Thread: Too much crankcase pressure, novice engine builder

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record the timing reading you get and the rpm--check for how far it advances as you add rpm and record-

Most tuning places will be tuning your car for max HP so will want higher octance fuel to run more timing advance------

if you want to tune for street performance and available fuel at your location-tell them that---------and they can work around just drivability at street RPM

Since you had a failure of the chins wall gasket and you used rtv-------maybe you have a oil leak at the corner of the heads/manifold that is running down the front cover and just appears to be leaking there--------

wish you were closer so I could help-------.

NegativeZero, Jerry's comment,

Originally Posted by jerry clayton

Most tuning places will be tuning your car for max HP so will want higher octance fuel to run more timing advance------

made me think that you need to be sure that the tuner you're going to knows how to work with an old school carbureted engine with no computer controls. Most of the hot shot tuners today tune for max HP and Torque like Jerry says, knowing that the computer will then take care of any differences that come up, and even self learn the changes over time. Take them a new Mustang, Camaro or Challenger and they may tune it with BP 106 octane, and then when they fill the tank with 93 octane the ECU will back out a ton of timing, and may increase the signal to the injectors to keep everything good. You need an old school tuner, not a kid who only knows the modern stuff, IMO. Or tell Jerry you'll buy his gas & hamburgers for a trip to Choctaw, OK, and let him have some fun!

I'm with you Rodger, Jerry can fix anything he's got easily!!!! And it would be cheaper than going to a tuner, especially one that doesn't know carbs.

And beware! A trick some dyno tuners use, is he'll hold back on the first few runs so it shows improvement later no mater what (hard to collect big bucks if there's no improvement).

Alright, a lot to catch up on now that the holidays are over

In short:
I believe what happened was I washed out my piston rings from running it too rich. I wasn't aware that this was a possibility and I knew there was a danger in running too lean, so I purposefully was running fairly rich ever since I got it running (about a month ago).

Long story version:
I drove my car to a local tuner. I know people that have used him and I trust his work. We talked for about an hour, I gave him all the details and everything I've done. At this point, my car smokes a lot from the leaking oil as well as the excessive blow by. In his opinion, my ring gaps alone wouldn't cause this issue and after talking more he's confident I washed out my rings from running it too rich. I got my car back to my garage, did another compression test with about 2 weeks and about a hundred miles on the engine since the first test. 2 of the cylinders were sub 80 psi, which told me, yea, I botched the ring break in. So, next week, I'll be putting in some fresh rings.

That being said, I appreciate all the advice here. Also what are y'all's opinions on ring materials and break in procedures.

Originally Posted by rspears

NegativeZero, Jerry's comment, made me think that you need to be sure that the tuner you're going to knows how to work with an old school carbureted engine with no computer controls. Most of the hot shot tuners today tune for max HP and Torque like Jerry says, knowing that the computer will then take care of any differences that come up, and even self learn the changes over time. Take them a new Mustang, Camaro or Challenger and they may tune it with BP 106 octane, and then when they fill the tank with 93 octane the ECU will back out a ton of timing, and may increase the signal to the injectors to keep everything good. You need an old school tuner, not a kid who only knows the modern stuff, IMO. Or tell Jerry you'll buy his gas & hamburgers for a trip to Choctaw, OK, and let him have some fun!

Unfortunately, the only tuner I know of doesn't even do carb tuning. I'd love to meet someone that knows what they're doing with these. The only way I've had to learn is basically from Youtube, and while easily accessible and expansive, it's not the best teacher for things that are often as unique as building an engine from a million different parts. My plan for "tuning" was basically to rent some time on a dyno and make the adjustments myself, timing and AFR and such and just see what makes power.

Originally Posted by NegativeZero

I'm running a 1411 Edelbrock. I have an AFR gauge and it's set to run a little bit rich right now just because I don't completely know what I'm doing when it comes to power tuning and I know it's better to be rich than lean. I currently have it idling around 13.5 AFR and WOT gets to about 12.0 AFR..

