GETTING INTO GEAR

One thing about having this race car is I am delving into areas I've never ventured before. Case in point, gearbox rebuild. Never really needed this on my street Spitfire, I simply swapped out the gearbox or diff for another. Not sure what compelled me to tackle it but I am very glad I did.

Early on, I broke the tailshaft on the Toledo gearbox that was in the race car when I bought it. I was given I donor 3 sync gearbox and promptly tore it down. This gave me a bit of insight into the workings of a gearbox. That and a bunch of U-TUBE videos. After the motor blew, I had the gearbox out and noticed a bit of wobble in the input shaft so I decided to tear it down. My hunch was correct, the front bearing was bad so I ordered a rebuild kit from RIMMER BROTHERS.

The problem for me is the Toledo box is not the same as a four sync Spitfire three rail gearbox. Or let me put it this way, the Toledo "DG" gearbox case I have and the gears in it are not the same. I am still trying to figure out this box. The input shaft has 19 teeth and the syncro rings are smaller that the Spitfire "FK" boxes I have. The Spitfire FK boxes have 16 teeth and the syncro rings are larger. Also, the caged needle bearing in the DG box is bigger as is the mainsheet tip. It is .62" versus .50 for the FK box.


Most of the input shafts I have, the gear is quite worn. The tip on the mainsheet of the Toledo box is damaged. One of the FK mainsheet tips is very worn and one is pitted, another has a chip out of it. I was hoping to pick the best of them bunch to rebuild one solid gearbox. All this has been a frustrating trying to find commonality among these gearboxes I have, it seems there is always one piece of the puzzle wrong.

I will say after tearing down five gearboxes, they don't seem to be the mess of spagehtti they looked like to me at first. I now recognize the parts, what they do and which order they are in.  The rebuild of one of the FK boxes when very smooth.

 A couple tips, get some 1/2" or so ALL THREAD rod and put a nut and large washer on one end, as you remove the gears and such, put them on the rod to keep them in proper order and facing the correct way. Them place another washer and nut on the other end to keep them in place till rebuild time.

Another tip is to put the syncro units in a plastic baggie when removing the springs and ball bearings. This will keep them from flying all over the workshop. Also, thick grease is you friend during the rebuild. It will keep parts like the split thrust washer in place as well as the needle bearings in the layshaft. It also held the springs and ball bearings in place when putting the syncro unit back together.

And finally, put some string in the case then, set in the laygear. This will help to lift it in place to insert the layshaft after the mainshaftand gears have been installed.

Getting up to speed

Like so many Blogs, I realized this one has gone by the wayside. I haven't posted an update in ages and so much has happened. My last posting was the Dyno day. Since then, I have had two race weekends and have not blogged on them.
The first race weekend ended with me cracking the tail shaft on the gearbox. I did the Friday "test and tune" day with no incidents, Ran the practice race and qualifying for Saturday's race but when I got back to the pits, she was leaking a lot of oil from the gearbox and I decided to pack it in.

Not sure how or why the tail shaft cracked but ever since I got her, when I got her up to 70 mph or so, I felt a bad rumble that I think/though was coming from the diff. I still have yet to tack down the source.

The next race weekend, the plan was to conserve the car so I could finish the two races I still needed to get my SCCA competition license. I sat out Saturday's practice and qualifying race. I started at the back of the pack and did manage to finish. GREAT! one more race to get in the books and I get my "hard card". Again, on Sunday, I sat out the practice and qualifying race and again started at the back of the pack. This time, accompanied by two other Triumph Spitfire's. Another '62 and a '64, both driven by good friends of mine. Again, the plan was to conserve the car and just finish the race.

All went to plan till I rounded turn one going pretty much flat out, scrubbed some speed, downshifted into second and I felt a strong judder. I immediately took it out of gear and looked for a place to park it. I put it back into gear and limp it to the run off road at the beginning of turn three. I got towed to the garage and we pushed her up in the trailer.

Now that she's back home, I've pulled the gearbox and drained the oil. Gearbox oil looked good but I did notice the input shaft appears to be bent. I'll need to look into this further. Also, I pulled the driveshaft out and was going to have it balanced but decided to swap it for a Spitfire driveshaft as it has a driveshaft from a MG in her. The MG shaft is much bigger in diameter. The engine I have really doesn't need a shaft that large. Or so I think...

Dyno soar or Dyno sore...

I realized (again) I haven't posted anything in some time. I took her to the dyno-shop, Colvin Automotive here in Austin to speed up the tuning. It was $$$ well spent. Pretty much the entire time was spent on dialing in the DCOE. The rest was in good order.

By swapping jets we found 9 more horsepower at the wheel. I had her running a bit too lean at idle and progression and we fixed that as well.

