BritishV8 Forum

Sounds like a good plan. What I've learned about the oil level is this. If the oil level is too high, the crank assembly will whip it with the results being about what you would expect. It doesn't take as much as you would think. Disregarding the filter the '65 Buick 300 had a pan capacity of 4 quarts. We tend to run a much smaller filter on our cars than one that will hold a quart so if we put in 5 quarts at oil changes it overfills the pan. Your dipstick may or may not reflect this reality.

Here is my experience. With the stroker which has that 3/16" thick pan spacer and umbrella exhaust valve seals, after putting in 5 quarts of initial break in oil to the clean engine, it smoked, and it didn't quit smoking until after I had done an oil change and then removed almost a quart of oil to get back closer to that 4 quart figure. And then it was perfectly happy. Most of that smoke was coming from the passenger's side so think about how the windage was occurring. My best guess is, too much oil thrown up into the cylinder bores and overcoming the rings but it's hard to say for sure. That oil could then migrate into the intake by reversion so the PCV may not be entirely to blame. In any case it's clear that windage and whipping of the oil will increase the oil sucked out by the PCV regardless of where or how it's plumbed in.

It's perfectly safe to run 4 quarts as long as you aren't losing too much oil pressure in the turns. One quart low in the pan means the engine has 3 quarts of oil available to it, actually a little less when you consider the configuration of the pickup. And that's the point at which we are expected to add oil. Might not be the best practice for a Buick engine but it hasn't resulted in any exceptional number of failures. A public skid pad (Roundabout) is a reasonable place to test. So this is a pretty easy check to make.

One might think, being a stroker that the crank would be closer to the oil and that's right, but not by much. The stroke increases between the 300 and the 340 from 3.4 to 3.8 inches meaning the crank swings .200 further down but then you have to subtract that 3/16" stabilizer plate and that leaves only .012" which isn't enough to make a difference.

Jim

Yeah, that's the other concern that I have been working on, excessive oil in the intake manifold. When I had the supercharger off, to have the rotor pack rebuilt/coated I noticed a significant amount of oil in the intake manifold.

After seeing this, I ran a bore scope through the spark plug holes and there was a lot of carbon build up on the pistons due to the excessive oil in the intake. Suspecting stuck/carboned up piston rings, I performed a leak down test and found several cylinders at about 20% leakage. This of course only compounds the problem, due to excessive crankcase pressure.

To de-carbon the engine, I like to use GM top end cleaner. My preferred method is to use an oil squirt can with a piece of vacuum hose and fill the cylinder with top end cleaner so that it covers the piston. Then I will let it soak overnight. The next day I will insert a length of 5/32" fuel hose connected to a cordless drill through the spark plug hole. Basically, I'm using the drill to flop the hose around to splash the top end cleaner around. Then let it sit for a couple more hours, after that I'll suck the top end cleaner out with a brake vacuum bleeder. After the fluid is sucked out, then I re-inspect for carbon with the bore scope. This process works best with piston down and the oil pan off. (it allows you to capture the top end cleaner in a drain pan)
The process is slow going and it takes a few days, but the pistons look like new. Once the pan is back on and it has oil in it, I'll crank it over with out the spark plugs installed to clean out any remaining top end cleaner.

After de-carboning the engine, I performed another leak down test and all cylinders are coming in at 2% to 3% leakage, so I'm feeling pretty good about that!

Getting back to how the oil/carbon got there in the first place. It appears to be sucking it in through the PCV. I have a catch can on it, but it doesn't seem to catch much oil.

I suspect what may be going on is that there is too much oil being retained in the windage cloud. A problem that only got worse when the piston rings carboned up.

I'm going try a couple of things to see if I can improve the situation.

Although I did have a horizontal baffle in the oil pan, I decided to make a better one that has more coverage. Also, I raised the baffle up about a 1/4" to make sure that it's slightly above the oil level, when there is 5 quarts of fluid in the pan.

