I finidhed the disassembly, no smoking guns. Double checked the degreeing of the cam and checked the duration of intake lobe as well as all 16 lobes for lift while still in the motor, They were almost all within .005 in. from spec. Could have been even closer but I was just checking that none were really off. I did not check for timing of each lobe. I don't even know how I would attempt that. Nor did I check duration for the exhaust. Tells me that nothing was defective with the cam, the timing or the valvetrain. As I have said previously, the car ran well, I just think it has more to show. I am trying to do this methodically. I have extensively refined the EFI tuning, checked fuel delivery, adjusted various timing events. The last 2-3 items are, Get a new cam (on the way), New converter, ??.
When good is not enough, Camshaft time again.
- Thread starter Kent mosby
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My intuition on this (key word intuition it could be wrong) is the problem area isn't really the cam. While I do understand the desire to address the small-ish cam, I don't think you're gonna go from current (400whp) to desired (550 whp) with a cam swap.
That might be the case if say you were sporting a really small...like a stock cam. But your starting point of 250+ degrees duration isn't exactly a puny stick.
I'm leaning towards converter being wrong. And making more power against a converter you may already be blowing through... that's not gonna make the situation better.
Carry on. We're all interested...
That might be the case if say you were sporting a really small...like a stock cam. But your starting point of 250+ degrees duration isn't exactly a puny stick.
I'm leaning towards converter being wrong. And making more power against a converter you may already be blowing through... that's not gonna make the situation better.
Carry on. We're all interested...
mayhem
Well-Known Member
What's the new cam?
You will find out if the cam was the problem,but not the converter or the fuel injection.
The new cam will be. 250/256-112, .550/.560. With 1.5RR but we will be using 1.6rr. So lift will be .587/.597 and duration will have a small increase as well. The rockers were 440 source aluminum rockers so unsure quality as to amount of lift was actually being provided. I am not seeking 550 hp at the rear wheels, btw. I would like to see at least 450 and still keep the street manners and drivability. Of course once I get to low 11s regularly, who knows what will be next.
Would have been nice to drop a carburetor on there with your existing camshaft to see if it wakes up, taking the electronic fuel injection package out of the equation.
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Solid roller. Carburetor. A bigun.
I am not sure why so many are pointing at EFI. I got it even though it is more expensive because it can be tuned by computer while looking at datalogs and on a laptop while driving. Whereas a carburetor you have to have knowledge of jet sizes, carb types, sizes, AFR, etc. All the while trying to control timing events but not having the carb and ignition talking to each other. Many of you have extensive experience in tuning carbs and can do wonders with them. I do not have that experience, yet I can program from computer data. Like many have said, I cannot expect to get 150 hp from a cam change. True that. I do not believe that any carburetor would get me 150 more horsepower. With an experienced tuner, there may be some gains. Maybe not. I have not seen clear evidence that carbs make significantly more power. Engine masters did a show on it in season 1 and carb did not make more hp. My efi supports 650 hp stock and 1250 with forced intake, That should suffice.. Can someone please provide info comparing Holley super sniper or comparable EFI vs a carburetor. If the cam swap fails, I would consider a carb change. One thing at a time. BTW, cam is already out of the car and new one is being made so there is no going back.
Rusty, Solid roller was not the option because the street reliability is not up to par with the SFT.
Thanks for all the help and suggestions. I will keep learning along the way.
Rusty, Solid roller was not the option because the street reliability is not up to par with the SFT.
Thanks for all the help and suggestions. I will keep learning along the way.
I was cautious of that EFI setup when you first started building this.
One way to learn and experience what it's all about.
Aftermarket EFI
While some view aftermarket EFI as a worthwhile upgrade for drive ability and efficiency, others caution that it can be a costly and complex endeavor with potential pitfalls.
* * * * *
One way to learn and experience what it's all about.
Aftermarket EFI
While some view aftermarket EFI as a worthwhile upgrade for drive ability and efficiency, others caution that it can be a costly and complex endeavor with potential pitfalls.
* * * * *
Saying a solid roller isn't up to reliability tells me you're still in the past. They certainly ARE reliable for every single day usage. You may be reading, but you're not comprehending. I said a STREET SOLID ROLLER LOBE. There's the difference. A street solid roller LOBE is much less aggressive and will last as long as you want it to. Not my car. Not my money. That's cool. I hope your undercammed 512 works well.
As to the EFI, I don't think we're necessarily pointing the finger. We're more saying maybe TRY a carburetor as a temp diagnosis tool and "see what happens". I'm in total agreement with everyone that the camshaft AIN'T gonna give you what you're looking for. Even switching to a solid roller. Having said that, that's what that engine needs with the heads and cubes. I hope you find it, whatever it is. But remember this. As you throw all our recommendations back in our faces, you DID come here asking for help and advice. Good luck buddy. I hope you get it figured out.
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JMO, no chance I run that set up with less than 600-650 lift.
That cam change is minor IMO. Some more data acquisition prior to tear down, like the vacuum at high RPM during a full run in each gear would have told you a bunch. Supporting 650hp is not the same as allowing sufficient airflow into the engine. Thus, my suggestion regarding the vacuum reading in high gear full throttle top of pull. Marathon runner having to run breathing through only a straw.
Hope it works. Find someone with a true 1000-1050 cfm carb that is good if these change results aren't up to snuff.
Good luck with it and have fun, that's what counts.
That cam change is minor IMO. Some more data acquisition prior to tear down, like the vacuum at high RPM during a full run in each gear would have told you a bunch. Supporting 650hp is not the same as allowing sufficient airflow into the engine. Thus, my suggestion regarding the vacuum reading in high gear full throttle top of pull. Marathon runner having to run breathing through only a straw.
