[SRGN]

Bickering for no reason. To do it right, teardown and line bore/hone. Or, roll the dice and potentially damage a crank by bolting on a cap from another block. Nobody knows if the block was line bored during the last rebuild, so a cap replacement could potentially go really bad. It's not my engine, not my choice.

Threenuts, if you decide to pull the engine I can tear it down with you one weekend if you want to take it for a ride to my garage in Bedminster. I try to have at least one free engine stand, only thing I ask is that you take everything with you when we're done. When the machine work is done, bring it back and I'll help you reassemble the short block. I have all the proper tools for disassembly and reassembly.

[Skidmark]

Originally Posted by SRGN

Bickering for no reason. To do it right, teardown and line bore/hone. Or, roll the dice and potentially damage a crank by bolting on a cap from another block. Nobody knows if the block was line bored during the last rebuild, so a cap replacement could potentially go really bad. It's not my engine, not my choice.

Threenuts, if you decide to pull the engine I can tear it down with you one weekend if you want to take it for a ride to my garage in Bedminster. I try to have at least one free engine stand, only thing I ask is that you take everything with you when we're done. When the machine work is done, bring it back and I'll help you reassemble the short block. I have all the proper tools for disassembly and reassembly.

I like this option. Nice offer.

[NeighborsComplaint]

Originally Posted by Skidmark

I like this option. Nice offer.

Nice to see a community come together and solve a problem instead of nit picking because a guy said align-hone when he meant align-bore. Actions speak louder than words bantering about. I offered a least invasive method that could be verified as a go or no-go before putting the oil pan back on and starting the vehicle. It's not bad advice when offered with the caution it isn't without some risk either. It's up to the OP to decide if the juice is worth a little squeeze or a big one.

[PAUL K]

I was just trying to help

[Jonsie]

If you decide to ship the engine out, consider Paul Spotts in Hatboro PA, he specializes in Pontiac engines

[hurryinhoosier62]

Originally Posted by PAUL K

I was just trying to help

You should, Paul; you ARE a professional. Didn’t intend any slight toward you. Replacing caps and align boring blocks successfully requires EXPERIENCE and KNOWLEDGE of the process.

[ThreeNuts]

Update: Engine went to Van's machine in Birdsboro on May 11th. They disassembled, checked it out (heads, pistons, rods all good); tanked the block, line-bored in the new cap, honed the cylinders, replaced the rings, big-end rod bearings, all main bearings, seals, freeze plugs; reassembled. Got it back June 8. About seven grand for 48-hours labor and $700 in parts.

Work looks quite competent but they did not know that the oil pump impeller shaft goes in from the bottom, before the pump. Think that's uncommon now. I had to pull the pan and install it, which took all of ten minutes. All bolts marked for torque, which was encouraging. Took far longer to clean down the pan mating surfaces of whatever Permatex product they used in place of an actual gasket. I had a 3-part silicone/metal gasket from Permatex I installed with judicious use of gasket seal at the front apex and across the rear curve. I did call & let them know. Then spun the oil pump until oil came out of the rockers.

Spent last week installing the peripherals;. Installed the carb using only a new thick gasket/spacer, which leaked very badly; wound up installing the old spacer with paper gaskets top & bottom. Had trouble sealing the old vacuum hard line for the brake booster, it's pretty beat-up & rounded off. Ordered a new one; filed the old one to get good enough faces to snug it down. This eliminated the vacuum leaks.

Which showed up on the first start Monday as the engine screamed along at about 3500-RPM, and would die under 2500. I let it get up to 180 or so & shut it off. Once I solved the vacuum leaks it settled down, and yesterday was able to set the timing, mixture was still pretty good. Idling for about a half-hour had it up to 230-degrees plus. Aside from snugging down three hose clamps, nothing leaked and it sounds great



Changing out the Rotella & filter for synthetic, will change that again after about 500-miles. Think we're back in business.

[sdbob]

Glad you got good work and results.
My first 389 build I had to pull the pan back off for same reason.buddy said just grind the tangs off, nope. Again, fall down learn get back up.

[mgarblik]

Glad to hear you are back in business. There are allot of Pontiac related activities with the 100th anniversary and such. Once in a lifetime chance to participate in this stuff.

[PAUL K]

That all sounds great! Glad it's all behind you and you can go back to enjoying your special car

FYI, the ears can be ground off the oil pump driveshaft and it can be installed from the top

[Half-Inch Stud]

Gladness. Oh uhm the oil driveshaft out/in from the top deal is a happy mod if a fella grinds them 2 nubs away.

