Ring Tension Again!

trmnatr · Post by **trmnatr** » Sun Jul 27, 2008 3:51 pm

Strange Magic wrote:
I'd say 550-575 HP, the car weighs 2800 and goes 10.0's at 132. It's a 427 standard bore.
I highly doubt you have anything that would be around 13.0 compression let alone 14 to 1 compression. Your car weight, hp and et/mph results show otherwise.

Your piston doesn't look that off track other than maybe the incorrect timing. You should be up around 39 to 41 degrees. You will have to play with it to determin which would better suit the engines needs. The amount of oil in the pan will have an impact on ring seal as well.

First of all, let me say, come run at the track he runs at which is my local track also. That track can be .2-.4 slower than some other tracks any more - They dont do a great job, they do a fair job

They allowed one guy to oil the track down 5 times and the track was so unsafe they pulled the bracket racing event down to 1/8

After the first oil down any car should have to go through tech to make sure its not leaking before they make another pass

Ron Gusack · Post by **Ron Gusack** » Sun Jul 27, 2008 4:58 pm

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PostPosted: Sun Jul 27, 2008 2:14 pm Post subject: Reply with quote
Quote:
Dome 49.456

Based upon numerous BBC builds, I would have to wager that the dome when cc'd is not 49 cc's, although I could be wrong. I have seen many of times piston manufactures advertise domes and they were not what they advertise and I have also seen 49 to 52 cc domes that need a lot of material removal to fit without crashing in a 105 cc chamber. If it truely is 14.1 compression, than you are truely smoking this engine with cam 2 purple. It will detonate severely on it. I personally wouldn't recommend cam 2 purple in anything above 11.5-11.7. You need to be on sunoco Blue supreme.

At 427 cubic inches, and at the weight as described with 14.1 compression, this ride should be considerably faster in mph and considerably quicker in et.

Quote:
There's 7 quarts of oil total. I run an Oberg with about 3 feet of braided line to and from the filter, 6 feet total.

Drop out 1 quart of oil, set the timing at 41 and put some sunoco blue in it. You will need timing to get that flame over the dome.

The only way I could be off in the measuring is if the burette that I'm using is off. I measured the dome volume twice. The other factor is that there was grease above the top ring, but below the piston deck, that could change the number a little. I'll have to check this burette to see how accurate it is. We're talking static compression, the dynamic is the real telling factor and I haven't figured that. I'm not thrilled with the performance, which is why I'm asking for advice. The dome is very tight in the chamber, you can see the clean areas on the walls of the dome and the chamber. I had to index the plugs to keep them from closing. There's no signs of detonation or pre-ignition. There are signs of either oil or over rich or both. Based on the pattern on the piston, don't you think the flame is getting across the dome? I've considered taking a quart of oil out, but it scares me to do that.

Alan Roehrich · Post by **Alan Roehrich** » Sun Jul 27, 2008 7:42 pm

I'd agree, it is next to impossible to get a 49cc dome into MOST 105cc chambers. Especially if you have around 0.042" total deck clearance, and around 0.006" or so bore clearance. It can be done, but it generally means that you or some one has done some serious measuring and massaging.

IF you have an honest 14:1, and are running 110 octane fuel, then you are detonating, even if you DON'T have an oil control problem. Unless you have 280 degrees duration on a 108 or tighter lobe separation angle, and are running less than 36 degrees timing.

If it is indeed detonating, you'll NEVER keep the rings sealed. You could put rebuilder oil rings in it and it would oil soon enough.

Now you need to take a NEW compression ring and put it in the top and second grooves, and see how thick a feeler gauge you can get in with it, DO NOT try to cram it in. I'd be surprised if the grooves, or at least the top one, hasn't opened up. If it has, it won't seal up.

If I can run a 427 with the oil ring expander 0.040" smaller than the bore size is supposed to require, with no vacuum pump, no dry sump, and no crank case evac, then you shouldn't have any trouble doing it. My 427 has so little ring tension that the fully assembled engine, without the valves adjusted, will rotate with only 10 foot pounds of torque, even including the break away torque to start it turning. My 427 makes over 580HP, with a flat tappet .520 lift cam, and it goes through the lights at 8000 RPM on a good pass in good air.

MaxFlow · Post by **MaxFlow** » Sun Jul 27, 2008 8:25 pm

Alan brought up a point that gets overlooked so many times. Detonation and ring seal don't mix. 107-112 track gas and 14.1 don't mix especially with big domes.

