Carb opinions 540's 700 hp...
06-13-2015 | 05:33 AM
#391
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From: Olmsted Falls,Ohio Marblehead,Oh
The reason someone would send a brand new carb to be gone over by a QUALIFIED carb shop is simple.
You do that to quantify that you have received what you were suppose to.
Same reason it's a good idea to have a qualified individual take apart and quantify brand new, out of the box, cylinder heads.
It does not surprise me in the least that these assembly line produced QFT carbs need looked at.
You do that to quantify that you have received what you were suppose to.
Same reason it's a good idea to have a qualified individual take apart and quantify brand new, out of the box, cylinder heads.
It does not surprise me in the least that these assembly line produced QFT carbs need looked at.
even cylinder heads in most cases would be fine just bolted on, I can't tell you how many sets of out of the box heads I have bolted on engines in 20 years with zero issues....apparently times have changed as to make sure its ok you gotta look yourself.... I did however have ZERO issues with my carbs.....
06-13-2015 | 08:11 AM
#393
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From: Traverse City MI
The reason someone would send a brand new carb to be gone over by a QUALIFIED carb shop is simple.
You do that to quantify that you have received what you were suppose to.
Same reason it's a good idea to have a qualified individual take apart and quantify brand new, out of the box, cylinder heads.
It does not surprise me in the least that these assembly line produced QFT carbs need looked at.
You do that to quantify that you have received what you were suppose to.
Same reason it's a good idea to have a qualified individual take apart and quantify brand new, out of the box, cylinder heads.
It does not surprise me in the least that these assembly line produced QFT carbs need looked at.
Good point but your digging pretty deep to try and show some people up
What you forgot though is the carbs get "quantified" on the dyno, adjusted and tuned as necessary, then triple checked with an O2 meter in the boat
06-13-2015 | 08:26 AM
#394
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From: yorkville,il
The reason someone would send a brand new carb to be gone over by a QUALIFIED carb shop is simple.
You do that to quantify that you have received what you were suppose to.
Same reason it's a good idea to have a qualified individual take apart and quantify brand new, out of the box, cylinder heads.
It does not surprise me in the least that these assembly line produced QFT carbs need looked at.
You do that to quantify that you have received what you were suppose to.
Same reason it's a good idea to have a qualified individual take apart and quantify brand new, out of the box, cylinder heads.
It does not surprise me in the least that these assembly line produced QFT carbs need looked at.
and correct it.some people would be better off bying a crate motor instead of attempting to build it.
06-13-2015 | 08:42 AM
#395
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From: chicago
There's certainly no debating TAsteven's issue of blank restrictors installed behind his power valve, was a screw up.
And I can tell you from actual experience, just because you send a carb "specialty" shop, you cubic inches, cam specs, compression ratio, etc, doesn't guarantee you will get a "bolt on" no tuning necessary carb, or a carb that has improperly installed parts.
And a wide open dyno sweep pull, is not the end all to a carb's setup. Maybe for a drag car, but not for a pleasure boat. I've seen many friends burn down engines in their boats that were "good" on the dyno.
TAstevens problem for example. Sure, it was lean on the dyno, his power valve jets were plugged. So not enough fuel at wide open throttle on dyno. What about at cruise speed when the engines are in the boat? And the power valve is shut? That scenerio matters just as well, and is a setup/tuning of the main metering circuit, not the power enrichment part of things. Heck, most drag cars dont even use powervalves, and they just block them off anyway and up the main jet size. There is more to setting up a carb, than just whether its rich or lean at wide open throttle. Engines can and do melt down at 3500rpm in boats too.
This is why I am a big advocate of running a wideband on the water. It lets you tune the carb for all areas of operation. Wide open, slow cruise, fast cruise, idle, etc. If you have a carb that doesnt allow you to change out idle feed restrictors, power valve restrictors, air bleeds, emulsion bleeds, then you're only options are changing main jets, or send carb's back to the guy that built them, for mods. I personally, don't have time to pull my carbs off, or friends carbs off, 7 times during a summer to keep sending them back and forth ups, or dropping them off at shops in a quest for a good tune. I'd rather bring a box of carb stuff, spend a day on the water doing some tuning, and call it a day.
I have zero interest in quick fuel carbs. Other than I think they are a good product, with good features, at a good price. Which I have seen perform very well out of the box, with minor adjustments needed. I believe it is a total of 13 quick fuels I have seen in operation out of the box, and all 13 worked great. Im certainly not ignorant enough to think they cant make a mistake during assembly. It probably is a good practice, to remove a few screws and pull the bowls off a new carb, and give them a once over, and verify things are what they should be in there.
