548 CI BBC Advice

[statsystems]

Where there is no carbon, there is no fuel. It's not fuel wash, it's the absence of fuel.

Really, interesting, how can I confirm that? Engine builder said wash. I can get a pic of the Pistons if that would show
more info.

It has been written/discussed/flogged etc for a while now. IIRC, Darin Morgan posted some stuff on his web site that showed on a wet flow bench that there is no fuel there.

Also, Harold Bettes talks about it in his book that I can't think of the name of right now. Damn. Any way, he discusses it.

It's almost impossible to kill myths like this.

If it's clean you don't have fuel there.

[TBART1970]

Where there is no carbon, there is no fuel. It's not fuel wash, it's the absence of fuel.

Really, interesting, how can I confirm that? Engine builder said wash. I can get a pic of the Pistons if that would show
more info.

It has been written/discussed/flogged etc for a while now. IIRC, Darin Morgan posted some stuff on his web site that showed on a wet flow bench that there is no fuel there.

Also, Harold Bettes talks about it in his book that I can't think of the name of right now. Damn. Any way, he discusses it.

It's almost impossible to kill myths like this.

If it's clean you don't have fuel there.

Should I be concerned, or how do I fix it?

[Newold1]

TBART1970

You are obviously a newbie on Speedtalk so I will start by saying welcome.
If you are trying to get some good more exact advise and discussion on your engines issues you need to start by posting some more complete specs and information on the build.

It would also be nice to know some specifics on your Holley EFI system, especially the ECM model and information on the tune in the ECM.

Couple of suggestions. Looking at the dyno sheet, my comments there are parallel with others on this post that the camshaft is the part that is peaking your power in the mid 5000rpm range and not the right design for best power and torque for this combination. Please post the complete cam specs that include LSA and intake center line. We also need to know the ratio on your rockers. My other comment is that you should not do dyno power pulls with the engine coolant temp at 125 degrees! If that was the real block temp you were hurting the engine at those temps on dyno power pull loadings.

It is pretty obvious that your engine is right at the safe spot on oil pressures at top rpms but that can be a result of a lot of oil system issues. Possible that if engine were warmer where it should have been for the test, the oil pressure could have been even lower? What oil and viscosity was being used? What oil pump? This looks to be an aftermarket block, not sure of brand but you can enlighten us on that, as well as the history of the engine if any.

It is also pretty obvious with the low use to that point that the engine is burning oil and there could be multiple reasons but most would suspect ring issues or bore finish reasons. What are the specs. on the rings, piston to bore clearance, how were cylinders bored, honed and final finished?

As others here have said, good leak down percentages alone are not a total determiner of proper ring function. I've seen BBC engines where the engine was having oil control issues in the cylinder and the leak downs measure 2-3% and found that someone had installed the second ring upside down an it happened to be a napier and it was pulling a lot of oil up below the top ring. the top ring was a good seal and leak downs were fine but the top compression ring could not keep up with the excessive oil control it was trying to measure. Same thing for oil ring package, could be wrong tension, installed wrong , etc.

As for your lifter issues, that can be a bunch of reasons, ie: lifter bore clearance, small base circle size allowing lifter oil passages to drop below bottom of lifter bore, to low of oil volume or pressure to lifter galleys, etc. , etc.

I am going to say something here that may rub wrong to you and maybe others. I realize your engine builder is a friend and you want to be a considerate owner to him as a friend. Not being privy to all your and his discussions of these problems I cannot know the real content and meaning of the discussions but I can say this: If your friend builder machined, assembled and delivered this engine to you pretty much ready to run, then he should take responsibility for the build.
If I built this engine and it had these issues, I would have you return it to me, carefully examine and explore simple checks and if necessary complete disassemble the engine and find the problem and let you know directly that either a part or parts failed, or I SCREWED UP ON MY BUILD! We don't know yet here the detail of this build and what total part your friend builder took part in, but we should so we can help give you some good advise of where to go from here. Good engine builds usually don't have this many major issues if careful proper methods were used and good parts were properly used.

You are right to take the approach to find the issues and problems and then go back together with a good build!

Hope the good people here on Speedtalk can help you find and correct your problems. thank you for giving us the chance.

What I can say here is don't go buying and replacing a group of parts here until you isolate all the total issues and find good fixes for all of them.

[TBART1970]

TBART1970

You are obviously a newbie on Speedtalk so I will start by saying welcome.

Thanks, and thanks for posting.