That flamefront is atrocious. Between oiling, detonation, carburetion, ect...that engine is down big time. It needs to come completely apart anyway for rings and while its down message those domes up, put some decent gas in there......git er tuned up.

Ron Gusack · Post by **Ron Gusack** » Sun Jul 27, 2008 10:28 pm

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PostPosted: Sun Jul 27, 2008 6:41 pm Post subject: Reply with quote
I'd agree, it is next to impossible to get a 49cc dome into MOST 105cc chambers. Especially if you have around 0.042" total deck clearance, and around 0.006" or so bore clearance. It can be done, but it generally means that you or some one has done some serious measuring and massaging.

IF you have an honest 14:1, and are running 110 octane fuel, then you are detonating, even if you DON'T have an oil control problem. Unless you have 280 degrees duration on a 108 or tighter lobe separation angle, and are running less than 36 degrees timing.

If it is indeed detonating, you'll NEVER keep the rings sealed. You could put rebuilder oil rings in it and it would oil soon enough.

Now you need to take a NEW compression ring and put it in the top and second grooves, and see how thick a feeler gauge you can get in with it, DO NOT try to cram it in. I'd be surprised if the grooves, or at least the top one, hasn't opened up. If it has, it won't seal up.

If I can run a 427 with the oil ring expander 0.040" smaller than the bore size is supposed to require, with no vacuum pump, no dry sump, and no crank case evac, then you shouldn't have any trouble doing it. My 427 has so little ring tension that the fully assembled engine, without the valves adjusted, will rotate with only 10 foot pounds of torque, even including the break away torque to start it turning. My 427 makes over 580HP, with a flat tappet .520 lift cam, and it goes through the lights at 8000 RPM on a good pass in good air.

Alan, Thank you for contributing, I certainly need the help. I put a new ring in top groove, I can get a .0015 in and .002 won't go. In the second groove .002 will go. I have extra pistons that are brand new and the results are the same. It doesn't seem like the grooves have opened up. This cam is 270/280 with 108 separation and I do run the timing at 36-37. SO, either I'm very lucky or my burette is way off and I really only have 12:1. Until I confirm my measurements, I will hold off on any engine assembly. What rings would you suggest? My rotating assembly is pretty heavy, with old Manley rods and pistons.

MaxFlow
PostPosted: Sun Jul 27, 2008 7:25 pm Post subject:
Alan brought up a point that gets overlooked so many times. Detonation and ring seal don't mix. 107-112 track gas and 14.1 don't mix especially with big domes.

That flamefront is atrocious. Between oiling, detonation, carburetion, ect...that engine is down big time. It needs to come completely apart anyway for rings and while its down message those domes up, put some decent gas in there......git er tuned up.

Thank you for jumping in. I've shown these pistons to many people that are supposed to be in the know and no one has been critical of the way the flame pattern looks. I have always thought it looked bad, both in color and pattern. I hope I can straighten this thing out with everyones help. Tell me what the flame front should look like. I don't really want to have to buy better gas, so my first chore will be to verify my measurements.

Alan Roehrich · Post by **Alan Roehrich** » Mon Jul 28, 2008 7:34 am

Ron, Keith Jones at Total Seal is the guy that does my racing rings. Although I do not use their gapless rings (or anyone else's gapless rings). The Total Seal Gold or AP series rings will be fine, I like to get a Napier cut on the second ring. I always use a Speed Pro SS50U oil ring, I've never had nearly as good results with the Hastings style oil ring. I like 0.001" vertical ring clearance, BUT the ring and the groove have to be near perfect.

It's been posted here before, but I'll say it again. The single biggest problem with ring seal and oil consumption is honing issues. Most common is glazing or burnishing caused by low hone oil flow, too much pressure, or too hard a stone. I finish my cylinders with 400 grit stones and follow with a plateau brush. The key is I FLOOD cylinders with CLEAN hone oil, I use a soft stone, and once I get past 150 grit on the stones, I only take out 0.0005" or less. You can often get by with taking 0.001" with 220 or 280 grit stones, if you're careful, but there is a risk there and mistakes can be made. Once a cylinder is burnished or glazed, you need to take 0.001" at least to get a good finish. I have been successful taking 0.0005" out with 220 and then 280 stones to get the 0.0001", following with about 5-8 strokes with 400 stones with low pressure, and then a plateau brush.