And I can tell you from actual experience, just because you send a carb "specialty" shop, you cubic inches, cam specs, compression ratio, etc, doesn't guarantee you will get a "bolt on" no tuning necessary carb, or a carb that has improperly installed parts.
And a wide open dyno sweep pull, is not the end all to a carb's setup. Maybe for a drag car, but not for a pleasure boat. I've seen many friends burn down engines in their boats that were "good" on the dyno.
TAstevens problem for example. Sure, it was lean on the dyno, his power valve jets were plugged. So not enough fuel at wide open throttle on dyno. What about at cruise speed when the engines are in the boat? And the power valve is shut? That scenerio matters just as well, and is a setup/tuning of the main metering circuit, not the power enrichment part of things. Heck, most drag cars dont even use powervalves, and they just block them off anyway and up the main jet size. There is more to setting up a carb, than just whether its rich or lean at wide open throttle. Engines can and do melt down at 3500rpm in boats too.
This is why I am a big advocate of running a wideband on the water. It lets you tune the carb for all areas of operation. Wide open, slow cruise, fast cruise, idle, etc. If you have a carb that doesnt allow you to change out idle feed restrictors, power valve restrictors, air bleeds, emulsion bleeds, then you're only options are changing main jets, or send carb's back to the guy that built them, for mods. I personally, don't have time to pull my carbs off, or friends carbs off, 7 times during a summer to keep sending them back and forth ups, or dropping them off at shops in a quest for a good tune. I'd rather bring a box of carb stuff, spend a day on the water doing some tuning, and call it a day.
I have zero interest in quick fuel carbs. Other than I think they are a good product, with good features, at a good price. Which I have seen perform very well out of the box, with minor adjustments needed. I believe it is a total of 13 quick fuels I have seen in operation out of the box, and all 13 worked great. Im certainly not ignorant enough to think they cant make a mistake during assembly. It probably is a good practice, to remove a few screws and pull the bowls off a new carb, and give them a once over, and verify things are what they should be in there.
06-13-2015 | 08:51 AM
#396
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From: yorkville,il
and if a person sends his carb to one of the custom carb shops and feels that when he gets it back it will be ready to bolt it on and run it with no adjustments he is wrong.IT WILL STILL NEED SOME ADJUSTING.
06-13-2015 | 08:56 AM
#397
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From: chicago
We got the carbs on Thursday, unpacked them, and to our surprise, even after both of my motor builders had personally talked to him about the carb config, he sent them with non adjustable air bleeds... So that was the first issue. The second issue was when we had spoken with him and was talking about linkage setup, he said 1:1, the carbs came progressive... So that was another contradiction we tried to address. The floats were also the brass style.. ehhh, as long as they work, right... I guess when they talked to him and started asking questions about why is this done this way, cause when we spoke, you told us it would be a different way. His response was cause he is the God of carbs, don't mess with them, they are perfect... So they went back and forth a little on the setup and questioned a few things, and was told do not mess with the float levels at all.... Carbs came with 83 Pri jets and 89 Secondary jets. The build sheet wasn't in with the carbs, so we don't know what the air bleeds were, but they were pretty small. 4 corners were larger, the 4 inners were tiny, again, not adjustable, unless you wanna drill holes out on the water... Not ideal at all... Never the less, 30cc primary pumps with 50cc secondary's.... was told they should idle 1200rpm out of the box...
Got to the river Friday afternoon, and started tuning... Got the idle down loping between 650-950 +/-, started tuning the lope out, which it did, but then started stumbling in gear. tried raising the idle a tad, but still would stumble in gear and was very hard to manage.
Decided to go out and see how it ran.. Boat ran pretty good, cruised around on the primaries up to about 45-4800 before you started getting into the secondary's. The transition from primary to secondary was not as snappy, and if you tried throttling it to quickly it would backfire, so you have to ease into the secondary's.
I had 1 of my motor builders with me, so he is coming up with a list of stuff that needs to be addressed. The carbs are super sensitive on idle and will start but almost every time when you try and catch it after it start it stumbles and dies. Then you try and restart, and you have to roll through the gas peddle and hold it open for a couple seconds before it will catch and fire again.
The idle was still temperamental with the lope tuned out, so we tuned the lope back in, and it does just fine, will idle around in gear, and isn't as temperamental in neutral either... Lopes between 800-1100...
Got to the river Friday afternoon, and started tuning... Got the idle down loping between 650-950 +/-, started tuning the lope out, which it did, but then started stumbling in gear. tried raising the idle a tad, but still would stumble in gear and was very hard to manage.
