Blown 346 cid Stroker 300

[BKRMON]

Hmm.  Think I will go check my fire extinguishers.

[BlownMGB-V8]

Always a good idea. I ordered some new nicopp fuel line, probably should have just bought some at the corner store but I'm sure it'll get used eventually. My rear section looks fairly abused but it's only about 4 ft long before it hits a union. That should make it easier to route up and over the suspension crossmember. Might need to do the same for the return which is 5/16" but probably won't need to order more. The vent line shouldn't care about added heat and the hydraulic lines may eventually go away. Current offerings for electric wing cylinders have a wart on the side and only produce 110 lbs of thrust, which I don't think is enough, but they also have a built in cut off switch which could help. I'm tempted to buy a pair of them. If I can't use them on the bonnet maybe they would work for the wing. (I'll need heavier gas struts for the trunk lid but that's coming due anyway.) Might be best to leave the hydraulic lines alone for now.

I did get the headers back in the car and the bends came for the radiator hose. Looks like a little trimming of the belt tensioner bracket and that will line up. Could maybe pull the radiator and weld in a smaller lower neck which would fit the hose better, and a bend could be an advantage, I used one on the old radiator. I could cut that off and reuse it but I hate to scrap out a part that is usable. Maybe I could get a hundred for the old one on ebay?

Now for the collectors I have this:



Instead of this:



You might think 2-1/4 is small for a collector diameter but it's the volume more than the diameter that counts and with a foot or so dumping directly into the 2" perforated tube it should be fine. Based on past performance it'll be quite a bit more than fine.

It's the details that get you on these things. With about 5 weeks left, time is growing short but I'll do what I can. I do have a backup plan at least.

Jim

[BlownMGB-V8]

I think I may have found the electric actuators i can use for the bonnet:

https://www.amazon.com/dp/B0D4LWDZBR/ref=sspa_dk_detail_1?pd_rd_i=B0CPPDLWV8&pd_rd_w=DpylU&content-id=amzn1.sym.bbb3fb5e-28ad-4062-a3ba-1f7b9f2e4371&pf_rd_p=bbb3fb5e-28ad-4062-a3ba-1f7b9f2e4371&pf_rd_r=BSN7AW7FWTCX7XE4Y3JY&pd_rd_wg=JqtFS&pd_rd_r=3e23e957-3b4c-4894-9104-933fec1ed88c&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM&th=1

About $50 ea from Amazon which is quite reasonable I feel. I just have to check the dimensions and clearances. I will have to make new mounts to the big stainless inner wing braces but I'd have to do that anyway. I think the thrust on this one is about right. If it isn't, the good news is they are available at over twice that value. I never liked the wart on the side but I've seen worse. Possibly I can locate that on the bonnet side.

I also ordered stainless bungs for the sensors:

https://www.amazon.com/dp/B0F2SH8RBR/ref=sspa_dk_detail_2?pd_rd_i=B0F2SH8RBR&pd_rd_w=yLPlS&content-id=amzn1.sym.386c274b-4bfe-4421-9052-a1a56db557ab&pf_rd_p=386c274b-4bfe-4421-9052-a1a56db557ab&pf_rd_r=BSZ08WT1FNDJ57CSQTNK&pd_rd_wg=X8s10&pd_rd_r=46de32a6-b57e-4bda-a11c-4bc82e67e75e&sp_csd=d2lkZ2V0TmFtZT1zcF9kZXRhaWxfdGhlbWF0aWM&th=1

These will go on the header pipe below the collectors. I have two O2 sensors, one AFR and one EGT. The EGT gage is for a diesel application that I installed decades ago when I was running the turbo Jetfire engine and it has a lower redline than you'd see for a gasoline engine, but installed downstream it reads lower too so that all works out. I typically see temps on that gage anywhere from 600 to a max of 1500 degrees, typically running around 900 or so. I'm waiting on the perforated tubes to arrive from the UK. DHL has them and their delivery and tracking is sorta messed up. Should be here by the middle of the week but fingers crossed on that one. They also may have delivered them to the wrong address.

I pulled the radiator back out to plumb the hoses. I'm going to add a bend to the top neck to point it at the thermostat housing which will let me get by with a simple hose with one mild bend. The lower hose is tricky of course. I clearanced the tensioner bracket to make a bit more room and plan to use a aluminum bend to come off the water pump and weld a same sized stub in the lower bung position, possibly also with a bend which hopefully will allow two short hose sections to connect up. I do like the ease with which the radiator/fan package is removed/reinstalled.

