lifter bores on old BBC

[i82much]

Many of you have commented on my 496 thread about whether to use my 702 heads - thank you.

Related question - I'm thinking I might take my time and try to find some good cores locally - a 454 block and some open chamber oval port or peanut port heads. Could take awhile. My 396 is starting to look like it might have wiped a lobe on the flat tappet that is currently in the block.

One thought I had was to just convert the 396 over to a mild hyd roller now, see how it runs and then decide from there whether to keep looking for another block. But I don't really want to spend the money on a hydraulic roller upgrade if my lifter bores are going to beat up the lifters - I'd just need to buy them again if I wind up building a new engine.

Chances are pretty slim that a 1966 engine block is going to have good lifter bores, no? If they are bad, I probably need to think about either just biting the bullet for a complete engine now, or going back with a cheap flat tappet until I find some good cores locally.

[dannobee]

Bronze sleeves at the lifter bores does two things. The angles get "fixed" and the bronze wears better than the cast iron.

[brandonu]

I doubt any seasoned engine block would have perfect bore locations/angles/clearance. The only way to ensure them being correct is to locate with a fixture and either bore to a .903 or sleeve. I don't think I would encourage my customers to spend the extra money to do so in this application unless they had future plans, had to use that specific block, or just wanted it to as perfect as possible and didn't mind spending the money. Barring excessive clearance or damage, the stock .842's should serve your intended usage just fine.

One thing to remember here, 65-66 BBC's require a grooved rear cam journal for top end oiling.

[i82much]

Thanks guys. I am aware of the cam journal issue and if I repair or rebuild this engine I will be sure to use a grooved cam.

Let me ask this question - what are the odds that I install a hyd roller cam and lifters in my driveway in an old 396 and the lifters are still good 50k miles later?

[FC-Pilot]

This is a crazy idea, so bare with me. If I were in your shoes I might look for a gen 6 454 core. The cost of the core might make getting the crank and rods for a 496 out of reach, but what you do get is everything for a hydraulic roller at a much lower cost than retrofit stuff. If you used the crank, rods, block and even the heads and had them all freshened and the block bored for new pistons, a solid 500 lb/ft of torque is not a problem with a cam and spring change. Also, it could keep your truck running with its tired 396 until the new engine was done. You could put a carb on it, or use its efi stuff with an inexpensive controller. There are just lots of options.

After having two budget flat tappet cams go flat in BBC engines over the last decade I won’t put another flat tappet in. I understand budget, so instead of spending $500 on retrofit roller lifters, another $300 to buy a running core would get more bang for the buck in my opinion.

Anyway, it is just a another idea so take it with a grain of salt. (Or the whole shaker if needed. )

Paul

[i82much]

This is a crazy idea, so bare with me. If I were in your shoes I might look for a gen 6 454 core. The cost of the core might make getting the crank and rods for a 496 out of reach, but what you do get is everything for a hydraulic roller at a much lower cost than retrofit stuff. If you used the crank, rods, block and even the heads and had them all freshened and the block bored for new pistons, a solid 500 lb/ft of torque is not a problem with a cam and spring change. Also, it could keep your truck running with its tired 396 until the new engine was done. You could put a carb on it, or use its efi stuff with an inexpensive controller. There are just lots of options.

After having two budget flat tappet cams go flat in BBC engines over the last decade I won’t put another flat tappet in. I understand budget, so instead of spending $500 on retrofit roller lifters, another $300 to buy a running core would get more bang for the buck in my opinion.

Anyway, it is just a another idea so take it with a grain of salt. (Or the whole shaker if needed. )

Paul

it's a fine idea! the main issue i think is the mechanical fuel pump. i have three separate fuel tanks, one in the cab and two saddle tanks. so as best i can tell, I either need three electric fuel pumps or a single mechanical. that's why i am thinking in terms of using what i have or finding an older core.

[dannobee]

Put one inline electric pump on the frame rail.

[FC-Pilot]

I have seen conflicting info on the Gen 6 blocks. Some places say they have a machined fuel pump mounting boss and others don’t. If I were in your shoes the fuel pump thing would be an issue as well, so I get it. If they do have one then I know what I will be building when I have to do an engine for my sister.

I love that you are wanting to build a reasonable engine and not something that would end up being impractical for the application.

Paul

[i82much]

I have seen conflicting info on the Gen 6 blocks. Some places say they have a machined fuel pump mounting boss and others don’t. If I were in your shoes the fuel pump thing would be an issue as well, so I get it. If they do have one then I know what I will be building when I have to do an engine for my sister.

I love that you are wanting to build a reasonable engine and not something that would end up being impractical for the application.

Paul

the new 502 blocks have the boss for sure, it’s the cam on the HT502 that’s missing the lobe. pretty sure the 502 HO and the zz502 both have the lobe now too.

as far as practicality goes, i guess i learned my lesson once already. i have a 65 GTO with a 505 aftermarket Pontiac block. I was running a single plane with an AED 850 double pumper with a machined choke horn. Ran great but we moved to the country and I started wanting to drive it more in the cold. So I put a Quick Fuel with a choke, what a difference!

