Something isn't right..

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j par

j par

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So I have a customer with a 72 Dart I talked him through building a Dana 60 and he has 456 gears. He had a 904 rebuilt with a new torque converter.. not sure of the stall but it's not super significant but not stock... He had the bottom end done at a machine shop 30 over, Pistons maybe .010 below deck.. we put a 8553 felpro head gasket and some $400 eBay Edelbrock open chamber heads.. a pretty nice Edelbrock air gap intake and some cheap Summit headers. A 7al with a brand new MSD no vacuum advance distributor with the light silver and blue spring..
We broke the engine in but it was very lean and lean popping anytime we took it over 2500 RPMs.. I was obviously a old boat motor carburetor. It was a Holley double pumper. He wanted a new carburetor anyways so he bought a brand new Holley brawler... It ran super lean and this is with a brand new stock fuel pump..
Okay starts perfect idles fine (ruff with a long duration cam but fine..) turns right off and revs very responsibly in park..
Put it in gear and runs fine again a little rough but that's mostly due to the cam..
Oh yeah hydraulic lifters and stock rockers we do have the stuff to upgrade but not yet.. we've also tried changing power valves as it has about 12 to 13 lb of vacuum and the factory power valve was a 4.5 and we put a 6.5 in... Plenty of adjusting got it a lot richer and it helped quite a bit but the big problem is once he gets going or starts giving it serious gas it chugs and pops and chugs and pops...
It almost felt like it was running out of gas.. I went home and grabbed an electric fuel pump that I have the same one that I use for my dual quads and it brought the fuel pressure up and steady..
Same problem..
Thank you for any help..
 
If it’s lean it will pop one time out the carb when you mash it. If it’s rich it will pop and bang repeatedly out the exhaust. What do the plugs look like? And what’s the timing curve like?
 
Had a buddy with those same symptoms ! Also on a new build ! Cam went flat ! Pulled the motor back out ! He tore it all down again to get all the metal out of it !
 
Have ya checked the valve trian to see if there’s a lose rocker? That the first indication of a cam going south. If yes, I’d pull the intake and take a look at the cam / lifters. Check to see it the lifters are spinning not stuck. Yeah it kinda sucks to do it but it’s the best way to find out. Did you cut open the oil filter and check the oil after break in? A friend had a cam go south in about an hour after break in last summer.... the cam ate the face off an EDM lifter...
 
Scody21 said:
Have ya checked the valve trian to see if there’s a lose rocker? That the first indication of a cam going south. If yes, I’d pull the intake and take a look at the cam / lifters. Check to see it the lifters are spinning not stuck. Yeah it kinda sucks to do it but it’s the best way to find out. Did you cut open the oil filter and check the oil after break in? A friend had a cam go south in about an hour after break in last summer.... the cam ate the face off an EDM lifter...
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Been seeing a lot of folks having new cams/lifters go bad very quickly. UTG talks about current quality control across the board is in the toilet. Local shop I work with told me yesterday that they built a flat tappet cam engine for a customer and the new lifters failed and ruined the cam.
 
TT5.9mag said:
If it’s lean it will pop one time out the carb when you mash it. If it’s rich it will pop and bang repeatedly out the exhaust. What do the plugs look like? And what’s the timing curve like?
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After the initial break in with the first carb I checked the plugs and they were very clean.. it's more of the repeated pop like rich and now unlike the break and run we're getting a rich smell and a Little smoke.. the brand new MSD distributor had the factory heavy silver Springs and we suspected something like that because under throttle is when it's happening and I suggested we did the light silver spring and a Blue spring like I have in my car for a faster ramp up.. unfortunately the timing is just set my ear as my timing light seems to work for my 6al but his 7al has it jumping all over the place.. I've tried a couple different positions and that hasn't worked but I do have it in a spot that starts and stops and after doing this for a long time by ear feels quite good...
318willrun said:
you didn't lose a lobe, did u ??
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Yes I was starting to feel that and especially I got feeling was from the passenger side. I took the valve cover off and had him turn it over several times and felt the rockers and they all seem to stay tight as it has hydraulic lifters but that's as far as I went... Again I'm there to assist my customers and give them my best advice not tell them how to run the show and when they want to go a different way I just follow what they want...