Jim

[BlownMGB-V8]

I almost forgot... The new fan shroud has to go on over the hose necks. With them both bending upwards that might work but they also both go towards the center which might not. Glad I thought of that before I started welding.

Jim

[BlownMGB-V8]

So that's finished now.



I also cut and plated a small notch in the frame rail for hose clearance and a couple other details.



And set the unit in place to sort out the radiator hoses and that's coming along.



More exhaust plumbing came in including the perforated tubes and the sensor bungs so I'll be able to move ahead with that part.



Also the linear actuators came in and they are cute little buggers. I'll be pulling the last of the hydraulics out and as soon as I've successfully tested the bonnet lift will order units for the wing cylinders also. I'll need a ground sensor and a control unit to make that work properly but I'm thinking that parking sensors might do the job.

Jim

[BlownMGB-V8]

Got the lower radiator hose/pipe combo installed yesterday finally, it was a game of many small adjustments to close clearances but now I'm happy with it. Close quarters and no photos. Also removed the bonnet actuators and associated lines as well as the Mercruiser tilt/trim hydropak from the trunk. Here are the replacements:



Open or shut will take about 1/4 of a minute but it has switch stops at each end which cures a couple issues. I'll be able to hit the switch to open and walk away for instance, and when it shuts it will resist lifting from aero effects which will be a plus.

As you can see it does not have the spherical ends so I will have to build that into the mounts. I have the bearings ordered. Once these are installed and tested I plan to order a set for the wing as well.

Jim

[BlownMGB-V8]

Two jobs yesterday. First I wire brushed the sockets and plug-ins for the bumper assembly, checked the fit and painted them with black rustoleum. When we went to remove the bumper rust had built up and made that difficult so that's to be prevented in the future.



If I can find Waxoyl at the box store I'll spray that down the sockets into the square tube, and I'm going to apply a generous coating of anti-sieze as well. Hopefully all that will do the trick for next time. Otherwise the fit is just fine.




Job 2 was getting started on building the mufflers. Using holesaws I made up 4 spacer washers which I'll weld about an inch inboard of the ends of the perforated tubes. Then using a hammer I belled one end of the outside tube inwards so that it fits the 2-1/4" tubing and did the other one today. Better job the second time, blacksmithing takes practice and patience. Takes quite a bit of hammer work but makes a nice transition.If not quite up to factory standards, it's at least a thicker material and should be more durable.



I expect they form cherry bomb case ends in a press with special dies. I will probably cut two more spacer washers for the outlet ends and weld those shut, though I do wish I could come up with an acceptable means of making it removable with common tools. On bike mufflers they just use a slip fit with retaining screws. I'll have to give it some thought, I don't think I have any suitable stainless for doing that but maybe I could buy a piece of 303 round bar and cut them out. That would probably be best, I could put a lip on it and notches for removal. Nope, too expensive, that stuff is almost $300 a foot. Maybe Ken has something useful lying around which probably means I'm back to holesaws again. Not a light proposition for 5/8" thick plate. He could waterjet cut them for me though... Still probably a C note for that. I'll check with him tomorrow, I don't have any usable scraps lying around and Alro doesn't have any drops.



Jim

[BlownMGB-V8]

The bumper slid in just like butter. Then of course I had to go and overtighten one of the bolts and probably collapsed the spacer tube a little so it will need work next time it comes apart but I can let that go for now.



My usual sources were not much help on material to make the donuts for the removable end of the mufflers so it seems there's more blacksmithing in my future. Here's a piece of surplus 3/8 x 3/4 stainless bar that I've begun bending into a circle. I will have to heat it to get it round but after the ends are welded together it can go in the lathe to cut the step that will go inside the 3" tube.



The V coupler flange is 3" diameter so it makes a decent gage. I won't be able to cold bend the bar all the way around but with heat, hammer and anvil I expect to prevail eventually.



After that I will add screws to hold it together and notches to punch it apart. Still thinking about what type of screws to use. Kinda leaning towards brass a little.

Jim

[BlownMGB-V8]

Made up my spacer donuts yesterday, which will allow me to remove the exit end of the mufflers to repack them. After forming the 3/8" strap into rough circles I welded the ends shut, allowing a semi-generous kerf for the filler:



Next between the vise and the hydraulic press I made 'em mostly round, using a 2" chunk of round bar and a V block. The fit on the tube is loose but I can fill that with weld:



Next it went in the lathe to cut the OD and I got a good result there, just what I was looking for. I cut the 60 degree front ends which need trimmed to length and mated to the collectors. Some careful measuring will be needed to make sure the rear clamp is in the right place, weld that all up and it'll be time to wrap and pack.