Since I don't have a windage tray, I have a crankshaft scraper coming (should be here today). Supposedly there is a slight horsepower gain by using a scraper. I'm more concerned about controlling the quantity of oil retained in the windage cloud for oil control purposes, than I am about trying to extract every last bit of horsepower.

Once it's back together, I'm interested to see how de-carboning the engine and having better oil control effects the EGT readings. I would think that with better ring seal and less carbon build, that it will equalize the cylinder-to-cylinder readings somewhat. If it does, then most likely I will go in and adjust my injector fuel trim settings for optimal performance.   

The brake bracket arrived yesterday and the fit is going to be tight (what isn't on this car?) but I think it'll work, which is pretty much the same as me saying I'ma make it work regardless.



An adapter plate between the bracket and the booster is needed for two reasons, because of the bolt pattern, but more importantly to get room inside the box for the pedal attachment.



As you can see, even trimming the rod back to the minimum it'll need some room and the only thing that immediately jumps out at me is spacing the booster forward. But there may be a better way. Trimming the piston won't work as seen here:



But creating a socket in the brake pedal arm itself could do it.
From the second image it's clear the brake arm has already been modified a bit and I've also modded brake arms, there's nothing sacrosact about them as long as they don't deform or break under pressure. It would be pretty simple to shorten the threaded part a bit and weld a blind tubular socket into the arm in place of the existing pin hole area. This might even let me simply bolt up the booster by drilling a new hole pattern and welding up the old ones. That would preserve the overall length and clear the headers. Yep, sounds like a plan.

I'm pretty sure the rod is held in by a threaded ferrule that takes a specific tang tool to remove but that wouldn't be hard to make, I've done them before for dashboard nuts. So I can avoid grit around the modification and precisely shorten the rod, important for the brake pedal dead zone.

Another consideration, the Hydroboost (ATE H31) runs on ATF with seal materials used accordingly so there are seal compatibility issues with the Lucas pump. Switching seal materials may not really be feasible so the simple answer is to use a compatible pump. But this isn't so simple. Such pumps are generally set up for continuous use with either transmissions or steering, completely unnecessary with brakes. So they need an accumulator and a switch at the very least, as well as a manifold block, usually containing a pressure relief valve. While I don't mind making up the manifold, the parts cost is starting to climb with an $80 pump, probably a $140 accumulator, and another hundred in the switch, pressure relief and fittings. So 300 here, 400 there, another couple hundred over there and we're at about a thousand without labor and that's just for the boosted brakes without the ABS and I still don't have a reservoir. I don't see anyone else doing this right away even though it is kinda cool... On the plus side I definitely should be able to put the parts together in such a way that it all sits on the firewall shelf.

Jim

I expect that will work Bill. In my case I have a 3/16" thick stainless stabilizer plate stacked between the pan rail and the pan so there are two layers of sealant. I'm using black Gasket Maker, I think a good quality sealant is needed here but something like Right Stuff would be a mistake. (BTDT) Dropping the parts in place and coming back in a day for final tightening is the usual drill as you want the sealant to make good contact all around but also want to compress it a bit. Again in my case a two stage process as torquing the main caps is part of the procedure.

Ordinarily you would think that attaching the pan this way would be good enough and sometimes it is. But sometimes it isn't. The right amount of sealant is important, I aim for a bead of about 1/8" but that's hard to achieve uniformly in practice. I go around all the bolt holes, I think none of this is really new. Surface cleaning is absolutely crucial as any slightest small smear of oil will create a leakage path. If the sealant does not immediately adhere in any place it will end up leaking. It doesn't have to be blemish free polished metal by any means but the sealant has to stick and I think this is where most of us find trouble as we inevitably find that spot 3/4 of the way through applying the sealant and don't want to stop. Ideally we would have a primer of some sort that we could brush on both surfaces and check for bad places but I don't know of one. Chances are good it exists though. Anybody?