If you are trying to get some good more exact advise and discussion on your engines issues you need to start by posting some more complete specs and information on the build.

OK I agree.

It would also be nice to know some specifics on your Holley EFI system, especially the ECM model and information on the tune in the ECM.

HP, what would you like to know ( I am a newbie with injection so be patient, took a long time to get to this point and I still have tons to learn).

Couple of suggestions. Looking at the dyno sheet, my comments there are parallel with others on this post that the camshaft is the part that is peaking your power in the mid 5000rpm range and not the right design for best power and torque for this combination.

Dynoed with small carbureted intake and 850 cfm carb, which I said affected it, although the cam is still too small.

Even the new cam is too small? I thought it needed more lift, engine builder said more duration, maybe both?

Please post the complete cam specs that include LSA and intake center line. We also need to know the ratio on your rockers.

1.7 Jesel sportsman rockers. Cam cards are posted. Do they not show up, or missing info?

My other comment is that you should not do dyno power pulls with the engine coolant temp at 125 degrees! If that was the real block temp you were hurting the engine at those temps on dyno power pull loadings.

Engine builder said that also, I was not privy to that info at the time. I said next time due to oil temp/pressure I want it hotter.

It is pretty obvious that your engine is right at the safe spot on oil pressures at top rpms but that can be a result of a lot of oil system issues. Possible that if engine were warmer where it should have been for the test, the oil pressure could have been even lower? What oil and viscosity was being used? What oil pump? This looks to be an aftermarket block, not sure of brand but you can enlighten us on that, as well as the history of the engine if any.

Issues should be good to go on pressure, first pump was Moroso billet pump, standard volume, dyno intake and dist. In the car Injected intake, different dist. Had pressure problems from beginning. Pulled the engine put in Titan gerotor pump, slightly better but still an issue. Titan pump has a different drive at the pump and I made the mistake twice of not checking the distributor/ gear / galley alignment. Mismatched parts and trying to solve it in the car. I will take the blame, my builder is helping me fix this. I have every confidence in his ability to hone the bores and build this thing again. Although he should have been more on top of checking things I had no idea was going to be an issue. He as well as me assumed (oh boy) that the intake/ distributor would not be an issue. Bowtie block, brand new, never should have went right to 4.600 (someone was going to ask why eventually).

It is also pretty obvious with the low use to that point that the engine is burning oil and there could be multiple reasons but most would suspect ring issues or bore finish reasons. What are the specs. on the rings, piston to bore clearance, how were cylinders bored, honed and final finished?

It is burning oil, not from the rings and such, but from the way my PCV system( if you want to call it that was set up). It was pulling in oil. That will be fixed.

I will have to get that info.

As others here have said, good leak down percentages alone are not a total determiner of proper ring function. I've seen BBC engines where the engine was having oil control issues in the cylinder and the leak downs measure 2-3% and found that someone had installed the second ring upside down an it happened to be a napier and it was pulling a lot of oil up below the top ring. the top ring was a good seal and leak downs were fine but the top compression ring could not keep up with the excessive oil control it was trying to measure. Same thing for oil ring package, could be wrong tension, installed wrong , etc.

Pulled it apart, bores looked like crap, metal in oil came from worn camshaft distributor gear.

As for your lifter issues, that can be a bunch of reasons, ie: lifter bore clearance, small base circle size allowing lifter oil passages to drop below bottom of lifter bore, to low of oil volume or pressure to lifter galleys, etc. , etc.

Lifter issue was because of oil pressure, lifter bore clearance was .0015". That is why I put in the solids to try and find the issue. Crower HIPPO, Morel HIPPO, Morel non HIPPO. Lower pressure with the HIPPO. Not much better with non HIPPO. Excessive Oil was not coming out from lifter bore with non HIPPO.

I am going to say something here that may rub wrong to you and maybe others. I realize your engine builder is a friend and you want to be a considerate owner to him as a friend. Not being privy to all your and his discussions of these problems I cannot know the real content and meaning of the discussions but I can say this: If your friend builder machined, assembled and delivered this engine to you pretty much ready to run, then he should take responsibility for the build.
If I built this engine and it had these issues, I would have you return it to me, carefully examine and explore simple checks and if necessary complete disassemble the engine and find the problem and let you know directly that either a part or parts failed, or I SCREWED UP ON MY BUILD! We don't know yet here the detail of this build and what total part your friend builder took part in, but we should so we can help give you some good advise of where to go from here. Good engine builds usually don't have this many major issues if careful proper methods were used and good parts were properly used.

