drovak

The machine shop found cracks between the bolt holes and the water jacket—seems like that's the same as your block, Bob. They installed brass sleeves in the bolt holes. I'm not sure that will do much more than the silicone on the bolts I found while disassembling, but so it goes. They also drilled and sleeved the valve guides, and took off 0.010" or so from the head surface to get it flat again. Then they repainted my head silver—and didn't do a very good job of it. Now I need to figure out what paint was used before. I suspect it could've been Austin Healey Green from POR-15, though I have no way of knowing for sure. It's pretty dark, from best I can tell. Before: After: My head bolts are showing some corrosion, and one has already been replaced. Where can I find a set of new bolts, and hardened washers while I'm at it? Is there another engine that uses the same 5.5" 7/16"-14 bolts so I can just ask the parts guy at O'Reilly's for a set? I'm not having much luck sourcing them online... McMaster sells them, but they're zinc plated in grade 5.

Just checking again if anyone has any thoughts on the Marvel dashpot. How can one determine if it's functioning correctly? I suspect if the dashpot is slow to move, the mixture will remain richer for longer during acceleration, but will settle out under constant load.

I'm not a very tall person, but I found that I could probably use another couple of inches of legroom more than the seat offers, and perhaps some adjustment of the steering wheel in my 8-86. It seems like someone adjusted the position of the seat before, effectively moving the back stop forward about an inch—notice the three visible drill holes near the rear bracket. The front brackets are touching the upholstery, so some work would have to be done to free up some space to move the two front brackets towards the front of the seat. Any thoughts?

The bolt certainly moves a little, but only a fraction of an inch. That doesn't seem like it would do much, even after "amplified" by the lever arm. This thing also has to overcome the force of the spring (which is missing in my shutter assembly, below), so I'm thinking it's not so good after all. I'll be in touch with Scott and see what he thinks. Good call on the lubrication. I was about to ask about that, as my slats are clearly in need of some. Any reason a little grease couldn't be used after complete disassembly and cleaning?

Lastly, here's the bespoke linkage—quite the art piece. Looks like someone bent some steel strap. If anyone has a linkage for sale, or could sketch out the proper dimensions so I can get one machined, I would be ever grateful. I did learn that there certainly doesn't feel like any spring tension on the louvers, but the Sylphon would've had a hard time working against a rusted lever arm anyways.

I spent some time cleaning up the Sylphon. Also gave the cover a good scrub inside. Still have no idea what that crusty stuff was, but it was quite difficult to clean off.

Lucky me, as I didn't have to resort to the drill and tap set! Only had two screws break off at the head, and the rest, while resisting, came out fine on their own. Guess the penetrant oil worked. Seems like there's some takeaway here about patience...eh, forget about it. Cover removed. The linkage was frozen tight on the cover, so I gently unscrewed it, cover and all, pulling it out just enough to clear the remnants of the screws. Now, what the heck is that gritty, yucky stuff? Can't say I've seen anything like it before. Nothing should've been in that cavity, but clearly it filled up with something at some point. Sylphon removed. Shockingly, I hear fluid in it, and it seems airtight. Wow. I'm not sure I am ever that lucky! Oh, and I think I found the oil in my coolant. Definitely sludge in the radiator. Probably a nice mix of stop-leak, oil, coolant, and who knows what else. I had successfully extracted the two broken screws at this point.

A little more investigation shows that it would indeed need a backing plate...what kind of screws or bolts should I source for this? The heads obviously need to be thin enough to not interfere with the hood when closed.

What's the proper way to take this hood apart? It doesn't seem glaringly obvious to me. Front side seems to have the remnants of a screw? Back side:

My '31 8-86 is missing the oil filter. It's been bypassed at some point. Given that the manual suggests changing the oil 4 times per year or every 500 miles, was a cloth filter even that useful? Better than nothing, I suppose! What do you recommend for drivability? I would like to locate an original filter housing for originality at some point.

Don't know the exact terminology, but the two screws that hold bracket fastening the hood hinge at the firewall have both pulled out on my '31 8-86. Seems like that's a high stress point. What's the proper fix? Can I do anything to help alleviate this in the future?

