Impulsive 3.8 swap.

b4black

Well-Known Member
That oil mod is interesting. I'm dealing with that now. I bought a "freshened up" 4.1. It had a roller cam installed and it's not getting oil the driver's side. I'm trying to get the pipe plugs out the back so I connect the two. Of course they are square and not hex. The squares are a sloppy fit with a ¼" drive.

Good deal on the motor being better than you thought. :)
 

WarWagon

Caustic Cacophony
Really nice adjustable push rods in this engine, finally got to look under the valve covers while doing gaskets on those.
It has '78-'82 2bbl heads on it 098 castings.
 

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WarWagon

Caustic Cacophony
This car is my daily driver most of the time so I've done what's necessary to keep it leak free and enjoyable. I believe I'm going to take the Isuzu to Keystone Raceway park for this Wednesday's test and tune.
Get a baseline in a manual trans car, this uses an old Borg Warner T50 5 speeds trans. It has a "dog leg" 1-2 shift pattern so I don't think I can be real quick with it but it's relatively light around 2800lbs so it might surprise me. I have no idea what the rear gears are yet and it's an open diff so I better learn this car launch quick.
 

WarWagon

Caustic Cacophony
Work is very slow today so off came the muffler/Y/H pipe for repairs and CAT deletes. If a machine has open headers you know I'm getting a video!
 

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WarWagon

Caustic Cacophony
Well my daily driver Buick powered Isuzu has developed a miss, Not great for my current project/work situation. I believe the Kenne-Bell 1XB camshaft is wearing out.
Other than the distributor itself I replaced the entire ignition system and swapped in two new fuel filters with no change.
Verified fuel pressure I have 7psi to the carburetor on a return style system.
#5 spark plug gets black while the others remain normal running color.
150psi cranking compression on #5 with warmed engine.
I added a video of a vacuum gauge reading. The engine has a strong vacuum but is not solid. So that info is leading me to the camshaft.
 

WarWagon

Caustic Cacophony
Mr, Ed Kimberly EK02 sent me a camshaft in 2019 that will be the replacement for the 1XB cam if indeed that is the culprit of the engine miss.
I'll update as get on this project but my other daily driver '65 Corvair is getting the time first.
 

ek02

Well-Known Member
Hopefully the cam is not so worn that it got metal all through the engine. I had a KB cam round off a lobe when they took the ZDDP out of Castrol oil. I have used Brad Penn ever since. I just replaced it, changed the oil and filter and ran it with no problem. It had just started to go. Maybe pull the pan and see how much metal is in it.
 

WarWagon

Caustic Cacophony
Hi Ed, I haven't seen any metal in the oil as of yet and I'll be cutting open the oil filter to inspect. Just guessing at the problem with the tools I have available. The valve train is pretty quiet right now and I know this engine has adjustable pushrods. One or two of them could be out of adjustment, who knows. I'll see what's under the valve cover when I get in there.
 

WarWagon

Caustic Cacophony
Update: I'm inside his engine swapping out the cam/lifters, Lost #3 intake lobe and the face of that matching lifter. I did not find any other wear or major issues, but someone did install the thrust button spring backwards into the camshaft and the button seized to the cover so the cam was spinning on the spring instead.
I almost broke the block and camshaft by missing one lifter in the bore, oops.
Everything is OK I got lucky and just broke a lifter in half trying to pull cam out.
I added a pic of the worn Kenne-bell cam/lifter.
I'll clean up some parts and get this back together.
 

WarWagon

Caustic Cacophony
Finished up the cam swap and this engine may have some clearance issues.
Engine has great oil pressure and runs but it has some valve train noise that was not present with the old cam.
This has tall port '78-'82
1262098 casting heads that have work done on them but I don't know exactly how much "aluminum filled exhaust crossover, small port blend, stock runners" They have never been off since I have owned this and I have never removed a valve spring to verify if the exhaust guides were shortened as of yet.
The camshaft I just took out was a flat tappet Kenne-Bell 1XB. It has .456 lift at valve both In&Ex, that cam was quiet and performed well.
The camshaft I just installed has lift @ valves .472 In .496 Ex
Not sure if what I might be hearing is the retainers hitting the exhaust guides.
I've only ran engine enough to break in the cam and set ignition timing and take a quick test trip at this point.
Seems good but it lost a little power down low with this cam.
 