You are right to take the approach to find the issues and problems and then go back together with a good build!

Hope the good people here on Speedtalk can help you find and correct your problems. thank you for giving us the chance.

What I can say here is don't go buying and replacing a group of parts here until you isolate all the total issues and find good fixes for all of them.

[/quote]

Why don't you tell me how you really feel. LOL doesn't rub me the wrong way at all. I need all the info I can get so I can tell him what I want done. I don't care if he gets a little mad at me at this point.
I take the blame for some of it, trying to fix it in the car, dealing with oil pressure issues and trying to learn injection at the same time so I could drive it. Bit off more than I could chew. I feel the issues have been pinned down and will be fixed, as for the cam????

I will finish this later. Thanks

[Newold1]

Thank you for the nice complete come back, specs. And explanations. Helps to understand where you've.been so we can hopefully help you get to where you need to be!

Sounds like the oil pump distributor fitment started the real mechanical and oiling issue and having that good old metal in the oil "ruining compound" did in the bores and other internals.

Yah, I like to start expensive aftermarket big blow ks at 5.560" and leave an owner with "meat" for repAirs and refreshes. You can take them to 4.620" but those walls are getting into distortion areas with higher power assets.

I don't know how much clearance your bores have now or how much metal is embedded if any in the piston s, but you may be able to clean up phone the bores and cleAn the piston . A new set of rings and bearings should be a "must do".

Your bearing clearances sound like they are tight enough to allow a nice repolish on the crank and go back together with just new bearings.

I know a lot of guys are in love with exotic wet oil pumps, I'm not!

Just get a good Moroso high volume steel pump in there, get the right pump drive zhat and the proper gear on the type of cam gear that your cam comes with.

Tell us here on SpeedtLk how you want this engine to perform and where you wNt hour power to occur rpm wise and the torque figure you would prefer and a good EFI cam spec will come your way.

Then you can put a correct engine on the dyno and tune that EFI system correctly.

By the way pleAse give us a description of the injectors, intake manifold and throttle body type and size. You need this info to help with a camshaft selection.

[TBART1970]

Thank you for the nice complete come back, specs. And explanations. Helps to understand where you've.been so we can hopefully help you get to where you need to be!

Sounds like the oil pump distributor fitment started the real mechanical and oiling issue and having that good old metal in the oil "ruining compound" did in the bores and other internals.

Yah, I like to start expensive aftermarket big blow ks at 4.560" and leave an owner with "meat" for repairs and refreshes. You can take them to 4.620" but those walls are getting into distortion areas with higher power assets.

Block was Metalaxed, torque plate obviously, block has been rehoned, he said it took, now don't quote me on this , half a thousandth or so to clean up the bores. Pistons had some scoring but not bad, no signs of detonation. I have to find out the piston to bore clearance, but I know he runs them tight.

I don't know how much clearance your bores have now or how much metal is embedded if any in the piston s, but you may be able to clean up phone the bores and clean the piston . A new set of rings and bearings should be a "must do".

New rings and bearings. Bearings actually looked good considering.

Your bearing clearances sound like they are tight enough to allow a nice repolish on the crank and go back together with just new bearings.

I know a lot of guys are in love with exotic wet oil pumps, I'm not!

Just get a good Moroso high volume steel pump in there, get the right pump drive shaft and the proper gear on the type of cam gear that your cam comes with.

My builder is with you on the pump, I have a fresh Titan pump, it was not cheap. I need to keep it. I always had the correct gear on the distributor, but when you mismatch the alignment it doesn't like it and eats parts LOL.

Tell us here on Speedtalk how you want this engine to perform and where you want your power to occur rpm wise and the torque figure you would prefer and a good EFI cam spec will come your way.

Then you can put a correct engine on the dyno and tune that EFI system correctly.

When it was first built I was expecting 700 hp and 650 ft lbs. Not looking to beat the world, it is a street car. Where would you put the compression at, do you think the new cam is that bad? Do you think the carbon pattern is bad? We are going to up the compression , mill down the domes for flame front and machine the heads to reduce chamber size. I don't want to get too carried away with milling things because of issues with intakes and headers. 2" super comps by the way, 3 inch full exhaust with crossover

By the way please give us a description of the injectors, intake manifold and throttle body type and size. You need this info to help with a camshaft selection.

66 lb Holley injectors, Edelbrock Pro-Flo XT intake with 90mm throttle body.

