347 EFI Low Power

TOOLOW91

If you're the village idiot what's that make me?
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My bad, Im new here, didnt say the other posted haha.

They told me 10.5:1 compression

Cam: Elgin E1836P
Intake Valve Lift: .542"
Exhaust Valve Lift: .563"
Advertised Intake Duration: 286
Advertised Exhaust Duration: 289
Intake Duration @ .050": 224
Exhaust Duration @ .050": 232
Lobe Separation: 112

93 Octane

I'm not sure on timing as I had someone time it, he just told me to put it at 10 when I brought it and he added timing through the tune

So, the converter is supposed to be a 2500 stall but the car only stalls at 1700-1800, second time this has happened with a converter for me
The car only stalling to 17-1800 sounds like it’s got a stock converter . This thing needs to stall like 2800-3000 ish given it has a decent cam and it’s short in power .

Stalling 17-1800 means it’s way to tight . I have a built FB aod in my own car with a custom PTc . Our combos are much different though.


Either way I think your lack of power is in your converter . The 5 mm in throttle body is not going to help .

Sure porting the heads will always help , correct springs are key .

But the converter flashing at 17-1800 it may as well be stock.
 
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The car only stalling to 17-1800 sounds like it’s got a stock converter . This thing needs to stall like 2800-3000 ish given it has a decent cam and it’s short in power .

Stalling 17-1800 means it’s way to tight . I have a built FB aod in my own car with a custom PTc . Our combos are much different though.


Either way I think your lack of power is in your converter . The 5 mm in throttle body is going to help .

Sure porting the heads will always help , correct springs are key .

But the converter flashing at 17-1800 it may as well be stock
I have changed the converter twice, both were stated to be 2500 stall and both stalled at 1800.
 

TOOLOW91

If you're the village idiot what's that make me?
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I have changed the converter twice, both were stated to be 2500 stall and both stalled at 1800.
Who’s off the shelf converter are you buying ? You obviously need to talk to a converter company ans tell them what you have - what you’re seeing and what you need .

Like I said I feel you need to be around 2800-3k ish

Call dusty at ptc or Pete at circle d ( formerly at Hughes)
 

TOOLOW91

If you're the village idiot what's that make me?
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I have changed the converter twice, both were stated to be 2500 stall and both stalled at 1800.
What made you change it the first time ? Was it already down on power and didn’t stall where it should’ve ?

The dyno guy should’ve seen that as problem number 1 right there in my opinion.
 
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Who’s off the shelf converter are you buying ? You obviously need to talk to a converter company ans tell them what you have - what you’re seeing and what you need .

Like I said I feel you need to be around 2800-3k ish

Call dusty at ptc or Pete at circle d ( formerly at Hughes)
Yeah I wanted to get a 3k and everyone was like no don't do it you will hate how it drives, well guess what I hate the supposed 2500 stalls.

I will definitely be calling and getting it fixed in the future
 
What made you change it the first time ? Was it already down on power and didn’t stall where it should’ve ?

The dyno guy should’ve seen that as problem number 1 right there in my opinion.
The first 2500 stall I put in, my car would break the tires free at 1700 if I power brakes it, I swapped it when I got my trans rebuilt, does the same exact thing
 

TOOLOW91

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Yeah I wanted to get a 3k and everyone was like no don't do it you will hate how it drives, well guess what I hate the supposed 2500 stalls.

I will definitely be calling and getting it fixed in the future
Yeah you need to talk with someone who specs converters to get what you need . My
Coupe acts like a 3-3200 ish cruising . Guess what - it flashes to 5-5200 when you let it eat. Converter tech has come along way.
 
Yeah you need to talk with someone who specs converters to get what you need . My
Coupe acts like a 3-3200 ish cruising . Guess what - it flashes to 5-5200 when you let it eat. Converter tech has come along way.
You know and now that I think about it, it's probably because foot stall is way lower than what the rated stall is, my new valve body will have a trans brake which should help but still needs to be more like 3k.