JMHO, your AFR numbers above are not rich enough to wash the rings. And, the compression dropping severely is a good indication of there may be more trouble ahead.
Glad you're tearing it down, hope you get it solved.

Originally Posted by 36 sedan

JMHO, your AFR numbers above are not rich enough to wash the rings. And, the compression dropping severely is a good indication of there may be more trouble ahead.
Glad you're tearing it down, hope you get it solved.

Yea once I saw that big a drop in compression, I knew it was time to crack it open. Rings are fairly cheep, so I'm honestly not too bothered by it. Planning on reducing the gap to 24 on the top and 25 on the bottom. I still think that leaves plenty of room for low boost applications and will hopefully reduce blow-by. Also adding a windage tray so hopefully keep crankcase pressure down a little bit more.

Check the bearings as well as I believe they might be just a tad out of spec.

Originally Posted by NegativeZero

Yea once I saw that big a drop in compression, I knew it was time to crack it open. Rings are fairly cheep, so I'm honestly not too bothered by it. Planning on reducing the gap to 24 on the top and 25 on the bottom. I still think that leaves plenty of room for low boost applications and will hopefully reduce blow-by. Also adding a windage tray so hopefully keep crankcase pressure down a little bit more.

JMHO, I really don't think your ring gaps were causing your trouble, unless they were significantly larger than you posted. In my youth (a long, long time ago) I ran some pretty worn out motors, a few had enough blow by to lay out a smoke screen and oil slick out the tail pipes, yet not enough crankcase pressure to blow out gaskets.

When you tear it down look it over closely, I believe there's more to this story than what meets the eye.

Also, I think you are a little confused on what a windage tray does, it does NOT reduce blow by or crankcase pressure, generally they are good at minimizing aeration of the oil at high RPM, which helps with a speedy return of the oil to the sump. There are lots of pro's and con's (and opinions) on windage trays.

I was told when I was young (many years ago) there are two phrases that apply to motor building and troubleshooting;
MOTOR BUILDING - Check, check, check, MAKE MISTAKES less, less, less
TROUBLESHOOTING - Test, test, test, SPEND less, less, less

Originally Posted by NegativeZero

Unfortunately, the only tuner I know of doesn't even do carb tuning. I'd love to meet someone that knows what they're doing with these... My plan for "tuning" was basically to rent some time on a dyno and make the adjustments myself, timing and AFR and such and just see what makes power.

IMO you'll be spending, and wasting a LOT of money with your plan to rent dyno time, and you won't gain anything from it but an empty wallet or big credit card bill. The popularity of the dyno and tuning for numbers is driven by the fact that the "Tuner" can quickly make changes to the fuel & timing maps on his keyboard to affect change, then immediately make another dyno run. For you, you'll be doing a dyno pull, then to change your timing curve you'll pull the distributor, change out springs, put it back in and set timing. To change fuel you're pulling the top off the carb, changing jets, putting the top back on, all while your paying for dyno time.

I'd dial in the fuel by making a WOT run through the gears, shutting down to coast to a stop and reading the plugs. Check around the old mechanics shops and find one that has a distributor machine and you're done - https://horsepowersports.com/distrib...ke-a-comeback/

I hope you'll come back and let us know what you find when you get into the engine. 36 sedan gave you two good old school rules to follow....

Originally Posted by 36 sedan

JMHO, I really don't think your ring gaps were causing your trouble, unless they were significantly larger than you posted. In my youth (a long, long time ago) I ran some pretty worn out motors, a few had enough blow by to lay out a smoke screen and oil slick out the tail pipes, yet not enough crankcase pressure to blow out gaskets.

When you tear it down look it over closely, I believe there's more to this story than what meets the eye.

Also, I think you are a little confused on what a windage tray does, it does NOT reduce blow by or crankcase pressure, generally they are good at minimizing aeration of the oil at high RPM, which helps with a speedy return of the oil to the sump. There are lots of pro's and con's (and opinions) on windage trays.

