Thread: Too much crankcase pressure, novice engine builder

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Originally Posted by jerry clayton

and do you know what your timing is set to???????? did you verify the tdc mark ?

TDC mark is verified. I don't understand timing enough to give you an accurate number on "what it's set at". Between the vacuum advance, mechanical advance, and just regular setting. I'm not 100% sure. My strategy largely reliant on looking at what other's did on the internet and adjusting it until I didn't hear any knock anymore. I do have a timing light, but this is why I am planning on going to a tuner since I'm not at all familiar with this.

Originally Posted by NegativeZero

My strategy largely reliant on looking at what other's did on the internet and adjusting it until I didn't hear any knock anymore. I do have a timing light, but this is why I am planning on going to a tuner since I'm not at all familiar with this.

You may have just found the problem! With the engine warmed up and running at idle unhook the vacuum line to your distributor and plug the hose (pencil or golf tee work good). With the engine at idle adjust the distributor position to your base timing with your timing light - I would start at 12 degrees before TDC for your SBC, tighten the distributor hold down bolt and recheck to be sure it didn't shift with tightening. You can rev the engine a bit to see with your timing light that the mechanical advance is working, then hook up your vacuum line and you're good to go.

Found it...

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!

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

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 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

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.

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

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.

Originally Posted by 34_40

My other thought is your selection for the ring end gap is excessive.
And another thought, drop some of the bearing caps.. the ring materials went somewhere! Find it before you close the motor up.

Fair points. I am reducing the gap this time around. Every piece will be removed from the block and cleaned well before placed back. As for the oil pump, it's an brand new OEM style pump. I still think excessive blow by was the main culprit here.

Originally Posted by 34_40

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.

As for my tuner, I'm sure he's fully capable of messing with carbs, he just gets enough business with fuel injection he doesn't have to mess with carbs. It's not worth his time and I understand

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"