MG Sports Cars

I was hoping to be there...

I thought we did very well today getting the engine out and on the stand. No real surprises so far except I was kinda disappointed with the lock washers on the flywheel bolts and think we might just leave those off when it goes back together. We also had a bit of a struggle getting the radiator out so we might massage that area a bit to make things a little easier in the future. We also need to do some work on the dipstick tube and see if maybe we can come up with a better location. But everything has gone pretty smoothly. We'll pull the heads off tomorrow and take some measurements, maybe get the pistons on order.

Jim

Now that the work session is over I'll do my best on an update. Some good news and some bad but overall not exactly what we expected. First off, the bores look pretty good with no wear but #4 had some scuffing at the front of the cylinder and I question just how well the rings had seated due to some uneven looking places. I'm pretty sure those were chromed rings and that may not be the best choice next time. We took measurements and determined that this engine had a static compression ratio of 9.13:1 which is really quite acceptable, and we don't feel that alone would justify a piston swap. The cam is a Crower dual pattern # 52241, it has a valve lift of .514/.525 and duration @.050 of 230/236 with 112 separation. May not be ideal for us but not bad. Probably not off enough from ideal to justify a cam change. The bearings were badly worn, down into the copper with one rod bearing particularly bad but the crank journals were not scored. Cam bearings look just fine. Head gasket leakage was visible in places where the radiator sealant had built up on the block but no visible damage to either block or heads. We suspect small quantities of antifreeze leaking into the crankcase over time caused the bearing wear.

Dan will be delivering the block, heads and piston/rod assy's to the shop later today and I plan to call Dustin to let him know what we want done. After his initial cleaning and inspection we will decide how best to proceed. We will need to buy rod and main bearings and new rings of course. We have $740 in donations received for the piston upgrade.

Now, since those donations were for the specific purpose of buying new pistons, I need to offer to refund that money to anyone who does not want it used for bearings rings, and machine work instead. If you fall into that category please contact me and I'll send your donation back. Otherwise we will use it to refresh the engine. I figure the bearings and rings will eat up over half of it and Dustin's services will easily eat the rest and very likely more besides. So what I'm saying is that anybody else who would like to contribute would be very welcome.

I expect charges for cleaning, inspection, crank grinding, finish hone, and possibly resizing rods, and skimming the heads. The #4 cylinder is going to be a judgement call. The scuff marks are just barely deep enough to catch a fingernail but you can feel them. There are a couple ways we can deal with them. Cheapest and easiest is a finish hone that leaves visible marks. The engine wasn't burning oil and we wouldn't lose any substantial amount of compression so performance wouldn't be affected. Next step is if we could get the same piston .050" over and hone to that size in that cylinder only, which may be a possibility. (The current pistons are .040" over) I think the crank was 10/20 undersized so we'll just have to wait and see whether we can reuse it or not and still get the required clearances. I will know more in about a week.

Jim

That cam should have more compression. IMO, it is two or three sizes too big. A 52238 or 52239 would be much better for our use. On the other hand, if in good shape...

I hope those TA heads do not need to be skimmed. Maybe the block needs a slight decking? A .5-.75 compression bump would be good for the cam we have.

Update. The engine is back together, in the car and has been on a short test drive. We had a few issues along the way, a few more parts needed, and our expenses have run about $125 short of donations which was more than I'd hoped for but at least we are still in the black on this refresh. Machine shop costs including main, rod and cam bearings and rings was a very reasonable $845. Mains alone were about $130. Unplanned expenses included 2 oil & filter changes with Lucas additive, synchromesh oil, antifreeze, alumablast paint, shifter boot, oil sender, dipstick etc. It adds up so in total we spent around $1600, part of which was for gaskets, seals, cam and lifters. I think we did pretty good.

Dan and Steve were here for a couple of days during which we assembled the engine, put it in the car, reinstalled all the major parts and ordered parts. I got to finish it up afterwards, which has taken a few days.

My impression after the first drive is that maybe there's a cylinder or two not firing. Definitely down on power and feels like a miss. Oddly the exhaust ports on the off side are warmer than the ones on the driver's. I'll be looking a little closer at the plug wires since we had those off and maybe that will be the problem. Indications are that the rings seated almost immediately and starting is just like it was before. Main seals are doing fine both front and rear and so far it's all pretty dry underneath. Hopefully it'll stay that way.