Do you think that I should go up to 1 3/4 headers? Would be an easy bolt in
 

Noobz347

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[All] that :poo: up there plus... I wanted to draw some extra attention on getting the springs fixed up. I cannot recall any time when Chinese 'built heads' didn't need replacements. :shrug:
 
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Bullitt347

I have been doing it wrong this whole time
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The converter in my race car stalls to 6K
In your car it might make it to 3,500K
Take a 1,800 rpm converter, put into a higher powered car and all of the sudden the converter is at 2,500 rpm.
There is no set rpm a converter will "stall" to.
That is determined by the HP/Torque of the engine.
Matching the converter to the engine is important.
Buying a "rated" OTS converter is a fools errand.
 
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TOOLOW91

If you're the village idiot what's that make me?
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You know and now that I think about it, it's probably because foot stall is way lower than what the rated stall is, my new valve body will have a trans brake which should help but still needs to be more like 3k.

Do you think that I should go up to 1 3/4 headers? Would be an easy bolt in
1000 percent

Do you Have long tubes or shortys ?
 

TOOLOW91

If you're the village idiot what's that make me?
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The converter in my race car stalls to 6K
In your car it might make it to 3,500K
Take a 1,800 rpm converter, put into a higher powered car and all of the sudden the converter is at 2,500 rpm.
There is no set rpm a converter will "stall" to.
That is determined by the HP/Torque of the engine.
Matching the converter to the engine is important.
Buying a "rated" OTS converter is a fools errand.
Nailed it !
 

rednotch

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Also just curious, what would show in the curve if the springs are too light. It's possible he bought them unassembled and installed his own springs
Sharp drop offs would show loss of valve control in upper rpms, it depends what you want out of the car but I wouldn't expect much from just slightly bigger bolt ons like a throttle body or intake pipe If its a driver and you just want more power. a bolt on a power adder vs buying all new top end and reworking the heads might be cheaper, a loser converter probably won't show a gain on the dyno but will improve et and drive feel.

Mine was a straight up budget used/cheap parts build to use as a driver and toy that I had like 7k total into the car when done but I have years of left over parts for these cars and it was before vthey covid drove prices on everything way up. Car looked like a beater but was fun and had working a/c. Didn't want to gut it so needed decent power to run what I considered fun.. It had a badly missed matched combo when I picked up, 347 with stock heads and a tfs street intake, shorty headers and a wc t5, also had a bunch of suspension and brake parts. It was ugly and slow and had lots of electrical issues., was so slow I never bothered to run it before tearing it apart.

I actually had the same cam for it, its still in my parts pile, found the other one cheap. It ended up with a ported Holley systemax, 80R accufab t body, 4" pipe, 80mm maf, heads where same casting as yours but ported and lsx dual style spring with arp studs and old set of 1.72 scorpion rockers I had laying around, exhaust was cheap 1 7/8" ebay ls swap longtubes, took a few cuts to fit with a t5 /spare tko I put in later, 3" ebay x pipe kit and some ebay 3" Jones knock off maxflow mufflers, one nice thing i liked about the 3" bolt spacing on those heads . Tuning was locking the timing and fuel pressure on a stock a9l. Went 10.80 @124 on motor and drove decently for what it was, ran pretty decent on nitrous too but the t5 didn't last long.
 
Sharp drop offs would show loss of valve control in upper rpms, it depends what you want out of the car but I wouldn't expect much from just slightly bigger bolt ons like a throttle body or intake pipe If its a driver and you just want more power. a bolt on a power adder vs buying all new top end and reworking the heads might be cheaper, a loser converter probably won't show a gain on the dyno but will improve et and drive feel.

Mine was a straight up budget used/cheap parts build to use as a driver and toy that I had like 7k total into the car when done but I have years of left over parts for these cars and it was before vthey covid drove prices on everything way up. Car looked like a beater but was fun and had working a/c. Didn't want to gut it so needed decent power to run what I considered fun.. It had a badly missed matched combo when I picked up, 347 with stock heads and a tfs street intake, shorty headers and a wc t5, also had a bunch of suspension and brake parts. It was ugly and slow and had lots of electrical issues., was so slow I never bothered to run it before tearing it apart.