Then I noticed it was a little tough coming up the driveway with the manual trans and the single plane being just a little soggy, so you either kind of had to drive fast enough to kick gravel up on the paint or feather the clutch and throttle a bit. So I put a dual plane on it and now it almost walks right up the driveway at idle in first. It’s not noticeably less powerful, still gives you a giggle when you smack it and gets driven more now that it’s easier to live with.

As for the truck, all it needs to do is plow snow and go to the dump, really. I use it as a substitute for the GTO in the dead of winter when they spray the roads, the truck isn’t nearly as nice and I don’t really want it to be!

[i82much]

Put one inline electric pump on the frame rail.

i will take a look at it but i thought i remembered convincing myself that the pump would be too low to make me happy. i want to be able to take the truck hunting and drive over stuff!

[bobmc]

the lifter bore alignment can't be that bad if it's still running after 50 years, what rpm are you planning to run? big valve spring pressure is what wears out roller lifter bodies, what's the open spring pressure on the L29 engine-250# maybe?

[i82much]

the lifter bore alignment can't be that bad if it's still running after 50 years, what rpm are you planning to run? big valve spring pressure is what wears out roller lifter bodies, what's the open spring pressure on the L29 engine-250# maybe?

i can’t imagine running this engine hard. my current engine pulls about 18” of vacuum in gear and i would like to duplicate that with the hydraulic roller. right now it seems to give up over 4500 RPM, whether that’s the cam or just weak old valve springs I couldn’t really say.

i would expect to set the rev limiter at 5500 and get one of those TH350 adjustable governor kits to play around with shift points if I went hydraulic roller. i wouldn’t be surprised if I wound up with shift points below 5000 RPM.

i hadn’t thought of the fact that this engine, while old, almost certainly hasn’t seen much spring pressure during it’s life. i got the engine installed in a 72 K10 that I bought. the engine probably went from stock configuration to a rebuild for the truck and hasn’t lived a very tough life.

[HDBD]

Are you sure some sort of sentimental attachment is not getting in the way of achieving your goal?
There are lots of ways to get this motor or another BBC to work great in a truck that tows pulls plows and does it all every day. Still not breaking the bank. It does not take any higher end machine work either. square decks, good bore and hone, line bore correct, a mild hydraulic roller. Even the old 396 manifold and quadrajet will be a star performer if rebuilt. Headers help a lot but also add the potential for maintenance. An HEI.

[bobmc]

going to need 350-400# open spring pressure to run 5500 with hyd roller, know nothing about plowing snow and happy about that

[i82much]

Are you sure some sort of sentimental attachment is not getting in the way of achieving your goal?
There are lots of ways to get this motor or another BBC to work great in a truck that tows pulls plows and does it all every day. Still not breaking the bank. It does not take any higher end machine work either. square decks, good bore and hone, line bore correct, a mild hydraulic roller. Even the old 396 manifold and quadrajet will be a star performer if rebuilt. Headers help a lot but also add the potential for maintenance. An HEI.

i don't know if it's sentimental attachment or, more likely, paralysis by analysis. I think too much. Here's an example of my chain of thought:

(1) 396 starting to seem tired, vacuum looks a little waffly.
(2) Read 2,478 forum pages about flat tappet failures causing vibrating vacuum gauge needles.
(3) Convince myself I need a new flat tappet cam without actually confirming as much.
(4) Pick out flat tappet cam and lifters.
(5) Realize I should probably swap out the springs and retainers too.
(6) I haven't done a cam in ages. I'll probably drop a valve changing the springs. May as well take the heads off and have them looked at, the vacuum issue could be valve guides.
(7) Man, this is a lot of work. I should probably upgrade to a roller while I'm in there. No point in having another flat tappet failure.
(8) Wait, a roller upgrade will be $1k, plus the cost of getting the heads redone and all the work on my part. I've already got a broken exhaust manifold stud and the oil pan and valve covers leak and look pretty beat. Why not pull the engine and have it rebuilt, knowing it is done right?
(9) Ok well if I'm replacing rods and pistons, I may as well see if I can't add a stroker crank while I'm at it.
(10) Well, looks like piston options for a stroker 396, especially with closed chamber heads, are limited and everyone says it is more cost effective just to find a 454.
(11) Scour craigslist for 454 blocks, realize a virgin block is hard to find and pretty expensive, I'd still need at least open chamber heads, and I don't feel like driving around on weekends to look at a bunch of blocks that are already .060 over.
(12) Start looking at new crate motors - hey, I can get a new block, forged pistons, rods, and crank for $6500 brand new with a roller cam for 6500!
(13) Read about GM 502's. Realize the HT502, my best candidate, doesn't have the fuel pump lobe. And the blocks can only take one overbore, from what I hear.
(14) Oh wait, Brodix has a block now? But people say it's not as good as the Dart. But you can start at a 4.500 bore with a Dart block and still go up to 4.600! And the rotating assemblies aren't any more for a 540 than they are for a 496. So just do it once, do it right - roller cam dart block with edelbrock 110 cc heads. You'll never outgrow it.
(15) Realize I just went from thinking that maybe I might (or might not) have a bad cam in my 396 to buying a brand new 540 that will destroy my stock TH350 in short order. Start thinking about flat tappet cams again, or maybe even something really crazy, like actually figuring out what is wrong with the engine before I start replacing the cam.

Everyone else does this too, right?