The flange is a problem of course. Nothing that flexible is going to mate perfectly except under ideal conditions and this is where the old cork caskets came in. However, they are subject to improper torquing and drying out. Almost nobody torques them properly near universally overtightening, the flanges deform, and they were never intended to last past the warranty period which at the time was 2 years and a little over 20k miles and that was stretching it. Not exactly what we are looking for here. So the gasket maker sealant has become the replacement but it isn't as perfect when it comes to filling gaps as we would like to think and sometimes needs a little help. What tends to happen is that all the sealant gets squeezed out at the bolts, the pan rail flexes and bends, and gaps form between the bolts, especially at the corners. A stringer or spreader somewhat like you see for tin valve covers would help but it would take so many of them that you might as well have a single piece of thicker steel.

Alan Mackin over on BuickV8.com (AMACK) makes a very nice set of 1 piece spreaders for the tin valve covers and I've mentioned that one for the pan might be a good idea. It uses a 1/2" strap set edgeways with tubes for the bolts to go through so it concentrates the clamping force on the inner edge of the flange. He just missed getting me a set of the valve cover clamps in time for the BV8 annual auction but they will be there next summer. By then it's possible he'll have the pan piece done if he sees the need. It's something we all could use and I hope we get it. That could already be available as the Buick 350 uses the same pan but the BOPR is different.

Another crucial upgrade is at the oil pump cover. Typically not enough attention is paid to this area and it's just assembled as an afterthought without much of an understanding of how it works. The key consideration is that this unit is a hydraulic pump. As such it is at it's core a precision assembly and should be treated as such. As with all such pumps the gear end gap is crucial and should be held to the absolute minimum necessary running clearance. If that number approaches .005" it is way too much and poor oil pressure will be the inevitable result. As for leaks, careful work here is required and 3 areas need attention. The spacer shims, the cover bolts, and the big nuts/fittings. Once the end gap has been established each surface of each shim and the housing and cover should be properly cleaned and sprayed with a sealant before assembly and promptly assembled and torqued, followed by a rotational check. Absolutely no Vasaline should be allowed to touch the mating surfaces under any condition. The cover bolts should ideally have a flanged head. Copper sealing washers should be used under the cover bolts. The bolt threads and internal threads should be cleaned and degreased and a quality sealant liberally applied to the threads on the bolts that break into or are situated inside the internal cavity, all the bolts can be thus treated, the sealant will act as an anti-seize at disassembly. The big nuts should have a proper sealing washer or o-ring and be tightened suitably. I prefer copper washers, YMMV. If a fitting is used or an adjustment screw, steps should be taken to insure an oil tight seal.

At the rear main cap, I have taken to injecting sealant into the side cavities with a caulking gun and a short stub of plastic tubing, a needle if you will, making sure the sealant comes out the sides at the root where the corners of the cap have been beveled and filling the side groove all the way up. That and a smear of sealant on the parting line over to the main seal seems to do the job. The seal ends should be offset from the parting line and treated with sealant where they mate. The use of sealant in the main seal groove is a good option but don't overdo it. The two piece rubber main seal works if the hash marks have been ground off of the seal journal. This reduces the diameter by around .005".

I don't think that having the main cap sunk .020" below the pan rail is a problem that can't be overcome by the sealant but that's a judgement call. A filler piece could help provided the surfaces are well prepped, otherwise I could see it getting dislodged.

Make sure there is a clean surface for the front main seal to ride on of course, and the same processes applies generally to the front cover of course. Having narrow bands where it contacts the block, extra care is required. Some consider the gasket essential here, some do not. Your choice, both can work.

Finally, the intake. Much here depends on the fit of your intake at the front and rear of the block and the closer that is the better. Rubber seals were used to allow for surfacing of the head later on and you can use those and most do I think. Some have had success with building up a large sealant bead here. I think the only ideal solution requires fabrication and on a production intake the idea would be to add pieces that will constrain the seals to the area they are intended to serve, both inside and outside of the lifter valley. I am not yet aware of an ideal solution but don't feel it would be hard to do. In my case a custom intake removes the issue. On the BOPR you have the lifter valley pan and the neoprene coated Rover part is a good one. The aforementioned spreaders made by Alan Mackin handle the valve covers if you are not using cast aluminum ones, and the last consideration, well two really are oil level and PCV. Do not overfill the pan.