I actually had the same cam for it, its still in my parts pile, found the other one cheap. It ended up with a ported Holley systemax, 80R accufab t body, 4" pipe, 80mm maf, heads where same casting as yours but ported and lsx dual style spring with arp studs and old set of 1.72 scorpion rockers I had laying around, exhaust was cheap 1 7/8" ebay ls swap longtubes, took a few cuts to fit with a t5 /spare tko I put in later, 3" ebay x pipe kit and some ebay 3" Jones knock off maxflow mufflers, one nice thing i liked about the 3" bolt spacing on those heads . Tuning was locking the timing and fuel pressure on a stock a9l. Went 10.80 @124 on motor and drove decently for what it was, ran pretty decent on nitrous too but the t5 didn't last lon

Sharp drop offs would show loss of valve control in upper rpms, it depends what you want out of the car but I wouldn't expect much from just slightly bigger bolt ons like a throttle body or intake pipe If its a driver and you just want more power. a bolt on a power adder vs buying all new top end and reworking the heads might be cheaper, a loser converter probably won't show a gain on the dyno but will improve et and drive feel.

Mine was a straight up budget used/cheap parts build to use as a driver and toy that I had like 7k total into the car when done but I have years of left over parts for these cars and it was before vthey covid drove prices on everything way up. Car looked like a beater but was fun and had working a/c. Didn't want to gut it so needed decent power to run what I considered fun.. It had a badly missed matched combo when I picked up, 347 with stock heads and a tfs street intake, shorty headers and a wc t5, also had a bunch of suspension and brake parts. It was ugly and slow and had lots of electrical issues., was so slow I never bothered to run it before tearing it apart.

I actually had the same cam for it, its still in my parts pile, found the other one cheap. It ended up with a ported Holley systemax, 80R accufab t body, 4" pipe, 80mm maf, heads where same casting as yours but ported and lsx dual style spring with arp studs and old set of 1.72 scorpion rockers I had laying around, exhaust was cheap 1 7/8" ebay ls swap longtubes, took a few cuts to fit with a t5 /spare tko I put in later, 3" ebay x pipe kit and some ebay 3" Jones knock off maxflow mufflers, one nice thing i liked about the 3" bolt spacing on those heads . Tuning was locking the timing and fuel pressure on a stock a9l. Went 10.80 @124 on motor and drove decently for what it was, ran pretty decent on nitrous too but the t5 didn't last long.
I'm not worried about it being the fastest 347 out there, just want it to run as good as it can with the combo it has. I'm thinking I'll just get a 75mm TB and up the intake size from 3 to 3.5 and then put in 1 3/4 shorty headers, pretty sure my headers have a pinhole in them anyways. Also would rev hang be fixed with the new motorcraft iac?
 

revhead347

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The engine will only make as much power as the heads will flow irrelevant of displacement. Those numbers are pretty much spot on for the flow numbers on those heads.

Kurt
 
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rednotch

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[All] that :poo: up there plus... I wanted to draw some extra attention on getting the springs fixed up. I cannot recall any time when Chinese 'built heads' didn't need replacements. :shrug:
Liberty is just a jobber parts house from the Philly area, hence the name.. You can order Pac valvetrain thru them if you wanted and the heads bare or complete plus you can swap springs without pulling the heads pretty easy.. I would ask the builder how he ordered them and what springs it used either way. The as cast port tends to be in the 250cfm range on most benches, its the exhaust that's weak, a box stock edelbrock intake is like 225 cfm tops, a better intake or even porting would help more then a t body or intake pipe. My heads where like 286/188 in my lift range and I'm no porter. I honestly expected to run over the crank in that car but haven't hurt it yet. Rev hang would be in the tune, fords old IAC ain't the best set up.