Jim

Great news Jim.. Thanks to Dan, Steve and you.

Jim, Dan, & Steve - thanks for getting it this far! Looking forward to hearing what's up with the power levels. Hopefully just bad plug wires or not in the right order.

Jim, Dan, & Steve - thanks for getting it this far! Looking forward to hearing what's up with the power levels. Hopefully just bad plug wires or not in the right order.

It had 1 wire that had pulled out of the boot. I re-crimped the end and it's fine. I've been driving the car for the last couple of days, got probably 25-30 miles on it now.How does it compare to before? Well it's easier to start and easier to drive (not that that was a goal or anything). I no longer give it any gas when I let out the clutch, just make it a 2 step process. Let the clutch out, then give it gas. It is extremely smooth and controllable off idle. Edith could drive this car easily, and she doesn't do stick. As for the power, it's there. I'm not sure if there is as much as before or not, my guess is probably not but we're still in the break-in stage so who knows? I don't think we could tell without a dyno and since we never really got a satisfactory dyno pull out of it before we could only compare it to the Texas dyno pull which was shut down while the power was still going up. But, it does have "enough" power. It'll be fine.

Be interesting to see how it does on gas mileage.

I've had to back off the idle speed screw once already and need to do it again I think. I take that as a good sign. Oil pressure is above the midway mark always. BTW that gage is inaccurate by at least 5psi reading low. We've got about 45psi or more at warm idle and the pressure relief opens about 75. Anyway as long as it's in the upper hemisphere, no worries.

The horn doesn't work, cruise control doesn't work, and the swaybar contacts the tires on a hard turn (like when parking). But for now I'm working on my bus. Then I need to get my car on the lift to adjust the emergency brakes and put the summer tires back on. After all that, the oil in the RM will need changed before the meet, hopefully I can get a couple hundred miles on it by then and while it's on the lift for that I'll look at bending the ends of the swaybar. It now has a 1" bar, 5/8" on rear with adjustable linkage and I did the skidpad thing in the church lot and the handling is very nicely balanced. I doubt I'll have time to troubleshoot the cruise but maybe I can look at the horn.

Jim

Jim, what cam did you go with?



Edited 1 time(s). Last edit at 05/25/2022 02:02AM by mgb260.

Stock grind from Melling.

Driving this car and mine back-to-back it's clear it needs the Monroe Load Levelers on the rear so I ordered a set from Amazon. $91.99 which leaves $35.13 of the contributed funds. I hope to get those installed before the BV8 meet.

The horn relay clicks so it's probably the horn connection. I'll take a look at that while I have the car on the lift. Currently have 105 miles on the engine refresh and all is well. Backed out the idle screw and now it idles so slow it doesn't even register on the tach. But it seems a comfortable speed. Tweaking the swaybar has now become the priority item. My car comes off the lift today so I'll see what I can do about that.

Jim

Jim, Are you replacing the coilovers or using the Load Leveler's as additional shocks?



Edited 1 time(s). Last edit at 05/28/2022 12:59PM by mgb260.

Adding them. It means dialing back the springs on the coilovers to get the right ride height, I set it so the wheel flange is zeroed out vertically and then the ride height is adjusted with the axle shims. In this case since we already set that it just means bringing it back to vertical with the spring adjusters. In the end we get a stiffer spring rate and stiffer shocks both of which are good. I will TRY this time to measure the spring rate of the load levelers before I put them on and report back here. Amazon generally delivers within a couple days.

I put the car on the lift today. The swaybar links were too long making the ends of the bar hit the rims. I had a couple of 1/2" stud heim joints on the shelf so went to Menards and got matching pieces and 7/16" grade 8 bolts then came back and made a couple of adapters to match the bolts to the 1/2" heims and bolted it all up. Looks like it'll be OK now. We had some oil leaking out, looks like a valve cover so I inspected the gasket and tightened them down. Slight mismatch on the holes, so I fixed that too. Re-tightened the headers again, didn't get much there which is good. Sprayed everything down to wash off the oil. No leakage from the front or rear seals, transmission, or oil pump but both valve covers were leaking. Hopefully that is fixed now. Think I'll go out and have a look at the horns. The gas I sprayed it with should have dried up by now.