Jim

Good write up Jim.

On the pan oil leak front, I've been battling that for a while. It wasn't horrible, but enough to cause some drips on the shop floor and annoy me. I tried some of my usual tricks, straightening the pan, different types of gaskets and sealer, etc. It would be good for a while, then slowly it would start leaking again.

I think that I have it figured out though and have traced it down to a couple of things.

My block has been line-bored, and it is standard practice to remove some material from the main caps. Then the caps are torqued in place, and the block/caps are re-machined round again. Upon closer inspection, I noticed that the rear main cap (which also serves as the rear engine block close out) was recessed .020" from the oil pan rail edge surface of the block.

Also, my oil pan rail edge wasn't in the best shape, probably due to age and to many R+I attempts. I ended up cutting of the old mounting flange off the pan. Then I fabricated a new one-piece flange out of 1/4" thick steel plate. Fortunately, I have a spare engine block, so I was able to weld the new flange to the pan, with it bolted to the spare engine block. The flange/mating surface was machined flat using a combination of a large stationary belt sander, straight edge and files.

To address the recessed main cap, the plan is to make a .020" "shim" out of gasket material. Then I think I'll use ThreeBond RTV instead of an oil pan gasket.

Hopefully this will do the trick, as I am on a mission now!

Bill

The booster came in and it fits up to the MC correctly as far as appearances go. Odd thing, it has a black plastic insert that sticks out maybe 1/8" but gets pressed back in when the MC is bolted up, it appears to be spring loaded. Can't say I've seen that before. Overall length from the flange is 11" which is good but stickout into the pedal box could be a problem.

The reservoir also came in and the spacing on the spigots is right (85mm) but the spigots themselves are of a smaller size than the grommets were made for. Plus it needs extra fittings for the pump drain and return. Assuming the pump and booster isn't run as a separate system. I need to look at the plumbing for the Mk60e5 ABS unit to see where it gets it's pressure. I can use it for mock-up to evaluate reservoir size and placement. The pedal box should be in tomorrow.

Jim

Quote from: BlownMGB-V8 on November 04, 2026, 08:13:06 AMProbably similar but the bore size and the stud spacing are different. I think MG is 13/16" and this is 1". Pretty sure on the MG the studs are 1/8" closer together.

The mounting on the MGB brake master is a bit of an oddball.  I had to use an adapter to bolt the OEM to a dual brake booster.

Probably similar but the bore size and the stud spacing are different. I think MG is 13/16" and this is 1". Pretty sure on the MG the studs are 1/8" closer together. The spacing on the reservoir nipples may also be different, I think these are 75mm apart from memory, I may have ordered the wrong reservoir but I guess I'll find out Friday. It also needs a port for a line from the pump which it doesn't have. Looks like I got in too big of a hurry about ordering that part.

Still waiting on parts. The late pedal box is due tomorrow and the hydroboost should get here today. The reservoir should get here Friday. I should probably see if I can get a rebuild kit for the hydroboost.

I'm hopeful that once I swap out the pedal box I will have room beside it for the pump/accumulator unit.

Jim

Quote from: MGBV8 on October 29, 2026, 10:32:10 AMLook a lot like the OEM on my '79 B.

Looks like the one on my TR7 too.

Today I connected the red wire to the starter at the large power terminal and got power to the ignition/fuse panel. In reading a few different articles on the Olds 215 Starter circuit I came across one that showed power going from the starter to the ignition circuit and immediately realized I had messed up with that loose red wire with the large ring connector. I probably have a picture that showed how those wires were connected when I took it apart. Thanks guys for the help!