She sounds strong and I can't wait to get her on the track this weekend.
I post the jet setting for the 45DCOE later as well as the dyno sheets.

Don

Some time ago, I came into a stash of spark plugs. I must have over a hundred NGK, Champion and Bosch plugs. All new in their little boxes just waiting their turn to ignite some fuel and burn it down the track.

In preparing to take this car to a rolling road or dyno as it's also know as, I started sorting out some different plugs I'd like to try, mostly various heat ranges as well as brands. When I got the car, it had NGK B6HS plugs in it. I've learned more about spark plugs in the last week than I had my entire life. 

Everything from heat range and why it matters to materials, indexing and reach. 

And reach is what this blog entry is to be about. Reach and why it matters. When I first pulled the plugs out, I must admit I thought they looked short. This being a full blown race car, I thought there must be some reason have yet to learn. I looked through my stash of spark plugs and saw I had quite a few NGK B7H, B8H and B9H plugs. Quick search of NGK's website and I found B means 14mm / 13/16” hex size, 7, 8, 9 is the heat range and H is the 12.7mm (1/2”) thread reach and S is Standard Type (2.5mm Center Electrode) Great, I thought. I have a few "colder" plugs I could try out on the dyno.

Then I began to think about REACH. The 1/2" reach just seemed too short. I took three different plugs and put them in a Spitfire head I had on the shelf. You can see in the photo, examples of REACH.

In the #1 cylinder is a NGK B-7H with the same reach as a B-6HS which is what was in the engine when I got it.

In #2 is a NGK BP6HS which means it is a Projecting Insulator Type thus the P and the S at the end means it is one unit hotter than a 6 but not a 5. A bit confusing but more on that later. 

Next, in #3 is a NGK BPR6ES - So B=13/16” hex, P = Projecting Insulator, R = Resistor Type, 6 = heat range, E =  3/4” thread reach, S = a bit hotter than a 6 but not as hot as a five. 

And #4 cylinder is empty. 

Here is a pic of the three different plugs

And here is the head that came with the car as well as the plugs.

Seems I need to change to the "E" 3/4" reach plugs as from the Factory.

A little help from my friends

So this past weekend found me at Harris Hills Road track just south of Austin, TX. It was a great "test and tune" day I have been needing. It was really a rush to go WOT and not worry about the neighbors calling the cops! Harris Hills Road is a great track too.

On track at Harris Hills Road

I have to thank all those that helped me get there, and those that helped me get around there.
So in no particular order I want to thank Brenda, Rick, Fernando, Robert, Dave, Bill and Rod.
I couldn't have done it without all of you.

Bill adjusting the timing

So, what did we accomplish? After unloading and suiting up, I took her out for two laps. I realized I'd left my "safety" pins in the fire system and thought it might be a good idea to pit and remove those. I have yet to get a routine down. Sputtering in, Dave suggested we "adjust something", not just go back out and burn expensive fuel! He suggested adjusting timing or jetting. So I asked Bill to get a wrench and the stubby screwdriver and let's move the timing one way or the other. Turns out Bill retarded the timing and I went back out. She seem to run a little better so after two laps I came back in and had him retard it a few degrees more. She ran a bit better so we retarded it a few degrees more.

This time it seemed to get a bit worse so I pitted and had Bill move it back and went back out for a few more laps. She still had no top end. I could get to around 5K rpm if I feathered the throttle but if I just put my foot to the floor she would bog down. At this point, I came back in and had Bill change the main jets from 130's to 140's. 

Trying to figure out what we figured out...

One thing I should mention is after about the second or third run, Bill and Dave noticed fuel leak (again) from between the carb and the manifold. Bill tried to tighten the bolts but it still was leaking. I'd put a new anti-vibration mount and rubber washers but it still leaked. I'll tackle this issue in another post but I think a little porting is in order. Also, Dave and Bill notice an oil leak. Two actually, one near the front of the engine and one towards the rear. So with the fuel leak and the oil leaks, Dave thought it best if put her back on the trailer. He did said go out for three more laps which I promptly did!

This is never a good sign

Once home, I put her on jack stands and crawled under her. The leak from the from appears to be the oil cooler hoses needing tightening. The rear leak looks like gearbox, as oil is dripping from the "weep" hole in the bell housing. I recall the bottom bolt in the bell housing had some blue RTV on it and I pulled it and put some gasket sealer on it. I don't recall if it had a copper washer on it but after finding the misplaced copper washer on the rear engine oil seal, I should have checked. A rebuilt kit is on it's way and this weekend will find me pulling the gearbox out.