These days, I wash my cylinder walls with one of those alkaline liquid soaps like Purple Power, scrubbing them until there is no residue. Then I wipe them DRY with a lint free rag or cloth wet with WD-40. Final prep on the cylinder is a vigorous rub of Total Seal Qwik Seat. If it turns green, the cylinder is clean, if not, stop and wash it again. I use no oil on the cylinders, I use Total Seal AL-4 on the piston and rings, a drop in each ring groove, then rotate the rings until they are coated and so are the grooves. Then a drop on each skirt, and rub that on, including on the ring surface where it touches the cylinder wall. The result is engines that seal up instantly, and rarely even puff smoke the first time they start new.

Alan Roehrich · Post by **Alan Roehrich** » Mon Jul 28, 2008 8:16 am

The reason you're car is faster with that intake is that your cam is too big. That and I don't know anyone racing a "Demon" carburetor with any real success. I'd step back about 10 degrees in duration, go back to the single plane intake, and get a 950 carburetor based on a 4150 HP style body. Given that you're running a 427 that cam should peak close to 8000 RPM. I'd be looking at a cam between the mid 260's and the low 270's in duration, on about a 108 lobe separation angle, and be leaning towards the small side.

For example, back when I was fooling with Super Gas, I could run easy 9.50's with a 468 with 12.2:1 compression, oval port heads, a Holley Strip Dominator intake, an 850 carburetor, and the cam was a Huggins 266/276/108-.656/.663, and it was a flat tappet. The car weighed 2950 with me in it. The heads were unported, with big valves and a bowl hog only.

What I'm getting at here is you've got WAY too much BIG stuff to have so little power and go that slow. For another example, our Stock Eliminator AA/SA Camaro weighs over 3300#. It has a 427 with 11.7:1 compression, GM 401 aluminum heads, a GM 359 dual plane intake, a Holley 750 vacuum secondary carburetor, and the cam is a flat tappet, 256/266/108, with .520 lift. The engine makes a little over 580HP on the dyno. In good air, the car runs steady mid 9.90's, in decent air mid 10.1's, and in horrible air it runs about 10.30, with it detuned to keep it from spinning.

I'm not trying to beat up on you or pick on you. I'm trying to get you headed in the right direction so you go faster. Your engine should be making at least 650 or more, at around 7700 RPM or so.

Ron Gusack · Post by **Ron Gusack** » Mon Jul 28, 2008 10:08 am

I'm not trying to beat up on you or pick on you. I'm trying to get you headed in the right direction so you go faster. Your engine should be making at least 650 or more, at around 7700 RPM or so.

Alan, No offense taken here. In fact I appreciate the time that you and other good racers/builders are willing to take to help someone as lost as I appear to be. I have known for a long time that the car doesn't perform very well, but I get lots of bad advice to sift through. I just had a cam reground on the advice of a cam expert and he sent me bigger in lift and just a tad shorter in duration.

As for the walls, I'm at the mercy of the machine shop that I take my stuff to. There is a guy close by that has a good rep in stock/super stock that I could try. Do you know Bub Whitaker, in Maryland. I thought the killer motors had smooth as glass walls.

Can I buy just SS50U's somewhere and get just compression rings from Total Seal? Who should I talk to about cams? The first thing I have to know is the real compression. I was skeptical on my first measurement, so I took it apart, re-assembled everything and re-measured......And it came out the same. So I guess me burette is off. I measured the chambers a couple of years ago with a different burette, so maybe there's a slight problem there. I put the piston 1 inch down, measured with a depth micrometer in 2 places. I fill it and subtract that number from a calculated number based on the bore, one inch down. The formula I use is borexborex1x.7854, which gives me cubic inches. Multiply that by 16.387 to get cc's. Does that sound right?

trmnatr · Post by **trmnatr** » Mon Jul 28, 2008 11:12 am

Ron Gusack wrote:
I'm not trying to beat up on you or pick on you. I'm trying to get you headed in the right direction so you go faster. Your engine should be making at least 650 or more, at around 7700 RPM or so.
Alan, No offense taken here. In fact I appreciate the time that you and other good racers/builders are willing to take to help someone as lost as I appear to be. I have known for a long time that the car doesn't perform very well, but I get lots of bad advice to sift through. I just had a cam reground on the advice of a cam expert and he sent me bigger in lift and just a tad shorter in duration.

As for the walls, I'm at the mercy of the machine shop that I take my stuff to. There is a guy close by that has a good rep in stock/super stock that I could try. Do you know Bub Whitaker, in Maryland. I thought the killer motors had smooth as glass walls.

