Well, that was disappointing...

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Rettax3
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Well, that was disappointing...

Postby Rettax3 » Tue May 01, 2018 12:27 am

I took a break this afternoon from the DOHC-Z project. I found this on my old Plymouth's engine: :o
400 Cam Bearing1a.jpg

This is not the original 383 Big Block from my car, which is sitting on a stand too. This is a replacement Big Block I bought a couple of years ago to drop into the car while the 383 was being rebuilt (and yes, 'BUILT'). But, it turned out to be a fairly fresh rebuild already, and I liked this engine after I picked it up and found how clean it was (as you can see in the pics, the inside is spotless except for some minor surface-rust in the water passages), so I decided to build it a little first. It is the same block as my 383, but with heavier castings and the biggest slugs Mopar used back then, 90-thousands more than the 383 and even bigger than the famed 440. I bought a new Lunati VooDoo cam for it over the winter, and a gear-drive set to go with it (Mopars are notorious for stretching their chains -they still run fine, but not necessarily ideally). I thought the cam bearings would be new with the rebuild, and was ready to slide in my new cam and lifters. Nope. Looks like water damage to me, I am afraid of what the crank bearings look like. I scoped the cylinders when I bought the engine, and they are great.
Lunati Cam 1a.jpg

Yep, that definitely crimped my plans for the evening... Every time I move forward on this thing, I get set back half a pace. BACK TO THE BERETTA!


1989 SuperCharged 3800 Srs-II (First)Six-Speed GTU
1990 Turbo 3.4 5-Speed T-Type
1990 4.0L 4-Cam 32-Valve V-8 5-Speed Indy GTi (Project)
1990 Stock(!) 3.1 MPFI Auto Indy
1995 LA1/L82 4T60E Z-26
1995 3.4 DOHC Turbo 5-Speed Z-26

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Rettax3
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Re: Well, that was disappointing...

Postby Rettax3 » Tue Jul 24, 2018 4:18 am

I finally snuck off the other day to replace the camshaft bearings in the old Mopar. I had searched a little and gotten the multi-layer babbit bearings I wanted. The gear-drive set I bought is adjustable, the alignment dowel (arrow) has multiple off-center inserts to micro-adjust the cam timing. The Lunati cam I bought has the performance-style three-bolt mount, vs the stock-type single-bolt. Interestingly though, Lunati uses 3/8" bolts, the timing gears were supplied with 5/16" bolts although the holes were big enough for 3/8s. I will have to get a couple more Grade-8 bolts -I could only find one of the right length in my stash... It is getting closer!
400BBM Timing Gears 1b.jpg


1989 SuperCharged 3800 Srs-II (First)Six-Speed GTU
1990 Turbo 3.4 5-Speed T-Type
1990 4.0L 4-Cam 32-Valve V-8 5-Speed Indy GTi (Project)
1990 Stock(!) 3.1 MPFI Auto Indy
1995 LA1/L82 4T60E Z-26
1995 3.4 DOHC Turbo 5-Speed Z-26

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Re: Well, that was disappointing...

Postby GT_Indy » Tue Jul 24, 2018 10:33 am

Looks good to me. lol.
I wonder if straight gears like that is better or more reliable than using a timing chain, or a double roller chain.
Do you think grade 8 is strong enough for that?


96 Beretta Z26 swap
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Rettax3
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Re: Well, that was disappointing...

Postby Rettax3 » Tue Jul 24, 2018 6:38 pm

GT_Indy wrote:Looks good to me. lol.
I wonder if straight gears like that is better or more reliable than using a timing chain, or a double roller chain.
Do you think grade 8 is strong enough for that?

Thanks. Especially with Mopar engines, chains tend to stretch over time, significantly altering actual cam-timing. Vibrations are not good either. The Big Block "B" engines (as opposed to the Big Block "RB" or Raised Block, like the 426 and 440 engines wich have taller decks and longer rods) are rev-happy powerplants, and sloppy chains are just counter-productive. This cam is fairly radical, about the limit for good streetability. With the upgraded valve-springs and the RPMs this engine will see, I don't want 'variable valve timing' or vibrations interfering with reliability or performance. A double-roller chain would be a vast improvement too, but I also like the sound of a noisy gear-set. :wink:

Is Grade 8 strong enough? Well...
On a 3/8" bolt (and this has three of them), Grade 8 is good for over 10,000 pounds of shear force. ARP can do about 400 pounds more -oooo 4%. :roll: Grade 5, which the set was designed for and equipped with, is over 8,000 pounds, but they sent 5/16" bolts which drops the strength to 5750 pounds per bolt. Normally, the stock cam has only one dowel-pin, plus the friction from the center-bolt torquing the timing gear to the face of the cam. This set is nearly press-fit too -it is going nowhere without its' cam... :good:


1989 SuperCharged 3800 Srs-II (First)Six-Speed GTU
1990 Turbo 3.4 5-Speed T-Type
1990 4.0L 4-Cam 32-Valve V-8 5-Speed Indy GTi (Project)
1990 Stock(!) 3.1 MPFI Auto Indy
1995 LA1/L82 4T60E Z-26
1995 3.4 DOHC Turbo 5-Speed Z-26

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Re: Well, that was disappointing...