[TBART1970]

I called bullet cams said that it is a hydraulic core with a solid roller profile

[wyrmrider]

Uh what exactly is a hyd core and how is that any different than a solid core?
wait while I pull my pants further up my boots
it's getting deep

[TBART1970]

Don't know.

[In-Tech]

Probably means it's an austempered iron core instead of a steel billet.

[statsystems]

Again, this is why I say don't screw with hydraulic roller lifter stuff.

Most guys think it's going to be quiet like a passenger car and make power like a solid roller.

This is a no win situation. I'm not a fan of iron cores and roller lifters.

[TBART1970]

Probably means it's an austempered iron core instead of a steel billet.

Billet core. Let's​ pretend I never said anything about hydraulics. Took out the hydraulic cam and ordered full solid roller billet.

[TBART1970]

Again, this is why I say don't screw with hydraulic roller lifter stuff.

Most guys think it's going to be quiet like a passenger car and make power like a solid roller.

This is a no win situation. I'm not a fan of iron cores and roller lifters.

Can't be any louder than the stuff that came out.

[statsystems]

Again, this is why I say don't screw with hydraulic roller lifter stuff.

Most guys think it's going to be quiet like a passenger car and make power like a solid roller.

This is a no win situation. I'm not a fan of iron cores and roller lifters.

Can't be any louder than the stuff that came out.

That's what I'm saying. They hydraulic isn't quiet like people think. Might as well run a solid.

[Newold1]

Before we get into hydraulic versus roller cam conflicts, lets talk about your power and torque expectations.

The horsepower expectation you have in my opinion is very achievable and the power limiting factor on this engine will come from, believe it or not, the intake manifold and throttle body. The CFM this engine will consume at about 6000 - 6500 rpms with a good camshaft will either eclipse or come very close to exceeding what a 90 mm throttle body on that small plenum EFI intake from Edelbrock may be able to supply. This manifold is really about a 600-maybe 650 hp combination on a 548 BBC with good compression, good camshaft and a good set of flowing heads. The challenge here may be getting it to a point where it will flow the air required, You might do some research as to what others have achieved with this setup as I have no direct experience with this setup and I am just doing some simple calculations on PipeMax and its' may be a challenge with what I know a 90mm throttle body can flow. It might help you if you happen to be able to identify the heads here and specs. as well as any flow data you may have. It will also help with a camshaft choice.

As for compression increase and combustion chamber burn patterns, its' my opinion that compression in this engine can only help to a point. Most likely the Holley EFI control system you have has some great tuning capability for both fuel and timing and that being said I don't think its unreasonable to try to use 10.5 to 1 in this aluminum headed BBC in this street type use as long as you have 93 octane fuel available in your area. If you stay with your current pistons then obviously you've got to decrease combustion space CC's to get to that point and that might be doable but it will take some work depending on your dome volume now, deck height of piston when reassembled, head gasket thickness.
Can you give find and give some input here as to those questions so a compression calculation can be done to determine where the engine is now on compression (really) and where with some simpler changes may get close to a higher compression ratio.

Also keep in mind that some compression changes might be doable with camshaft design as your requirements on power and rpms leave a little more flexibility of where intake closing and exhaust openings can be adjusted to deliver more dynamic compression and sort of lessen the effects of your current lower cranking compression.

As for milling heads and intake to fit that's a lot more expensive and involved and I am not sure there is enough easily possible there to make a real cost versus benefit. I would not advise going there unless you feel you must.

Glad to hear the oil pump distributor conflicts did not totally wipe things out with metal. Have you carefully determined how this took place and what the exact cause was. Your post on that is a little short on the details.

When you first fired this engine up with either pump what was your cold and hot oil pressures at idle and at higher rpms when measured on your gauge. When did it start dropping and if so did it drop significantly? Did the lifter and valve train noise show up initially or did it happen after the oil pressure drop?

Another piece of info missing here is the specs. on your valve springs - spring pressures closed and open, type beehive versus duals and sizes.

I am not a huge fan of hydraulic roller camshafts in some high performance racing big block applications, but in extended street use and certain other moderate power and rpm applications they are fine if the camshaft is a good build and design, good hi-performance hydraulic roller lifers and proper valve train matches are used. This is even more true when a lower rpm use such as yours is being built and reasonable spring pressures are usable in the application. So don't throw in the towel on a hydraulic roller here yet. If you can use one well they are definitely going to be longer lived and easier to maintain.

Hope some of these questions and thoughts here can help you get to a better place with your re-build and end up with a nice satisfactory result.

Lots to learn here on both sides of this post!