[TXSTARFIRE]

Is there any reason not to grind the nubs off? I suppose you need to be careful that the shaft is correctly placed when dropping it in.

[John Milner]

The nubs help keep the oil pump shaft plugged on to the oil pump when you pull the distributor out.

[ThreeNuts]

I owe you all a follow up!

Engine runs very smooth. Have put just under 200-miles on it and it runs great.

Two issues. The first is an older one, but still here after the rebuild: Has to be a carburetor issue: it's stumbling a bit when drifting along on neutral throttle at low speeds, and there's a momentary hitch that feels like the accelerator pump is starting to go bad when giving throttle...but while the engine was out, I cleaned and rebuilt the carburetor and it has a new pump in it (the old one was worn through at one point on the leather). The stumbling at neutral throttle - I replaced the metering rod springs - apparently, they should be done at every carb rebuild; this is the factory 4034S, I've had the car since 2000, and I'd never replaced them. They're not in a rebuild kit, so I got a couple sets (one from Mike's) and also picked up a couple pistons in case the springs didn't help. They didn't.

I pivoted first - acquired, cleaned, adjusted and installed another '66 4034S, transferring the accelerator pump (the piston was worn out the same way!) and new metering rod springs. The stumbling seems to be gone, but the slight hesitation is still there. May get another accelerator pump.

Second issue is new: cold start is fine, but at hot start, there's about a half-second of what sounds like valve clatter as it lights but before it catches fully. This is not a 'dry start from sitting' - type thing; only hot starts, and it is momentary.

I set the timing about 2-3-degrees retarded (no vacuum) at the recommendation of the builder, who found heavier wear at the top of the cam bearings and suspected detonation (valves & heads are fine). Is this causing that? Acceleration ain't what it was set this way, and the old man in me wants to advance it a bit.

I also never checked to see if it was actually at TDC for ignition or exhaust (the timing was set right a 0, and I verified visually that the #1 piston was at TDC before installing the distributor). Pretty sure it wouldn't run if it was wrong.

Thank you all for your inputs, critiques and wit! I now have a $7000 paperweight, but she's back running!

[ThreeNuts]

Originally Posted by TXSTARFIRE

Is there any reason not to grind the nubs off? I suppose you need to be careful that the shaft is correctly placed when dropping it in.

That was the thing: I toyed briefly with doing it, but knew I'd miss the pump socket and drop it in the pan anyway.

Do it right. Yes it's the hard way. Yes, it can suck. But do it right.

[SRGN]

Originally Posted by ThreeNuts

I owe you all a follow up!

Engine runs very smooth. Have put just under 200-miles on it and it runs great.

Two issues. The first is an older one, but still here after the rebuild: Has to be a carburetor issue: it's stumbling a bit when drifting along on neutral throttle at low speeds, and there's a momentary hitch that feels like the accelerator pump is starting to go bad when giving throttle...but while the engine was out, I cleaned and rebuilt the carburetor and it has a new pump in it (the old one was worn through at one point on the leather). The stumbling at neutral throttle - I replaced the metering rod springs - apparently, they should be done at every carb rebuild; this is the factory 4034S, I've had the car since 2000, and I'd never replaced them. They're not in a rebuild kit, so I got a couple sets (one from Mike's) and also picked up a couple pistons in case the springs didn't help. They didn't.

I pivoted first - acquired, cleaned, adjusted and installed another '66 4034S, transferring the accelerator pump (the piston was worn out the same way!) and new metering rod springs. The stumbling seems to be gone, but the slight hesitation is still there. May get another accelerator pump.

Second issue is new: cold start is fine, but at hot start, there's about a half-second of what sounds like valve clatter as it lights but before it catches fully. This is not a 'dry start from sitting' - type thing; only hot starts, and it is momentary.

I set the timing about 2-3-degrees retarded (no vacuum) at the recommendation of the builder, who found heavier wear at the top of the cam bearings and suspected detonation (valves & heads are fine). Is this causing that? Acceleration ain't what it was set this way, and the old man in me wants to advance it a bit.

I also never checked to see if it was actually at TDC for ignition or exhaust (the timing was set right a 0, and I verified visually that the #1 piston was at TDC before installing the distributor). Pretty sure it wouldn't run if it was wrong.

Thank you all for your inputs, critiques and wit! I now have a $7000 paperweight, but she's back running!

If there was witness marks on the upper shell of the rod bearings, that would be detonation. Upper part of the cam bearings is more likely an oiling issue or a bent cam. If you want to work on the tune, I have a wideband and a lot of diagnostic equipment. You are welcome to drive up to my little shop and I'll help figure it out. I'm usually up there when I'm not at my regular job.