I've seen people use masking tape on the packing, which works but will burn off. Glass tape might be better. I found some teflon coated glass fabric tape on amazon that should work quite well.

Jim

[MGBV8]

Or thin stainless wire?

[BlownMGB-V8]

Good suggestion. The work continues with decent progress though not much to show. The header muffler bodies are now in place and connected up, they need the sensor bungs and the end plug and to be packed.





The length is going to be close and as they are longer than the old ones I hope the extra length and the packing will offset the tendency of the stainless to ring. I'll be cramming in as much of the packing as I can get to fit. Part of the work on the rear of the system is already done so that should go rather quickly but I have to re-route the fuel lines before they can go in.



I'm about close enough for a checklist. After the exhaust is finished and the grille is installed:

-Complete the fuel filler neck.
-Install the bonnet and make mounts for the electric hood actuators. Align bonnet and trim tinwork to match.Install wiring, change switch to standard (not MO) toggle switch.
-Close up AC system and charge with oil.
-Make fuel rails, connect lines and install FPR.
-Make standoff to locate bug catcher above fuel rails.
-Kerf and weld cracks in bug catcher, grind, buff and polish. Install that and throttle body. Connect linkages and wiring. Extend and connect injector wiring.
-Complete detail work.
-Reprogram ECU.

I think that's most of it.

Jim

[BlownMGB-V8]

I hope to pack the mufflers today. some screws and taps need to come in before I can install them for the last time, close up the rockers and install the sensors but I can pretty much get everything done except the caps. Here are the sensor bungs and let me tell you, starting the tap correctly for chasing the threads after welding is not the easiest task.



These caps were actually pretty easy once I had the parts assembled. I'll probably use a high temp silicone on them at final assembly. The screws won't actually clamp the tube to the plug, as much as hold it in position using the sides of the heads. That way there is less of the head projecting into the clearance areas.



Jim

[MGBV8]

Here are the sensor bungs and let me tell you, starting the tap correctly for chasing the threads after welding is not the easiest task.

Hmm, could you have welded them up with a big bolt or an old sensor threaded in?

[BlownMGB-V8]

Not sure that's a good idea. There is warpage and stainless is real bad to gall and seize. It might work but could also stick and that'd be bad, especially if you broke off a sensor. Part of the problem is that my M-18 tap, though of fine quality tool steel is also a plug tap. Which isn't problem usually but in this stainless it's way too easy to get it started crooked and then you're pretty well screwed. I was using standard brown cutting oil but I'm thinking that lubricating the tap with cutting wax like you use for band saws and carbide die grinder bits might have worked better. If I'd had more than 4 of them to do I'd have tried that.

I got the mufflers packed and it went smoothly. Photos of that tomorrow. Just reclaimed some trunk space and noted that my exhaust tubing is the same size as my gas tank filler neck so that helps. Also have to do seat belts. My thicker webbing came in and I've cut the pieces and stitched up one end but I'll need to increase the top side tension to get even stitches. That can come later.

Jim

[BlownMGB-V8]

So the first shot below shows one of the cores wrapped in the carbon fiber fire blanket and then spiral wrapped with the teflon tape, leaving gaps where the blanket poofed out (technical term) which may give it varying silencing characteristics. I'm going to claim that is a proprietary layering method.



As you can see here, the poofed segment contacts the outer casing while the taped segment eases insertion into the casing. The ends slip into the stubs for a seamless (literally) transition at each end.



Here you see the stub on the end cap.



Fortunately my taps and screws came from McMasterCarr last night and I found a tube of red high temp silicone in the cabinet so I should be able to do the final install of the header muffs today. Hope so anyway.



I got the fuel return line re-routed yesterday (also the VSS sensor wires) and should get the fuel supply line done today. Then the vent line. That will clear the way for the rear half of the exhaust system so another couple of days should do that. Then it's on to the bonnet and perhaps the filler neck.

Jim

[BlownMGB-V8]

Here's the end plug glued and screwed.



The glue is red high temp gasket maker and I found that it cleans up pretty easily using paint thinner.



The screws are a stainless round headed torks plus from McMasterCarr, said to provide extra driving force, anti-seize applied of course. I used the copper based one here.