Running much better than where we started

The oil pan lip was dry as was the timing cover and when I checked the oil level on the dipstick, it was at the full mark.  I was quite happy to see that! I pulled the carb off and I found a couple things that might be the cause of the leak. I bought this Weber 45 DCOE back in around 1987 or 88, I was living in Daytona Beach at the time. It has seen many, many miles. I noticed the mounting holes to be a bit wallowed out. Also, when I put the anti-vibration mount on the manifold, it really doesn't line up with the ports.
I'll look into that this weekend as well.

A little help from my friends

And again, thanks for all the help from my friends!!!!

Pushing a bit too far

So I order new shorter pushrods from SMITH BROTHERS PUSHRODS. Like a lot of the custom parts in the motor they are truly works of art I hate to have to cover up. Form and Function I guess.
None the less, they worked perfectly. She fired up and idled right down.

There was stil a bit of a misfire and after some fiddling and fussing it appears the Pertronix unit gave up the ghost. A quick call to my good friend Mike McPhail to see if he had a replacement unit. He did as well as a new Pertronix distributor. My thoughts were go with the new distributor to rule out and dizzy wear that might be in the old one. I must say though, the "old" one sure looked new.

So now with new shorter pushrods and a new dizzy, I fired her up and she roared back to life. She still seemed a bit rough at idle. I then turned my thoughts the possibility I might have an air leak somewhere. I sprayed some WD40 around the intake/exhaust manifold gasket, no change. Next, I thought about the leather seals on the throttle shaft of my DCOE. As this carb had been sitting on my shelf for ten plus years and the seals were NOT part of the rebuild kit just maybe they were dried and leaking. I took a bottle of 90 weight gear oil and carefully poured some oil around the shaft ends and worked the throttle back and forth. Not sure but it sure seemed like that did the trick!

She idled smooth again and seems happy now. Time will tell.

Pushing me too far

How this car ever ran is beyond me! The pushrods are too long. The valves can't close all the way, the car should never have been able to run. Yet it did...
It's always funny to me how life plays little tricks on us. Checking to see if we are paying attention or  just trying to "phone it in". Case in point, these pushrods. I remember popping the valve cover off and looking at the rocker arms. I noticed the adjustment screws were all the way out. So, I remember trying to see if there was any valve lash, and, on number one rocker, there was. On the firewall, someone had written in sharpie, .020 INT and .020 EX. I thought this was kinda cool but also took it to mean, someone had checked the clearance.

Since #1 did have some play, I just went on looking at other stuff, put the valve cover back on and got her to fire up and run "screaming demon". Just kind of back-burnnered the valve lash as I had much bigger problems like a leaking fuel cell and an upcoming race.

SO fast forward to now, after tearing into this motor to fix some of the issues that crept up on me. I button her back up and now mind you my method for removing and replacing the rocker shaft is to evenly loosen the four nuts that hold it down. Been doing it this way for thirty years and have never bent a rocker shaft. The idea is if you do not disturb the adjustment screws, when you torque it back down, it she have the same clearance. SHOULD

When I took the rocker shaft off and the pushrods out, I checked the lifters and noticed four of them where a bit "scuffed" so I replaced them. after assembling all the bits and pieces of the motor back together, I fitted a new Payden head gasket and torqued it down to 50ft/lbs. Next I put the pushrods back in and torqued down the rocker shaft. Filled her with oil, water in the radiator, fuel in the cell and tried to start her up.

She coughed snorted and blew fire out the carbs, Good thing Brenda wasn't out there for that. It was kinda cool looking but also a bit scary to see fire burning in a carb throat in the garage. So, I fought it for about the next three hours and played with the timing and idle adjustment, fuel pressure and did get her to sort of run but really really rough.

Enough for one weekend and it would be a week before I could get back to her. During the week I thought about it more and started to think more about those pushrods. I remember thinking they looked like stock rods. And I remembered how the adjustment screws were all the way out.  I had a set of shortened pushrods, well I had seven because one got bent because a lifter stuck in the bore on a new rebuild I did years ago. That's another story. Anyway, I figured the number one valve had clearance, at least some, so I'd leave it in and replace the others with this set of seven.

Dropped them in, adjusted lash, which now I was able to do. and...
SHE FIRED RIGHT UP!!! Idles great, revs up nice and she is roaring again.

but what I don't understand is, the old pushrods didn't grow. How is it that this motor ever ran to begin with? Yes, I did replace the head gasket but it is a stock item. Best I can tell so was the one I took off. It can't be .050" thicker. There were no shims under the rocker pedestals. I never changed the rocker adjustment screws, Hell, I couldn't have even if I had wanted to because they were backed all the way out to begin with.

So I bought an adjustable pushrod and need to check the rocker geometry. Then, I will order a set os shorter pushrods.