Scody21 said:
Have ya checked the valve trian to see if there’s a lose rocker? That the first indication of a cam going south. If yes, I’d pull the intake and take a look at the cam / lifters. Check to see it the lifters are spinning not stuck. Yeah it kinda sucks to do it but it’s the best way to find out. Did you cut open the oil filter and check the oil after break in? A friend had a cam go south in about an hour after break in last summer.... the cam ate the face off an EDM lifter...
Click to expand...
Yes I'm not afraid to get into the motor or pull the intake that's not a problem but we're trying to exhaust the simpler avenues first just tuning.. again I'm there to help my customers do what they want and not tell them what to do... He did change the oil and he did cut the oil filter open and said he seen nothing....

Ricks70Duster340 said:
Been seeing a lot of folks having new cams/lifters go bad very quickly. UTG talks about current quality control across the board is in the toilet. Local shop I work with told me yesterday that they built a flat tappet cam engine for a customer and the new lifters failed and ruined the cam.
Click to expand...
I help this customer between 4 and 5 years ago get his Dana set up and get this project started... He kind of dropped the ball for 4 years so all of the stuff has been sitting for 4 years.. the built bottom end was wrapped in cellophane from the machine shop. The lifters were still in their box. The transmission was still on the floor where I left it 4 years ago... I'm there to help my customers if they want help I don't bang on their doors for work... It's quite funny how I got back in touch with this guy as he put an ad in the parts section looking for help with his car and had a picture of it. I go hey that's so and so and gave him a call.. when I told him who I was he was extremely excited that I called and had said he lost my phone number and wants to get started back on his project again...

Mtrhead said:
Cam lobe wiped out my guess also...
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Of course it was one of the first things I thought as well.. I did check the passenger side like I said and I will check the driver side the next time I see him. What's taking us down the avenue of the carburetor is again when we broke it in it was doing okay except for when you started to rev it up a little bit too much. Which was kind of leaving the idea in my head there may be a bent push rod... (Hopeful I know..) when we put the new carburetor on there that seemed to solve some of that and adjusting it solve quite a bit of it so that was what was leading us down the road of maybe it's just more adjustment on this carburetor. But again now we have it to where it seems perfect then we take off to go drive it and all is not happy...
 
Ricks70Duster340 said:
Been seeing a lot of folks having new cams/lifters go bad very quickly. UTG talks about current quality control across the board is in the toilet. Local shop I work with told me yesterday that they built a flat tappet cam engine for a customer and the new lifters failed and ruined the cam.
Click to expand...

Makes me wonder if people are not removing the inner springs or using a lighter spring / pressure for brake in... I know for my 2 year old Comp 285XL (that’s not a 4 speed friendly cam) the guy I had build it handed me a box with the inner springs when I picked up the motor. The cam my buddy lost last summer, he was being lazy and did not want to pull the springs....
 
Scody21 said:
Makes me wonder if people are not removing the inner springs or using a lighter spring / pressure for brake in... I know for my 2 year old Comp 285XL (that’s not a 4 speed friendly cam) the guy I had build it handed me a box with the inner springs when I picked up the motor. The cam my buddy lost last summer, he was being lazy and did not want to pull the springs....
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I seem to have busted that mith with both of the cams that I broke-in in my own motor... Or as you may say I got lucky.. I'm highly suspect of these four or five year old $400 eBay heads with a sticky valve or something... Again these are my customers I can only lead them to water I can't make them drink..
Not this customer in particular but other customers I have I watch them spend three times as much money to save or I should say try and save money....
 
What coil is he using? My MSD 8222 expoy filled high vibration blaster took a **** over the weekend. Thinking about the last time I drove the car 3 months ago. It was not happy. Would pop and sputter in deceleration. Went to start it Sunday and it would only crank, changed the coil and she’s running like a champ again...
 
I don’t trust timing by ear except for maybe idle. What advance stop bushing is in the MSD distributor? Likely you have too much mechanical advance if you timed it by ear at idle and it has anything but the black bushing. And even then it might be too much if you’re above 18 or so initial. I would do two things before anything else. SET the timing where it needs to be. Something like 18-34. Then leave it there. Next I would verify rotor phasing and if it’s off correct it. MSD makes an adjustable rotor for that. It works awesome. Then, and only then work on the carb tune.
 
Scody21 said:
What coil is he using? My MSD 8222 expoy filled high vibration blaster took a **** over the weekend. Thinking about the last time I drove the car 3 months ago. It was not happy. Would pop and sputter in deceleration. Went to start it Sunday and it would only crank, changed the coil and she’s running like a champ again...
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Yes some brand new coil that has to be paired with the 7al...
Again it really makes me wonder why someone would sell a set of Edelbrock heads for $400... Think they may have had problems with them?...
 