Jim

Curse You Max Fulton!!!!
(Damned, damned. double damned Bullet Connectors!!)
Horn works now.

Jim ;-]

Pretty sure those connectors came with the wiring harness.

It was an AAW wiring harness. Max added the bullets. Tried to tell him they were a bad idea but he just wouldn't listen.

Jim

There are bullet connectors all over most MGBs.

Each bullet connector represents at least 5 and up to 18 failure points. They are exposed to an oxidizer at best and oxidizers plus corrosives if outside the cockpit. If under the bumper like this one was, add road salt and weather. In those conditions it is guaranteed to fail. The only question is how long it takes. Scatter a few of those around the car and your brand new AAW harness is meaningless after the first few years. I won't have them in my car. My electrical problems have plummeted and when they do occur have easily determined causes. I use gas sealed connectors exclusively and have never had one fail. You'll never be able to say that for bullet connectors unless they are brand new. There is a reason they are no longer used in new cars. Because they are BAD! Let oxygen get to your conductors and sooner or later they will no longer carry signals. That's just simple chemistry. But hey, we are all entitled to believe what we want, whether it has any basis in fact or not.

I've been working on the cruise control. This is the Ford system. As it turns out there are at least three distinct variants, distinguishable by the connector on the actuator module. There are two different connector bodies, an older larger rectangular one and a later smaller oval one. Of the rectangular one there are at least 3 variants and you can tell them apart by the holes that are blanked out. I like the one used in my Lincoln Blackwood truck because it's already installed there and in my roadster and I can swap parts to troubleshoot so I installed that one in the RM but the switch module is not illuminated. OTOH the wiring seems a little easier to sort out. It has pins 1, 2 and 8 blanked out. There is also one with 3, 4 and 8 blanked out and the other one has pins 3 and 8 blanked out and as you can see has an extra wire to deal with, also multiple speed signal inputs, all of which may not be necessary.

All the switch modules so far use 4 pins but do not work the same so neither the actuators or the switch modules are interchangeable between systems. So while you can get your parts off different cars you need to be sure the actuator and switch module are compatible by checking the actuator connector. For instance in the older version (90's and early 2000's) the ON switch shorts the switch leads whereas the Focus version (~2008) reduces resistance from about 4500 ohms to 2500 ohms to switch on. I don't know why this was done, but they are not compatible. As the system becomes more complex it gets harder to figure out and less likely to work without all it's original connections into the rest of the system. I know the older system works. I have reason to believe the next one can. Beyond that I'm not willing to say at this time. The oval connector one has 6 wires.

In conjunction with replacing the switch module with the earlier style in the RM and getting that up and running I'm replacing the custom console switch panel in my car with a standard switch module in the ashtray so it is in a more convenient location. My switch panel uses a 60 ohm resistor on a green switched power lead that feeds the ON switch where this feed comes via the horn button clock spring in the Ford module so that's a wrinkle I'm sorting out. That 3rd feed is needed, I just have to be sure it's connected to the right pin. The resistor however may not be needed. That is the resistance of the horn relay coil that the power comes through. More on that later.

Also many of the wheel balance weights have been thrown off. On a pair of my wheels I was successful in restoring balance by replacing the missing weights (identified by the residual 2 sided tape), covering the weights with speed tape and restoring the wheel balance. On the RM it is a bit more difficult as there are residual tapes from multiple balancing operations but I will do what I can with them. Worst case we may need to rebalance the wheels.

Jim



Edited 5 time(s). Last edit at 05/30/2022 11:56AM by BlownMGB-V8.

Still no joy on the cruise but I may fix that today. The question of that 50 ohm resistor has come up.

Cleaned the inside of the wheels (a very dirty and thankless job), added weights where it looked like they might have been and taped them. Here's a useful tip: Ever have trouble sticking the weights and the tape to the inside of the wheel after it's been cleaned? Try painting the area you want to stick to with contact cement. Works great. I used the solvent based type, not sure it'd work with the water based.

Having sealed the valve covers better I now see oil being deposited around the oil filler cap. Might need to review the PVC system.

Jim