WarWagon

Caustic Cacophony
This is the biggest cam I've ever put in one of my Buick 6's, this noise is new to me.
Before in a 140 block with stock heads
I've installed an Edelbrock cam 204/214 .448In .472Ex
The KB cam I removed was:
206/206 .456In .456 Ex
The new cam: 214/224 .472In .496Ex
 

ek02

Well-Known Member
Have the guides been cut for seals? I would check that first. The new cam only has .040 more lift on the exhaust and .016 on the intake. The guides would have had to be cut to run the old cam. Any cam over .420 lift wont work without cutting the guides. 84-87 heads did not require cutting the guides with your old cam, but the new one may need it done. The cam you took out was pretty mild with a 114 degree LSA. It would be normal to loose some bottom end. I put a 428 Cobra Jet cam in my 390 Fairlane years ago and the bottom end power loss was very apparent. Does it sound like lifter noise? I had the retainer clearance issue once and I ground some material off the bottom of the exhaust retainers. No more than .020 to get the needed clearance.
 

WarWagon

Caustic Cacophony
Thanks for posting Ed. I put a vacuum gauge on this evening and pulling 15" but the needle is jumping around, so something is going on, didn't sound like missing but that is also loosing some bottom end.
I'll get back under the valve covers and take another look around the valve springs probably pull one cylinders springs looking for guide cutting or seals.
If I have to pull the heads I have an opportunity to bump the compression ratio more, each bank has a copper gasket followed by a composite on top.
 

ek02

Well-Known Member
My 4.1 pulls 15" of vacuum with the Comp roller KB Mk2R specs. Sounds like you may have a tight valve causing the fluctuation?
 

WarWagon

Caustic Cacophony
Possibly that or a stuck lifter Ed. Perhaps this weekend I can get some work done on it and find what's causing the problem.
 

WarWagon

Caustic Cacophony
Valve seals on intake guides, exhaust guides are cut and have no seals.
I wiggled every rocker arm while everything was still tight. Almost every exhaust rocker was loose the clearance opened up a lot #5 was worst .044 #3 was .021
I pulled the adjustable pushrods out and compared them to stockers, they are setup the same length as stock.
So with that info this engine just ate another camshaft or lifters or both.
 

ek02

Well-Known Member
I hope the new cam isn't hurt. No seals on the cut exhaust guides should make it smoke at idle if they are cut very much. I wonder why only the exhaust valves were loose? You may want to adjust the valves and check the lift at the rockers before tearing into it. If you used moly lube and some break in additive in the oil the cam should be ok.
 

WarWagon

Caustic Cacophony
I used moly fortified EP lube on cam/lifters, Fresh 20w50 oil with STP zddp additive.
I've never had a flat cam/lifter fail on me that I broke in, until perhaps this one.
Intake will come off I want to put eyes on the cam lobes and lifters but it won't be quick. I'll have to put this on the side for a bit.
 

WarWagon

Caustic Cacophony
Have not gotten the intake manifold off yet to verify the new cam also went bad. I believe I have sourced another off the shelf replacement camshaft, this one will be from Lunati. Staying with flat tappet cam this is: 119/227 @.050 484/.505 lift at valve
112 LSA 108 ICL
 

ek02

Well-Known Member
I am wondering if the retainers on the exhaust valves were hitting the guides. It may have put a lot of pressure on the cam lobes since your exhaust valves were all loose and you said there was a strange noise while running. You would think it would bend the push rods before flattening the cam but you have aftermarket adjustable push rods. If you use the Lunati be sure to check the retainer clearance since the lift on the exhaust valve is higher than the one in the engine now.
 
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