Built 360 Having a Tantrum

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Dodge72

Odd one out
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Olympia, WA
Hey y'all. I'm posting on behalf of my boyfriend's 73 Duster that he's been having issues with every time he tries to drive it and we need some advice. Some background: He's got a 360 with flat top pistons (not sure what brand), 340 X-Heads with 2.02 intake valves and possibly more work done to them (haven't looked yet), unknown brand of headers, 2 1/2" dual exhaust, and a single-plane intake with a 750 CFM Edelbrock. Crane Cam adjustable gold rockers. I'd have to find cam specs but it's a pretty aggressive street/strip hydraulic flat tappet cam from Comp.

Edit : His cam is a Comp Xtreme Energy, # XE284H..507/.510 lift @ 240/246 @ 50


Most recently he had switched over his single plane Holley Strip Dominator for a more streetable dual-plane Edelbrock RPM (non-air gap). After the install, he heard what sounded like a misfire and using a infrared temp gauge, it read that #5 was cooler than the rest and not firing. Found that his plug wire was starting to crack from heat. Patched it up and started it again. He got it to warm up, and tried to take it out for a short drive. He got to the stop sign and hit the gas, only to get a huge cloud of white smoke from the driver's side exhaust. Trip over! Turned around and limped it home. Now what has been a standing issue is that #1 is EXTREMELY noisy. Almost like a solid lifter that doesn't have any oil. Super noisy when cold, does quiet some when warm but super obvious when he hits the gas. He has tried to adjust the screw on it some (all of them are set to 0 lash according to Comp), but it does not help. I say this because when he got it home we did a compression test, dry. Results:


Driver's Side

#1 = 105 psi
#3 = 155 psi
#5 = 110 psi
#7 = 145 psi

The passenger's side evened out, all at 125-130 psi. BTW, this side is completely silent, and does not smoke. We tried the wet compression test on #1 and it only bumped it 5 psi to 110. So he ended up taking the head off. Head gasket looked okay, no obvious signs of failure or breakage. (Using blue Fel-Pro head gaskets). Pistons looked okay, as did the valves. Exhaust gasket says that the headers leak, especially on #1. We are gonna do a little light test to see if the valves are sealing well, then take them out to look for straightness. I want to say it may be a bad hydraulic lifter not pumping up, or could it even be a bad exhaust leak causing the noise? A little far fetched but perhaps since this was previously a drag-only car, the heads had been milled and the original intake was milled too, allowing for ports to align? How does one check for that? I will do a cc check on the head as well when I have time, it should tell if it's been milled. Sorry for the essay, I just wanted to get all the info out of there and hopefully get some advice or some pointers on what to look for. Thank you!
 
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And here's the picture for the exhaust gasket on the driver's side:

20190528_200847.jpg
 
And here's the picture for the exhaust gasket on the driver's side:

View attachment 1715341960


That's not a header gasket. You either have pretty low compression ratio or a huge cam and I doubt the cam is very big.

While you are that far into it, you might as well check the cam timing. It may be retarded so far it's killing cranking compression.

I'd have left the SD on it and fixed the other issues.
 
I will stick my neck out a little and do the thing you aren't supposed to do and assume you are a female. With that in mind, you have quite a mechanical vocabulary, very unusual/refreshing. Since it sounds like this engine was extensively modified before your boyfriend got it, any diagnoses are going to be just guesses. Sounds harsh but I would pull it out and find out what I've got with a tear down and thorough inspection. Who knows what you will find??? Could be anything, could be multiple things. or you could just throw money at it and see what happens. That is the "typical" type of diagnosing a problem that I see most often.
 
Roll the pushrods on the table from #1 and see if they are bent.

Next step adjustable rockers might not be set right, have to run through them again and double check they are set correct, especially # 1 when you get it back together. They can be tricky to get just right if not real farmiliar on how to do it.

Hope this helps, good write up on all the info on the engine.
 
White smoke is usually water (head gasket going bye bye)...did it milk the oil, or are you missing some water?
 
Thank you guys! I did not raise that was an incorrect exhaust gasket, we'll get a correct set. And yes , more than likely he will switch back to the single plane just to eliminate that possibility.

