is a link and a photo of my 4 cylinder. It appers to be a fat oily pig! Tell me what you see. Thanks for any ideas and suggestions..
A couple of observations based on your pictures, I don't know if they pertain to your problem;
Your gas ports show trace burns on the piston surface leading away from each hole, to my mind evidence that the burned material (oil) is coming up from the port. I assume that you are using a vacuum pump, and low tension oil rings, so is it possible that at 9300 rpm you are loosing vacuum and pressurizing the crank case, forcing the oil up past the rings?
At least one intake valve is also very wet around the edges, is there a guide seal issue? If I'm counting coils properly, you're running triple element springs, is there enough room for seals and are you using seals? Sprinklers? Is there oil in the intake port?

Just curious, but do you "clutch" the engine after a run, or does it back down in gear at some rpm for a while?
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Post by user-9274568 »

I do run seals, the pound on Kline type, they were an issue, like they weren't even on the guide..

No oil in the port.

I click it past the finish line.

I think I might have had too much oil in the pan..
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Post by xenginebuilder »

cspeier wrote:I do run seals, the pound on Kline type, they were an issue, like they weren't even on the guide..

No oil in the port.

I click it past the finish line.

I think I might have had too much oil in the pan..
It's late, and I'm thinking off the top of my head-
I guess the question is when did/does it oil? I would think that at WOT if you are still carrying vacuum and don't have blowby, then the implication is that you have good combustion seal. That oil is present in quantity in the combustion chamber at some time or other is clear from the pictures. My thought on the sprinklers is that if there is inadequate drainback capability you can easily fill the head and immerse the valve stems in oil, and with the tight clearance between the inner spring and guide, I know a lot of drag racers don't run the seals at all. High speed and spring immersion can overcome a seal as well. BUT, since you don't have oil in the port, I guess that's not the deal.

If you "had too much oil in the pan", then you are running a wet sump. I suppose that you might have had no issue on the dyno pulls, but under hard acceleration the oil could have climbed up the back of the pan and crank reciprocation could have overcome the ring control, but I would have to say that your problem is not confined to 2 passes at the track.

Going back to the tracks from the gas ports, I don't think you have very good ring seal at anything less that WOT, so you probably are loading up with oil and then burning and blasting it out when you put your foot in it.
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Post by MaxFlow »

xenginebuilder is right on the track marks, she's getting oil from the bottom up someway. My guess is the oil ring is failing someway. From no pan vac/big rpm low tension. Low tension oil rings in my experiences show their dreary heads at high rpm with no vacuum.
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Post by Ed-vancedEngines »

xenginebuilder,
You better change your handle Dude ;) Ain't nothing x about your sharpness and knowledge from where I am sitting.

I was paying so much attention to the appearance of inclomplete combustion and where it was hot at only one spot that I failed to see the oil trails from the gas ports. Good catch, sir.

My sucessful ring package with Normal aspirated higher rpm engines;
Total Seal AP Stainless top ring .043 cut to a radial thickness of .135 using .040 gas ports with no chamfer. 2nd ring Napier .043 radial thickness of .145 gapped at what is recommended by Total Seal, same as with Top ring, as recommended. Oil package is regular or standard tension oil rings every since 1981, no light oil rings for me.

Mix all that well and stir in some Total Seal Qucik-Seat with AP4 ring pre-lube used as recommended. Break in by loading engine either on dyno or in car but first several minutes I let engine run high idle, kill, check everything, I like it all to get cold then. Next ready for the re-torquing if needed. Check it anyway.

Fire it up again, tweek, tune etc, and start loading the engine at upper rpm;s after loading a few times, kill, check everything, adjsut what is needed and next time go for broke. Never let new engine idle if you can keep it from idling. Actually it is harder on a race engine to idle than it is to get down the track.

Chad,
I know you already know stuff I wrote but many look at these threads, that might not know some of it.

I would like to see corrosponding pics of combustion chambers, surely you took some?

What rod and quench are you set up to run with this? I see little evidence if any of a squish effct on those pistons. I flat don't like that burn pattern.

You are making good power already, it can only get better. I try to get a good even burn all the way across with the fire quenching just before the inside edge of piston. With a nitrous engine which I do a lot of now, that burn pattern is not easy if not impossible for me to get, but with all normal aspirated stuff, I can usually achieve it, but with some engines, it takes a few tries of changing things each time it is down.

Ed
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Post by user-9274568 »

Ed follow the link at the top, it has more photos.

5.820 rod
-.010 in the hole
1034 gasket
15.4 compression

It's a single stage pump with a HUGE Charlie's Pan. I did have a major issue with pullover, maybe the rings are gone. Also, I was down on vacuum. I might have an issue with the pump. It had only 12" on the dyno.

Another thing, the guy that did the head just told me the plug isn't far enough in the head and that will clean and help uniform the burn pattern.
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Post by jmarkaudio »

Chad, what plug do you run? There are two plug styles you can run, first is the 3/4" reach gasketed such as the R5671 and there is a .708 reach tapered seat made by Autolite. You might try the opposite of what you run now to see if it goes in a little further. Looks like new rings are in order as well... :cry:
Mark Whitener
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