Postby GT_Indy » Tue Jul 24, 2018 9:50 pm

I guess I'm just used to grade 8. I buy grade 8 bolts nuts, and washers for literally everything. Including exhaust. lol.
I know grade 10 is a thing, but I don't know if it can become brittle and fracture from continued stresses and heat changes. I know some bolts are 1 time use, I found that out when I tried to re-use rocker bolts on my olds 455 engine, they twisted when I was torquing them so I had to buy new ones.

That makes me want to redo my olds 455 with gears but I'd have to look into if they offer it or not. I like the gear noise/whine as well. Gear lash sounds not so much, those bug me a bit.

I wonder if a Quad 4 can be converted to gears. LOL. I think it might improve reliability other than the oil pumps tendencies to fail. Honestly, why do they die so often? I look at the Gen2 and Gen3 v6 oil pumps and they work fine, 300k miles and they still pump, but quad4's? They die after like 20k miles. Mind boggling. Makes me want to buy a spare oil pan gasket and oil pump and keep a simple set of tools on hand for daily driving or trips with my gtz. Jack it up, swap it, keep going. lol.

But that is why I like the older stuff as well, simplicity, reliability. As long as it gets oil changes it will keep going.


96 Beretta Z26 swap
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Rettax3
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Re: Well, that was disappointing...

Postby Rettax3 » Wed Jul 25, 2018 1:24 am

GT_Indy wrote:I guess I'm just used to grade 8. I buy grade 8 bolts nuts, and washers for literally everything. Including exhaust. lol.
I know grade 10 is a thing, but I don't know if it can become brittle and fracture from continued stresses and heat changes. I know some bolts are 1 time use, I found that out when I tried to re-use rocker bolts on my olds 455 engine, they twisted when I was torquing them so I had to buy new ones.

That makes me want to redo my olds 455 with gears but I'd have to look into if they offer it or not. I like the gear noise/whine as well. Gear lash sounds not so much, those bug me a bit.

I wonder if a Quad 4 can be converted to gears. LOL. I think it might improve reliability other than the oil pumps tendencies to fail. Honestly, why do they die so often? I look at the Gen2 and Gen3 v6 oil pumps and they work fine, 300k miles and they still pump, but quad4's? They die after like 20k miles. Mind boggling. Makes me want to buy a spare oil pan gasket and oil pump and keep a simple set of tools on hand for daily driving or trips with my gtz. Jack it up, swap it, keep going. lol.

But that is why I like the older stuff as well, simplicity, reliability. As long as it gets oil changes it will keep going.

:D

Quad oil-pumps are, well, interesting. I've only had one fail, and yes, it caused the death of the crankshaft within about five seconds of pressure-loss, thanks Oldsmobile! Phenolic driven-gear on the pump, presumably used so that if the pump seizes (like mine did) it doesn't destroy the drive-gear on the crank (of course my crank was ruined anyway), and it is also quieter and to a degree self-lubricating. Interesting concept -some old engines actually use a similar phenolic gear for the cam, just to go full-circle. Honestly, my Quad (a L.L.L.L.O. SOHC variant) had something like 180K on it, I doubt the pump had ever been changed, and I know the bearings hadn't been. I had looked them over at about 164k, and they were still serviceable, but showing wear. If that engine had brand-new bearings when the oil-pump failed, maybe they would have survived? Or maybe it would have just ruined new bearings...

Oil pump on a Mopar Big Block? RIGHT ON THE OUTSIDE OF THE ENGINE! In fact, the oil filter screws directly onto it on the front. Piece of cake to swap, could probably do it in five minutes with some practice. :good:
BBM 400 Oil Pump 1b.jpg


Grade 10? I used to know hardware pretty well, I've never heard of a Grade "10". Metric has Class 10.9, closely equivalent to SAE Grade 8 for strength. AN hardware (Aviation) is more consistent in strength and quality, and MS (Mil Spec, used in commercial aviation and military applications) is stronger still.

Very few bolts are truly one-time use, although Torque-To-Yield bolts certainly are (like Quad head-bolts :roll: ). It doesn't mean they are still good after years of punishment though...


1989 SuperCharged 3800 Srs-II (First)Six-Speed GTU
1990 Turbo 3.4 5-Speed T-Type
1990 4.0L 4-Cam 32-Valve V-8 5-Speed Indy GTi (Project)
1990 Stock(!) 3.1 MPFI Auto Indy
1995 LA1/L82 4T60E Z-26
1995 3.4 DOHC Turbo 5-Speed Z-26

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Re: Well, that was disappointing...

Postby GT_Indy » Wed Jul 25, 2018 5:24 pm

Wow that makes it easy to replace on the mopar.

Yah I'm considering adding a oil pressure cut out to my 90 gtz, so if the pressure is lost, it kills the ignition. Only flaw with that plan is if the clutch is engaged, the engine is still going to spin and risk dying from no oil pressure.


96 Beretta Z26 swap
90 Beretta GTZ
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