Hope it works. Find someone with a true 1000-1050 cfm carb that is good if these change results aren't up to snuff.
Good luck with it and have fun, that's what counts.
Mopar Purple P4120662 when all else fails, it has been written for all to see.
I apologize if I came across as throwing your recommendations back in your faces. That was certainly not my intent. I only wanted to explain why I decided to do efi in the first place. My lack of knowledge. Along this way I have tried to explain my methodology which is to change the cam first. Sort that out. Then assess what else could be improved. I never negated anyone’s other suggestions and have indicated that I will put them on the list of improvements, TC, Carb were ones I have said I will change if the results of the cam change do not satisfy. My original intent was what type of cam and specs of such. I tried to emphasize that street manners were important and that expectations were not to maximize power at the expense of street manners. Striking the right balance was my goal.
If you are saying to run a solid lobe with a solid flat tappet lifter, I have never heard that. Sorry for my not comprehending. I went away from a solid roller cam because of reliability issues with the roller bearings during extended street use. They are great for max power during racing but many street miles have lead to issues. If my knowledge is flawed with old info, again, sorry for my naivety.
Yes I did come asking for advice and I appreciate all the help given along the way. I had hoped that just because I chose in the past a different route and then tried to explain my decision that I did not come across as ungrateful. I was wrong.
Fwiw, not an excuse but an explanation, I have Asperger syndrome. If you are unaware of it, it is a form of autism that prevents me from “reading the room”, or form discerning what is meant by someone’s connotation or meanings. I interpret things very literally and it means that my responses are not filtered with the normal rationale that normal people do. Evidently, I misinterpreted the responses yet again. Sorry for that. Still trying to get through this life without offending people. Not very successfully.
I should probably close this thread before I offend anyone else. Sorry for the offense I have caused you and others.
Not to worry.
One of my autobody instructors back in the 70s had this saying: Make a decision and act upon it.
A person is going to find out soon enough if it was right or wrong, then collect things up and move on to the next logical step.
Definition of a successful person > someone who is right 51% of the time. Lessons learned are where the real gold is. If a person had not tried, they never would have found the gold.
__________
Old Driveway
Possibilities >
Hmmm.....?
☆☆☆☆☆
One of my autobody instructors back in the 70s had this saying: Make a decision and act upon it.
A person is going to find out soon enough if it was right or wrong, then collect things up and move on to the next logical step.
Definition of a successful person > someone who is right 51% of the time. Lessons learned are where the real gold is. If a person had not tried, they never would have found the gold.
__________
Old Driveway
Possibilities >
Hmmm.....?
☆☆☆☆☆
No sir. Solid roller, solid ROLLER lifters with matching springs. You will need correct length pushrods. It's clear you have tunnel vision on this and that's fine. There's always more then one way to do things. You'll get it licked I'm sure.
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I think what Rusty is saying is " solid roller, solid roller lifters" He will correct me if that is wrong.
Correct. The entire conversion, including all needed parts.
You can roller lifters, sol or roller, with a bushing [ not needle rollers ]. They can cost more, that is what I use. I have Isky lifters, been in the engine about 15 yr; at the time I bought them, they offered three different types of bush material.
PRH
Well-Known Member
If using premium SR lifters, the swap to a SR from a SFT is about $3000.
-cam
-lifters
-pushrods
-oil pump drive gear
-thrust button
-roller springs
-retainers
-locks
-cam
-lifters
-pushrods
-oil pump drive gear
-thrust button
-roller springs
-retainers
-locks
I know I keep beating this dead horse. But you have a Hughes 3000 stall converter behind a 500 inch BB with TF heads. Your dyno guy says it's "stalling at 4500 rpm". To me that big a stall increase just screams blowing through the converter.
Also noteworthy, the Hughes 3000 is rated for 500-550 hp.
You can spend all the money in the world on cams and valvetrain, make more power, and never even know it if the TC isn't up to the task.
I'll shut up about this now. But that TC is for a mild warmed over 440, not a TF headed 500 incher.
Also noteworthy, the Hughes 3000 is rated for 500-550 hp.
You can spend all the money in the world on cams and valvetrain, make more power, and never even know it if the TC isn't up to the task.
I'll shut up about this now. But that TC is for a mild warmed over 440, not a TF headed 500 incher.
BSB67
Well-Known Member
Just did a quick price check for the stuff in my street car and if purchased today it would be right at that $3000, plus shipping and taxes.
PRH
Well-Known Member
Yup……. It’s real money these days.
And to keep a decent level of reliability for street use, there isn’t anything on the list you can scrimp on.
Cam on the way.
Lifters out for refacing
Rockers on the way.
Just waiting for parts to get here. I might be able to get this done before too much snow arrives. If so I will take it to the chassis dyno to see where we are.
The more I think about this, the more I want to address the torque converter this winter. Who is the go to for this? @Mean416 the guy who said it is stalling at 4500 was Andy Finkbeiner who evaluated the datalogs from a dragstrip run. The dyno guy said it flashed or stalled (can't remember which) at 3500 during the runs way back when they were done. Might do the cam first, chassis dyno where we are. then converter and see how that changes things.
Lifters out for refacing
Rockers on the way.
Just waiting for parts to get here. I might be able to get this done before too much snow arrives. If so I will take it to the chassis dyno to see where we are.
The more I think about this, the more I want to address the torque converter this winter. Who is the go to for this? @Mean416 the guy who said it is stalling at 4500 was Andy Finkbeiner who evaluated the datalogs from a dragstrip run. The dyno guy said it flashed or stalled (can't remember which) at 3500 during the runs way back when they were done. Might do the cam first, chassis dyno where we are. then converter and see how that changes things.
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