TT5.9mag said:
I don’t trust timing by ear except for maybe idle. What advance stop bushing is in the MSD distributor? Likely you have too much mechanical advance if you timed it by ear at idle and it has anything but the black bushing. And even then it might be too much if you’re above 18 or so initial. I would do two things before anything else. SET the timing where it needs to be. Something like 18-34. Then leave it there. Next I would verify rotor phasing and if it’s off correct it. MSD makes an adjustable rotor for that. It works awesome. Then, and only then work on the carb tune.
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I totally agree with you.. again if this was my own stuff....
I don't like tuning stuff by ear either and if it was my car I would buy the MSD timing light so I can verify things... I 100% understand and have discussed with my customer the timing needs to be somewhere between 18 to 22 initial and around 34 and possibly up to 36 All in...
It still has the original blue stop in it and that's probably part of the problem as well..
Lord knows I like this customer like I like all my customers but again I can't do anything but make suggestions. I watch them spend big money on stuff that their favorite racer on street outlaws has but not the stuff to tune it...
I brought my timing light I brought my vacuum gauge I brought my heat gun I brought anything he needs gave him an alternator.. brought the proper funnel so he could fill his transmission without pouring it all over the car. He currently has my spare electric fuel pump...
He has aspirations of drag racing this car and an entire MSD setup.. will he buy a timing light? Time will only tell...
One thing for sure when we rev it past three grand at a standstill it acts fine... Not pinging or knocking back or popping..
 
Honestly it seems pretty close...
But you go drive it and not so much...
My gut feeling is it's just one "aha" moment away from running correctly...
He'll be at the Mopar Nationals this Sunday and I'm going to talk to him about buying the correct timing light as he will need one regardless. And with that said I'm going to bring a different carburetor and I want to check the driver side rockers...
 
Valve guides too tight, valves hanging open?
Lots of knowledgeable people recommending having even brand new heads looked at, quality control not what it should be.
 
Had a similar issues with a couple chevys lately.
18436572.
It happens.
Argued with my buddy, didnt want to recheck.
7/2 swapped.
 
33IMP said:
Valve guides too tight, valves hanging open?
Lots of knowledgeable people recommending having even brand new heads looked at, quality control not what it should be.
Click to expand...
Yes this is a suspicion of mine... The Speedmaster heads I got a couple years ago I had looked at and they said the only thing was the lubricant was dried and they just lubricated the valve stems and put them back together and they were fine... Again he bought these Edelbrock heads complete from eBay probably more than 4 years ago and they sat out and in his unheated garage for an unknown amount of time and we just kind of cleaned them up a tick and slap them on...
 
Tooljunkie said:
Had a similar issues with a couple chevys lately.
18436572.
It happens.
Argued with my buddy, didnt want to recheck.
7/2 swapped.
Click to expand...
Yes had it happen with the 5.7 before...
We've been around them a couple times...
I can tell you when the 5/7 was crossed I knew it wasn't running right in the driveway when I drive it up it would pop or get it going faster it would pop..
But I can start this car and it will idle and goose the gas and it has instant response and Revit to pass three grand and hold it and all is good...
Go to drive it and it goes into gear and holds its idle no problem back side of the driveway no problem gives it gas no problem starts giving it more gas and putting a heavy load on it and then it commits to popping and acting as if it's running out of gas... Hence the electric field pump and that didn't work...
Again with my customers a lot of times I just work once a week on their day off or something and we have an unlimited amount of time that they pay for. We try to go down the quick avenues without having to tear the engine apart. I'm not afraid to of course but are they willing to spend the money...
 
Of course when he said he was going to buy a new carburetor after the initial break in I tried to give my best case for getting an Edelbrock or a street demon...
This was going to make it simple...
I 100% agree that a holly style carburetor is going to be much more tunable and more suited for drag racing and really for a lot of people they work great I'm not trying to start a holly versus Edelbrock for the millionth time thread... But were this guys at and his tuning ability and the fact that he's never even pulled a car up to the Christmas tree in his life starting out with an inexpensive carburetor that is much more user friendly AKA simple would get him up to the starting line and down the track and get all the other things he needs to get figured out and then if he needed to go one or two or three tenths faster go ahead and buy that street brawler is what he bought and start learning to tune your carburetor after you get everything else sorted out.
I could start at the back of the car and work my way to the front of all the things that are wrong before this car ever really sees any time at the track... I just wish he would have made it much simpler...
 
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