Can I buy just SS50U's somewhere and get just compression rings from Total Seal? Who should I talk to about cams? The first thing I have to know is the real compression. I was skeptical on my first measurement, so I took it apart, re-assembled everything and re-measured......And it came out the same. So I guess me burette is off. I measured the chambers a couple of years ago with a different burette, so maybe there's a slight problem there. I put the piston 1 inch down, measured with a depth micrometer in 2 places. I fill it and subtract that number from a calculated number based on the bore, one inch down. The formula I use is borexborex1x.7854, which gives me cubic inches. Multiply that by 16.387 to get cc's. Does that sound right?

Its easy for someone to say your cam is too big. I have been told that too and went to the suggested cam and slowed down. My old 327 ran a 283/291 @.050 .680/.632 on a 106° lobe center - Look at super stock 327's, they will run 276/284 or 278/284-288 with 1.8/1.6 rockers - It doesnt slow them down

There is nothing wrong with a Demon if properly set up right - I took an AED off and replaced with a Demon set up by me and his car went .3 quicker, yes .3 quicker - thats blows the theory out of the water that the Demon is the problem

The Demon he has may have a little too large of a venturii in my opinion - I would use the 1.400" venturii which is the 750 model

NOTE" The Demon modified by me that went .3 quicker than the AED had a choke tower

Wolfplace · Post by **Wolfplace** » Mon Jul 28, 2008 11:49 am

trmnatr wrote:
Its easy for someone to say your cam is too big. I have been told that too and went to the suggested cam and slowed down. My old 327 ran a 283/291 @.050 .680/.632 on a 106° lobe center - Look at super stock 327's, they will run 276/284 or 278/284-288 with 1.8/1.6 rockers - It doesnt slow them down

There is nothing wrong with a Demon if properly set up right - I took an AED off and replaced with a Demon set up by me and his car went .3 quicker, yes .3 quicker - thats blows the theory out of the water that the Demon is the problem

The Demon he has may have a little too large of a venturii in my opinion - I would use the 1.400" venturii which is the 750 model

NOTE" The Demon modified by me that went .3 quicker than the AED had a choke tower

=
Butch
Was the AED a 2bbl

Seriously,,
If you picked up 3 tenths changing to a Demon all I can say is something was very very wrong with the carb that came off
I don't care what brand of carb you have,,
If it is remotely close to correct you are not going to gain 3 tenths

Ron Gusack · Post by **Ron Gusack** » Mon Jul 28, 2008 2:01 pm

Larry Meaux told me that he has never made more power on the dyno with any Barry Grant/Demon carb. The only reason I got this one was because I got a very good price on it and I wanted to try a 4150.

Metrobilly · Post by **Metrobilly** » Mon Jul 28, 2008 2:52 pm

I have been extremely pleased with the work Bub and Burtonsville Machine have done for me. I've had great results with the cylinder bore finish both in terms of break in and durability. They also have done a fine job of keeping an amateur race engine builder, like myself, out of trouble.

Alan Roehrich · Post by **Alan Roehrich** » Mon Jul 28, 2008 2:53 pm

Ron, Bub Whitaker is sharp, I'd certainly suggest you take your stuff to him if he is close.

A deal on parts is only a deal if it runs good and doesn't break. I've never seen a fast or consistent Demon carburetor. I'd much rather start with a Quick Fuel or a Holley HP.

On the cam, there are a couple of guys here you can talk to, Mike or Harold for example, or you can talk to Tim Cole or Chris Padgitt at Comp.

Yeah, it may be easy for me to SAY your cam is too big. However gaining the experience that allows me to know it is too big was very difficult, and took a few years.

Ron Gusack · Post by **Ron Gusack** » Mon Jul 28, 2008 4:10 pm

On the cam, there are a couple of guys here you can talk to, Mike or Harold for example, or you can talk to Tim Cole or Chris Padgitt at Comp.

What do you think of 725/725 279/287 @.050. Waaaaaay big, right? That's the cam that I got after talking to one of the guys you mentioned.

I'll contact Bub. I used to race with him back in the early 70's. He had a CMP Nova and I had a BMP Chevelle. We used the same machine shop back then and it's the one I still use today.

Strange Magic · Post by **Strange Magic** » Mon Jul 28, 2008 5:38 pm

Butch
Was the AED a 2bbl

Was that two barrell attached to a Biondo or Dedenbear throttle stop?