Jim

[BlownMGB-V8]

Nearly finished with the driver's side now, and not a great photo but light was flaring in from the skylight in the shop so it was the best I could do on short notice.



I'll probably move the resonator forward a couple inches to clean it up at the rear but other than that the side is done. Still have to install the tip and the cheese grater rocker panel, and after the bonnet is properly fitted I have plans to install splash panels between the headers and the front tires but that can come later. After all I've put that part of for over 4 decades now, I think it can wait a few more months.

Jim

[BlownMGB-V8]

I moved the resonator forward 3" which gives me room for an exhaust tip and gets the coupler under the bodywork. Fitted and tacked the parts for the other side and hope to finish that today.

Note of interest, if you build a stainless exhaust and do the work yourself, make sure you provide yourself with a safe air supply under your welding hood. Chromium and Nickel fumes are toxic and while you can tolerate light exposure you will start feeling bad before you realize what you've done. I know better, not my first time around but you tend to forget these things you know? Make sure you deal with it before you realize that you aren't feeling like your normal self. Happily symptoms tend to clear in a few days so it's almost like a mild cold but heavy metals do tend to take longer to get rid of so it's best avoided in the first place.

For the most basic of systems, provided your shop air is free of things like compressor oil a simple metered tube and diffuser inside the helmet is an acceptable fast remedy. As a rule I don't advise breathing shop air but it's cleaner than welding smoke.

Jim

[BlownMGB-V8]

Not the best shots, but except for the vented panels the exhaust is done.



I plan to button it up today and put the wheels back on, then lower it back onto the tires and prep for the bonnet fitment.



That could be challenging. A little back story here. When I created the current one piece bonnet it was with fresh sheet metal and an intent to do the job right. I got it all fitted up then disassembled it for paint but when I went to reassemble I was never able to get it to fit quite right. My mission now is to find out why and correct that problem. For the past couple of decades the beltline has never been right and the assembly sat high in the front. At one point I closed up the gap at the mating line so that's another issue I'll have to deal with, and there's also some warpage that was created by poor welding strategies at the time. I should be able to correct all of that but can't say what it'll do to the paint. That's another job that will eventually have to be re-done. Oh well, the car's never been straight the whole time I've owned it. I'll just have to do the best I can, same as always.

Jim

[BlownMGB-V8]

Wheels are back on and it's starting to look like a car again thankfully, if somewhat dirty. Oh well. Fitting the bonnet and trying to get it down in the front so the beltline is straight. So far I've trimmed out metal from the underside of the hood and enlarged the cutout to make room for the alternator. It pokes through a half inch or so. That will be more by the time I'm done but I was able to follow the curve of my black flames so it blends in pretty well I think.



The next step involves some bending. It seems that at some point the passenger's side got pranged a bit. Dan was there at the time I'm sure he will remember. Anyway it's never gotten properly straightened back out and it's causing the beltline to be high in the front by about 3/4" at this point. I can't correct it any more by shifting things around. Below if you look carefully you can see some evidence of buckling. It's not much, but projected forwards it's enough to cause trouble.



So, I've chained the car to the floor. I have a couple of cheap Black&Decker laser levels I've used for wheel alignment so today's task is to stick those to the doors and project them forwards along the beltline for references at the front corners, and then I can try jacking that corner down. Maybe I'll be able to pull it in.

Of course if I succeed that means the big stainless stringer on that side will no longer fit as the holes will be moved forward, perhaps about 1/8" or so. The remedy is more blacksmithery naturally. I'll have to heat and beat the stringer to stretch it out so the holes line up and then grind and polish it again. It's a bit of work, but that beltline has bugged me for decades now. It's time to fix it.

Jim

[BlownMGB-V8]

It's better than it was and I think some times that's all you can hope for. The sad truth is that this particular Hot Wheels car has just been sky'd off the ramp too many times to ever hope to be perfectly straight again. That'd take a redo with a different car that was straight to begin with and I really can't see me doing that. However, no MGB was ever perfectly straight even right out of the factory and you can bet I'm gonna use that. So here are a few shots of the process. I set up my lasers  to line up with the doors and if you look close enough you can see the lines and the center dot. I've got to work with what I have and this is as close as I can get it. Once the lift struts are on they may be able to pull the bonnet down slightly more. If cost were no object of course I could have the bonnet made up in carbon fiber with a perfect fit but that will have to wait for the brand new Heritage body tub that I'm never going to buy. For now this will do. Time for some reassembly.

Jim