[ThreeNuts]

Originally Posted by SRGN

Bickering for no reason. To do it right, teardown and line bore/hone. Or, roll the dice and potentially damage a crank by bolting on a cap from another block. Nobody knows if the block was line bored during the last rebuild, so a cap replacement could potentially go really bad. It's not my engine, not my choice.

Threenuts, if you decide to pull the engine I can tear it down with you one weekend if you want to take it for a ride to my garage in Bedminster. I try to have at least one free engine stand, only thing I ask is that you take everything with you when we're done. When the machine work is done, bring it back and I'll help you reassemble the short block. I have all the proper tools for disassembly and reassembly.

For some reason, most of these posts only recently showed up, I apologize for missing them, and am grateful for the offer. Thank you!

[mgarblik]

Glad you are up and running. Couple things to consider. First timing. I would verify TDC is TDC with a piston stop or at the very least a camera to look at the piston and the timing marks. That should get you close. I hate to pick on an engine builder I don't know, but a Pontiac V-8, especially with closed chamber heads won't run it's best at 2-3 degrees retarded timing. The combustion chambers are so inefficient, your fuel mileage and performance will suffer. I can't imagine this engine running well without at least 6-8 degrees advance at idle. To be safe, and avoid detonation, borrow or buy a dial back style timing light. Check your total timing @ 4000-4500 RPM. I think you would be plenty safe at 32-34 degrees. Then see what your initial timing is at idle, vacuum disconnected. Then see what your timing is with the vacuum attached. With todays lousy fuel, you may find the vacuum canister is adding 20-22 degrees of timing at high vacuum. That is where your detonation may be happening. On almost all rebuilds with old distributors, I have to mechanically limit the vacuum advance to 10-12 degrees to avoid detonation on lousy pump gas. This can be done by welding in a stop, installing a screw, or possibly sliding a small diameter sleeve over the post on the vacuum unit.

Getting your distributor and timing straightened out first will likely eliminate your "carburetor" problems. Get the ignition right first, then mess with the carburetor if needed. Good luck with it.

[ThreeNuts]

Originally Posted by SRGN

If there was witness marks on the upper shell of the rod bearings, that would be detonation. Upper part of the cam bearings is more likely an oiling issue or a bent cam. If you want to work on the tune, I have a wideband and a lot of diagnostic equipment. You are welcome to drive up to my little shop and I'll help figure it out. I'm usually up there when I'm not at my regular job.

Thank you! Be careful what you offer; I just might!

I have all of the bearing shells (I always insist on retaining all of the old parts) - I'll check the rod bottom ends...not sure which one is the top one - I guess if they're scrubbed, I'll know...

I did order a new accelerator piston. The issue is not noticeable in Park.

The vacuum was right around 19hg, with a 1"-hg steady flutter, which I keep forgetting is normal for carbureted cars.

I may put the tach & vacuum meters in the car (with really long extensions) and drive it around to rule in/out it being ignition or fuel. It's running the Pertronix system I installed in 2001; I did replace the cap, rotor, plugs & wires along with the coil with this rebuild.

I'll push the timing up & see if the clatter goes away.

[ThreeNuts]

Originally Posted by mgarblik

Glad you are up and running. Couple things to consider. First timing. I would verify TDC is TDC with a piston stop or at the very least a camera to look at the piston and the timing marks. That should get you close. I hate to pick on an engine builder I don't know, but a Pontiac V-8, especially with closed chamber heads won't run it's best at 2-3 degrees retarded timing.

I verified that it was before installing the distributor - my only concern is if I was off by 180-degrees but, having never done that, I don't know what it does. I assume it wouldn't run if the rotor was on #1 and #8 cylinder was at TDC.

Your comment about the builder resonates, especially after the oil pump shaft issue. Maybe that's conventional wisdom for the big blocks that he's seeing on the regular. I have every confidence that he set-up the static timing correctly - that's a fairly standard thing on any engine at rebuild - but the Pontiacs have their quirks, and that timing issue may be one of them.

I was not as surprised by the bearing scrubbing - the car could sit for weeks or even months in the winter (in a heated garage) before I'd start it again, and I did have lifter clatter occasionally until the oil pumped up, so it's my use pattern that did it.

I've looked into pre-oiling systems but damn, they are expensive. Pulling the distributor to spin it is a job on these things. Shop owner suggested using synthetic to alleviate these, and yeah, starting it & warming it up once a week in the winter would probably help. What I need for that is one of those heavy hoses that shops used to use to pipe the exhaust outside with the door shut. I'd cut a port in the garage door.