As far as cam timing, I want to say he lined it up at 0 @tdc. Probably not the best (and I don't know if the cam has ground in advance either) but we were both not confident in degreeing the cam. Yes, be did get this car with this engine already in it, so he was working with what he had. Before all this he did take the engine out and did a refresh on it: new gaskets, bearings, new timing chain, new cam, lifters, pushrods, the like. He's probably only driven it a few hundred miles at this point. He didn't take pistons out so no new rings. Before this, it drove great besides the noise at #1. I want to say it's gotten worse, but it may be just that I noticed it more now. We can check that cam timing again though, wouldn't be much now. Pushrods looked fine but those will get checked just in case.

And why yes, I am a girl lol. Thanks! I got my own A Body so you definitely need to know a few things first. :D Sure is nice to have somebody who loves old Mopars as much as you do.


EDIT: White smoke is usually coolant, which is partially why we took the head off to inspect the head gasket. The coolant was clean, the oil looks fine.

EDIT 2: Got the cam specs if it matters, edited my original post. Comp #XE284H.
 
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Coolant could have been from the the intake swap and seeped in from that intake gasket.
The original intake was milled to match the milling on the engine.
when the intake sits between the heads, this way the bolt holes and yes ports, line up.
\____/
 
Pictures of head gasket? Piston tops? Does the piston in cylinder 1 look steam cleaned? Could be a crack in the head. Pressure test the cooling passages in the head.
 
Thank you guys! I did not raise that was an incorrect exhaust gasket, we'll get a correct set. And yes , more than likely he will switch back to the single plane just to eliminate that possibility.


As far as cam timing, I want to say he lined it up at 0 @tdc. Probably not the best (and I don't know if the cam has ground in advance either) but we were both not confident in degreeing the cam. Yes, be did get this car with this engine already in it, so he was working with what he had. Before all this he did take the engine out and did a refresh on it: new gaskets, bearings, new timing chain, new cam, lifters, pushrods, the like. He's probably only driven it a few hundred miles at this point. He didn't take pistons out so no new rings. Before this, it drove great besides the noise at #1. I want to say it's gotten worse, but it may be just that I noticed it more now. We can check that cam timing again though, wouldn't be much now. Pushrods looked fine but those will get checked just in case.

And why yes, I am a girl lol. Thanks! I got my own A Body so you definitely need to know a few things first. :D Sure is nice to have somebody who loves old Mopars as much as you do.


EDIT: White smoke is usually coolant, which is partially why we took the head off to inspect the head gasket. The coolant was clean, the oil looks fine.

EDIT 2: Got the cam specs if it matters, edited my original post. Comp #XE284H.

Great, you are really smart about all of this.
Glad you got an A Body, hats off to you . .
 
Don’t worry about the Essay. It’s informative and well written. Most guys should take note!
(hint hint)
The wide and varied psi readings are worrisome.
 
This is one old man's opinion and not criticizing in any way so please don't take it that way.

I think he jumped the gun disassembling it. There was more diagnostic work to be done. You're very vague in your terms talking about valve adjustment. Do either of you know the correct procedure for valve adjustment?

Again, not criticizing, only asking, because I have no way to know what either of your abilities are. Obviously, #1 has an issue. Could be a rocker out of adjustment, bend pushrod, bad lifter, worn lifter and or wiped camshaft lobe.

Before it was torn down, did he watch the rockers to see of all of them were moving the same amount? In other words looking for a wiped cam lobe and or bad lifter? This is some of the diagnostic work I was talking about. There's even more involved such as putting shop air into that cylinder with both valves closed and seeing "where" the air goes. You can diagnose a bad intake, exhaust valve in that manner. This is why I said I think he jumped the gun. Not the end of the world, now you just need different diagnostic procedures.

At this point, I would set the head up level on the combustion chamber side and fill #1 up with rubbing alcohol. CHeck to see if any leaks out into the intake and or exhaust ports. If it does, check the rest. If they do as well, it probably needs a valve job, or has some bad valves and or seats.

You can also roll the pushrods on a level surface and check them for being bent. A bent one will stick out like a sore thumb. Inspect the valve springs closely. Make sure you don't have any broken springs. Also look closely at the valve spring retainers and the top of the valve guides for witness marks. If the retainers are hitting the guides, this can cause binding and bend a pushrod.

These are just some of the things I would check for at this point.

Good luck. If you need some more help, PM me and I will be glad to talk to either or both of yall on the phone if need be.
 
I would second the intake passing coolant. The compression tells me the lifters are set a little tight maybe.
 
This is one old man's opinion and not criticizing in any way so please don't take it that way.