I was told when I was young (many years ago) there are two phrases that apply to motor building and troubleshooting;
MOTOR BUILDING - Check, check, check, MAKE MISTAKES less, less, less
TROUBLESHOOTING - Test, test, test, SPEND less, less, less

I'll be looking everything over to the best of my ability, trust me. I don't think the extra gap was necessarily the cause either. But I'm sure reducing that gap a tad won't hurt. I want to t minimize the smoking.

Since I'm not incredibly knowledgeable of this stuff, I'm debating sending the crank, rods, and bearing, to a machine shop so that can measure them with the proper tools.

I know a windage tray doesn't reduce blow by, but like you said, it does reduce aeration of the oil, which from my understanding would keep pressure down. Maybe not, but still. I'm planning on revving this engine out to 7k so it seemed like a good idea.

Originally Posted by rspears

IMO you'll be spending, and wasting a LOT of money with your plan to rent dyno time, and you won't gain anything from it but an empty wallet or big credit card bill. The popularity of the dyno and tuning for numbers is driven by the fact that the "Tuner" can quickly make changes to the fuel & timing maps on his keyboard to affect change, then immediately make another dyno run. For you, you'll be doing a dyno pull, then to change your timing curve you'll pull the distributor, change out springs, put it back in and set timing. To change fuel you're pulling the top off the carb, changing jets, putting the top back on, all while your paying for dyno time.

I'd dial in the fuel by making a WOT run through the gears, shutting down to coast to a stop and reading the plugs. Check around the old mechanics shops and find one that has a distributor machine and you're done - https://horsepowersports.com/distrib...ke-a-comeback/

I hope you'll come back and let us know what you find when you get into the engine. 36 sedan gave you two good old school rules to follow....

I guess I should elaborate, I was going to do as much "tuning" as I could on the street before taking it to a dyno. My tuner guy does 75 dollars for 2 runs, and I want to do it just for my own satisfaction to know how much power I'm making, (expecting 500 crank). He won't even touch the carb, so no worries about paying for that.

I have an AFR gauge installed in the car, and if I can find someone with this distributor machine like you're talking about, I feel like I should be able to get fairly close to max power.

Originally Posted by NegativeZero

if I can find someone with this distributor machine like you're talking about, I feel like I should be able to get fairly close to max power.

I'll echo Rogers comments above, use the money for a good timing light instead.

Here's a link to an article I wrote for my car club a while back that will show you how to adjust and set your timing;
http://www.boyxunderthehood.com/wp-c...ERFORMANCE.pdf

Back to the original problem.. excessive pressure causing seal failure(s).
Back in this thread you mentioned that it only happens at 6K rpm or above. So my new theory is your probably running a high volume oil pump and at that high rpm your pumping oil up into the heads, flooding them and this causes a "trap" the pressure has no place to go. So it seeks a weakness. A loose fitted seal, or the Chinese wall ... It's called a windage tray because it "breaks" the wind shear or turbulence around the spinning crankshaft, this allows the oil to get out of the "wind" and settle to the bottom, where you can pump it back for another cycle.

My other thought is your selection for the ring end gap is excessive. If you aren't running boost, don't worry about building a motor for the added boost pressures. You said it yourself, rings are cheap. Build the motor for the duty it will perform, not for what you "want someday"...

And another thought, drop some of the bearing caps.. the ring materials went somewhere! Find it before you close the motor up.

My last thought.. a "guy" with a dyno, who can't handle a carb.?.? He is NO tuner! But that's my opinion I guess. You know a carb has like 2 moving parts right?? 36Sedan has a couple of great write-ups posted around here.. The link above from him is a keeper! Hint /Hint... PRINT IT! LOL.

Mr. Spears. At the bottom of your linked page it says this ...
quote;
"UPDATE: Looks like they’re out of business.

Link: King Electronics out of business

King Electronics has them for sale on eBay No longer available

Posted on October 12, 2011
Filed Under: Garage workshop, Made in America, Shop tools"