Fortunately, I am prepared! However, what I'm realizing is, the more I dig into this car, the more I realize that the "frame off" restoration it got in the '80s was maybe not of the highest quality, and certainly, certain things were overlooked. Not totally surprising, but a little disappointing nevertheless. Nothing to do but to keep working on it, "one piece at a time!"

Thank you! Very helpful. I guess I will also have to drill these screws out, as they are definitely not wanting to budge. Dang!

Thank you as always, Bob. I can't even get a single screw to budge, allowing me to remove the thermostat. Sigh. I'll let some penetrant soak in. I'm gathering the previous owner probably didn't care that the shutters were stuck open.

Got the sleeves out. One was much tougher to get out than the other, or perhaps I just improved my technique from the first to the second. Glad I got them out, though. The holes were definitely larger than I first thought.

On my '31 8-86, a previous owner used stop-leak. I would optimally like to get rid of all traces of it and actually fix the problem instead of patching it. Will a standard radiator shop likely be able to take good care of cleaning out my radiator? I noticed the thermostatic shutters are always open. Is it common for the thermostat unit to fail? What tips and tricks ought one follow to get this serviceable again?

Good deal. I'll have the machine shop do a thorough inspection of the head when I take it in this week. Please check my first post in this thread for pictures of the head bolts holes; is that what you're describing? Other than authenticity, is there a problem swapping the head bolts with all new ones? The previous owner already replaced one of the two head studs with a new bolt. Is it a common thing to replace both studs with bolts, at the risk of making head alignment slightly more challenging?

I am trying to understand how I have a clear leak in the heat exchanger (tested by lightly pressurizing the oil side with the exchanger submerged in water, with bubbles clearly coming out from the coolant side) yet have no sign of oil in my coolant. I figured the oil pressure would be greater than the pressure of the coolant system, hence I should see oil in the coolant. Instead, I've only observed coolant in the oil, and seemingly more evidence of coolant in cylinder 7 than the others. What do you think?

I inspected the oil heat exchanger, and there is indeed a leak between the two sides. However, I'm not sure that explains everything, like why cylinder 7 had evidence of more coolant than the other cylinders, or why there was zero oil in the coolant. Nevertheless, I'll be bypassing the heat exchanger soon.

My '31 8-86 seemed like it would idle quite acceptably, but if you give it any accelerator, it immediately backfires through the carburetor. I feel like I've got the float level adjusted adequately, right near the top of the idle jets. Could this be indicative of a loose dashpot? Does it require any sort of lubrication? The spring looks good to me. I am aware of two small pinholes in my heat exchanger tubes, but I suspect those should mainly affect idle performance, considering how small they are. However, I'll be addressing that soon. I'm pretty sure my venturis look good, as well. Does it look like one was replaced prior to my ownership? One doesn't look like the other. Another thing I wondered: how soon should the mixture valve open in the accelerator travel? I figure that might also cause similar symptoms if it's not opening soon enough... Also, what are the appropriate jets for this carburetor? When I had it apart before, I seem to recall reading "120" on one of the HS jets. I'll have it apart again to double-check the others. Thanks!

Also, am I missing any literature for working on this car? I thought the manuals would have more in the way of step-by-step instructions for removal and assembly of various things, but that's not the case. My MGB shop manual is far more detailed, but perhaps people just inherently knew what they were doing back in the '20s and '30s!

Excellent. I'll check the heat exchanger soon. Where do you guys recommend getting a gasket set for this engine? While I have things apart, I'd like to replace every gasket I can. I noticed that the exhaust manifold gasket failed. Is this a common problem with these copper gaskets? Is there a specific gasket material recommended for longevity? Also, for things like new intake/exhaust studs and head bolts, is there a vendor that sells these, or should I plan to get them made at a machine shop? In other news...has anyone seen 28 AWG magnet wire used instead of steel safety wire before? I think there's a reason aircraft mechanics don't use copper! In other other news, what's this broken spring for attached to the cover for the (still invisible) timing mark?

I'll give the aluminized exhaust tubing a try, if I can find the right diameter. Seems like that will conform better than stainless. But whatever I use, I'll be sure the measure thrice!

Great info, thanks! I'll dig into that heat exchanger in a couple of days. What's the easiest way to disassemble that side? Can the generator and water pump stay in place for this operation? Happy Thanksgiving!

Here's the underside of the head. I think I'm seeing some unevenness in combustion, on the lean side for most cylinders.