I think he jumped the gun disassembling it. There was more diagnostic work to be done. You're very vague in your terms talking about valve adjustment. Do either of you know the correct procedure for valve adjustment?

Again, not criticizing, only asking, because I have no way to know what either of your abilities are. Obviously, #1 has an issue. Could be a rocker out of adjustment, bend pushrod, bad lifter, worn lifter and or wiped camshaft lobe.

Before it was torn down, did he watch the rockers to see of all of them were moving the same amount? In other words looking for a wiped cam lobe and or bad lifter? This is some of the diagnostic work I was talking about. There's even more involved such as putting shop air into that cylinder with both valves closed and seeing "where" the air goes. You can diagnose a bad intake, exhaust valve in that manner. This is why I said I think he jumped the gun. Not the end of the world, now you just need different diagnostic procedures.

At this point, I would set the head up level on the combustion chamber side and fill #1 up with rubbing alcohol. CHeck to see if any leaks out into the intake and or exhaust ports. If it does, check the rest. If they do as well, it probably needs a valve job, or has some bad valves and or seats.

You can also roll the pushrods on a level surface and check them for being bent. A bent one will stick out like a sore thumb. Inspect the valve springs closely. Make sure you don't have any broken springs. Also look closely at the valve spring retainers and the top of the valve guides for witness marks. If the retainers are hitting the guides, this can cause binding and bend a pushrod.

These are just some of the things I would check for at this point.

Good luck. If you need some more help, PM me and I will be glad to talk to either or both of yall on the phone if need be.
Great advice.with the leakdown test,and rad cap off occasionally you can see the coolant rise in rad or bubbles may appear. Dont always get that lucky but sometimes worth a shot.
 
Don’t worry about the Essay. It’s informative and well written. Most guys should take note!
(hint hint)
The wide and varied psi readings are worrisome.

No kiddin. It's nice to see something other than "something's wrong with my car, it's red".
 
With #1 and #5 compressions being low, I'd suspect the valves are hanging up a bit for some reason and keeping the valves open too much, or the lifters have lost the clips on top, pumped up, and bent the valves. Bent pushrods would be a sign of this last.

#3 and #7 look to have a similar problems pending.... compressions high indicates the intake closing too soon; those are more likely lifters collapsed.
 
The variation in compression is a definite red flag, I agree with Rusty Rat Rod that more diagnostic work is needed, first instinct is stuck or possibly bent or burned valve, or seat. Noise from that cylinder is a solid clue, even a bad lifter or incorrectly adjusted valve, any of these could cause low compression. Also strong possibility that the heads have been milled and the intake swap has created a coolant or vacuum leak. Keep us posted on your progress/findings.
 
The variation in compression is a definite red flag, I agree with Rusty Rat Rod that more diagnostic work is needed, first instinct is stuck or possibly bent or burned valve, or seat. Noise from that cylinder is a solid clue, even a bad lifter or incorrectly adjusted valve, any of these could cause low compression. Also strong possibility that the heads have been milled and the intake swap has created a coolant or vacuum leak. Keep us posted on your progress/findings.
Also a bad lifter or wiiped cam lobe. Keeping an eye on this thread. Good luck to the Lady and her man.
 
The variation in the compression readings doesn't bother me right away. Since he has adjustable rockers "all it could be" is a bad valve adjustment. So, it might not "that bad".
 
I got a bit of an update here. The valves didn't leak any with fluid in the combustion chamber, so that's good. Right now we are trying my redneck cc checker ( graduated syringe and a piece of drilled Lexan) but it keeps trying to leak, so we're working on that. But! I noticed the head had this lovely here,. 010":

20190602_175723.jpg

I'm guessing it was milled then? Would .010" be enough to need to have an intake milled?
 
I got a bit of an update here. The valves didn't leak any with fluid in the combustion chamber, so that's good. Right now we are trying my redneck cc checker ( graduated syringe and a piece of drilled Lexan) but it keeps trying to leak, so we're working on that. But! I noticed the head had this lovely here,. 010":

View attachment 1715344061
I'm guessing it was milled then? Would .010" be enough to need to have an intake milled?

Nope.
 
20190602_184256.jpg
20190602_184244.jpg


And here's a piston at TDC. Comparing it with a straight edge, and the center comes above the deck and the outer edge of the piston is at zero deck.
 
Uhhhh.....what kinda gas does he run in that thing?
 
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