Decided to go out and see how it ran.. Boat ran pretty good, cruised around on the primaries up to about 45-4800 before you started getting into the secondary's. The transition from primary to secondary was not as snappy, and if you tried throttling it to quickly it would backfire, so you have to ease into the secondary's.
I had 1 of my motor builders with me, so he is coming up with a list of stuff that needs to be addressed. The carbs are super sensitive on idle and will start but almost every time when you try and catch it after it start it stumbles and dies. Then you try and restart, and you have to roll through the gas peddle and hold it open for a couple seconds before it will catch and fire again.
The idle was still temperamental with the lope tuned out, so we tuned the lope back in, and it does just fine, will idle around in gear, and isn't as temperamental in neutral either... Lopes between 800-1100...
06-13-2015 | 09:12 AM
#398
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From: On A Dirt Floor
I'm at work because an OE Ford power steering line I was putting in yesterday didn't have the threaded end pressed in all the way. Whore of a line to replace. Left at 9:30 last night and in early today.
People have no freakin idea how bad the screw ups are - more so from aftermarket, but still some from OE.
Doing re-repairs on your own time suks enough, try when it's shop time and that means other vehicles get put on hold and your employees are gonna make extra OT.
And then explain to your family why you don't come home until they are in bed and you lost $$$ at the same time.
Rant over - kind of - but everyone would be in for a rude awakening if they replaced parts everyday !
Edit in: don't forget my story the other day of a new GM longblock where one cylinder head did not have holes for the spark plugs. Solid cast iron there. F Me !
People have no freakin idea how bad the screw ups are - more so from aftermarket, but still some from OE.
Doing re-repairs on your own time suks enough, try when it's shop time and that means other vehicles get put on hold and your employees are gonna make extra OT.
And then explain to your family why you don't come home until they are in bed and you lost $$$ at the same time.
Rant over - kind of - but everyone would be in for a rude awakening if they replaced parts everyday !
Edit in: don't forget my story the other day of a new GM longblock where one cylinder head did not have holes for the spark plugs. Solid cast iron there. F Me !
Last edited by SB; 06-13-2015 at 09:16 AM.
06-13-2015 | 09:14 AM
#399
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Posts: 11,332
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From: chicago
more from this oso friend on that custom carb deal....
Well... Where to start... We got an Innovate AFR... My motor builder and buddy came up Saturday and we were off to the lake for a test and tune... We started off by pulling both carbs and checking since he didn't have a chance to do that on first go... 1 carb was fine, the 2nd was out if sync on the butterfly's... So that got fixed.. The set screw was so loose it didn't have any holding power... Go figure... Fixed and loctited that... they promised to have is the 50cc accel pumps and air bleeds by Friday... Yah, didn't come... Showed up today... Go figure... Apparently my engine builder and buddy *****ed at his so much all he could do was say he was god and was right and he has a boat dock and he knows what he is doing and 99% of his carbs are spot on... Go figure... Pissed to say the least... Bolted the 50cc on and according to them the reason they dont use 50cc is because the arms won't clear... I guess if you are mounting directly to the blower they might not, but we have 1" spacers to run carb screens. Not to mention the throttle linkage bottom if we didn't have the spacers wouldn't rotate cause all that extra linkage stuff below where the the throttle arm connects would have to be cut off to even rotate around... Non the less, the 50cc were fine... Got them all taken care of and bolted on and onto the lake we went...
First AFR reading at 3100-3500 rpm were like 13.1/13.2 then tapper to 12.0, which according to them was the target. He also wanted 7psi fuel pressure... It held the 12.0 pretty much till 5000 rpm and then it went fat.. Shot to 10.1... Then quickly tapered off to 12.1-12.3 at 5500..
First AFR reading at 3100-3500 rpm were like 13.1/13.2 then tapper to 12.0, which according to them was the target. He also wanted 7psi fuel pressure... It held the 12.0 pretty much till 5000 rpm and then it went fat.. Shot to 10.1... Then quickly tapered off to 12.1-12.3 at 5500..
06-13-2015 | 09:22 AM
#400
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Posts: 11,332
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From: chicago
This way a guy who spent 1295 per carb for a 4150 style. For a twin engine roots blower guy, thats $5180.00 for 4 carbs from the boutique, or if he went with the QFT's, he would have been around 3200.00 for four 4150 actual boost referenced blower specific carbs with billet hardware. Not some "externally boost referenced" snake oil bs. Sorry, I'd rather not spend an extra 2k dollars, get cast bodied crap that has no billet hardware, no screw in bleeds or restrictors, and still have to play carb tuner to fix their fukups, and then listen to how "they are god" when it comes to carburetors.
