Budget street legal rail (re)build (WARNING: pic heavy)

[Marc]

If you find cracks between the seats, they're not cause to discard a head. You might not want to sink much money in one like that, but in the immortal words of Pa Kettle "it don't hurt the runnin' of it none".
Even heads with cracks from the valve seat to the plug threads can be run, but it the crack has propagated up by more than a couple of threads it's starting to get pretty sketchy. It's possible to install a short Time Sert backwards (with the flange countersunk into the chamber side) to milk all the miles you can out of a cracked head.

As I said before, the early U cases were cast from the same low-density alloy as the infamous `68/`69 H5 and B5 cases so they're not a good foundation for a quality build. If steel inserts haven't been installed between the head studs and the case you should probably see if you can fix the plug threads with the head on first, rather than take a chance of unthreading the studs from the case - that alloy doesn't take kindly to removal of the studs. If you must remove the head, soak the head nuts for a day or so before you put a wrench to them and try not to disturb the studs.

If you're experienced with sparkplug Time Serts you'll know that their proper installation includes using a double-row cutter which both spot faces the gasket surface and counterbores the top of the threads so that the flange on the insert will sit below flush - peer down at the top of the threads - is there a visible counterbore?

Any reader unfamiliar with the process should watch the video at the page which I linked above....http://www.mechanicstoolsandbits.com/ti ... 21_54.html
Just below the video they reference their "Big-Sert" (last-ditch) system that hogs the head out to 18x1.5mm. I've never personally resorted to that one, but it exists...

Once upon a time I was obsessive about sparkplug indexing - seems like a good idea in theory, but to be honest I never found it to have any discernible performance advantage (it just "looks better") ...I wouldn't lose any sleep over that on a stocker.

[GoMopar440]

The second coat of grey paint on the shroud was a little better. Good enough for mock up. First thing I did today was to assemble all the upper tin work on the engine. I started with the cylinder top tins, getting them seated properly and then bolting them to the heads.


The shroud was set on the engine and I found a couple of places the bottom edge was getting stuck on the right cylinder tin. A few seconds with the cut off wheel on the angle grinder and I was able to trim the edge of the corner. I also had to widen the notches on the cylinder tins. One cut on the front edge and the other on the rear edge. I only needed to widen the slots the width of the cutting wheel (1/16"). After that the shroud sat nicely down onto the engine and into the cylinder tins.


Next I attached the cooling fan onto the back of the alternator. It's a new chinese fan, so the quality was about what I expected. It was running out about 1/8" so I tweaked it a bit by hand to get it to run closer to being true. It doesn't hit the shroud anywhere at all, so that's good enough for me. I had to loosen the two lower screws holding the shroud in place to be able to fit the cooling fan inside the shroud. Once I had a little wiggle room everything was finally able to fall into it's proper place.


The second 34PICT-3 carb still needed it's front mounting hole offset by .150, moving it closer toward the center of the venturi. I also milled clearance on the outer front side of the carb so I would have room for the hold down nut. While I had it in hand I also installed the new throttle shaft seals I got from Germany. I had already replaced the first PICT carb's throttle shaft seals a few months ago, so now both have snug fitting throttle shafts. Both carbs still need to be put back together, but they're fine as is for mock up purposes.


With the upper tinware and the carbs now fitted I turned my attention towards the next eyesore, the oil pump cover. When I was cleaning around it, I was finding slivers of orange RTV at the seams. When I got the cover off I found RTV had filled the circular groove on the outer face of the oil pump. I spent some time carefully getting rid of all traces of the RTV and the old paper gasket from the oil pump and the steel pump cover. The pump cover got cleaned up and then sanded to remove the sharp edges. I also sand blasted the outside and sides of the cover to blend in the sanding marks. The inner face of the cover was slightly scored from the pump gears so I put progressively finer grits of sand paper on the flat top of my mill vise so I could sand out most of the gear tracks. Now there are just a faint trace of the gear tracks left behind. They don't catch my finger nail anymore so that's good enough. I'll eventually be replacing the oil pump cover with one with a single hose outlet on it like the one on my other engine. I sprayed the cover with carb cleaner (all I had handy) to clean it up and taped off the back side. I sprayed it with gloss black and hung it up over the heater to dry. The nuts were wire wheeled and painted black as well. They are only going back on temporarily since I'll need to replace them when I swap out the pump cover. All four of these nuts where missing the rubber o-rings on their backs/bottoms. I just need these original parts to keep dirt and crap from getting into the oil pump and engine while I'm still working on it.

[Leatherneck]

Good looking tin, lots of holes though.

[GoMopar440]

I haven't filled them up yet since it's just in the mock up stage at this point. I'll be closing up any unused holes and sealing up the gaps at the edges. That should keep all the air going where it will do the most good.

I don't like how the paint turned out of the main shroud so I'll be stripping that back down to bare metal. After all the unused holes are filled/patched, it will get smoothed over with a skim coat of filler and repainted. Probably with a gunmetal grey shade of Cerakote (SP?).

[GoMopar440]

I was out running errands most of the day so I didn't get much time to work out in the barn today. I did go out there for a few minutes this evening and pulled the head with the messed up insert off the engine so I could take a look inside it. The first thing I noticed as I was taking it apart was the thread repair insert came out with the spark plug.



Other than that not necessarily unexpected hiccup with the insert, taking the head off was a non event. I don't have a valve spring compressor tool so I didn't get a chance to look at the valve seats and valve faces yet. However as I cleaned the black gunk out of the chambers, I found a couple of cracks going from the valve seats to the spark plug holes on both sides.
* This is the chamber with the good spark plug threads. (1 crack) *


* And this is the chamber with the bad spark plug threads. (1 definite crack and at least 2 more possible cracks)*


Is this head fixable, and if so, is it cost effective to do so? Or should I just plan on replacing the head?

[GoMopar440]

Umm... I may be changing direction with the whole carb setup quite a bit sooner than planned. I just found an auction for a brand new 40 IDF clone on Ebay while surfing around. It was listed with a BIN price of 89.10 plus 35.50 shipping. Orders over $80 currently get a $3 discount through that vendor, so the total was $121.60 delivered to my door. To me it's worth taking a chance on it for that price.

It appears to be a 24 hour sale auction with just under 20 hours left on it. There's still more than 10 of them available according to the auction. It sounds and looks like it's identical to the chinese IDF clones previously offered from $135-175 each. I'll post what jetting is in it and any other interesting notes I find out about it when it gets here. Get 'em while they're hot!

http://www.ebay.com/itm/151894855573?_t ... EBIDX%3AIT

[Leatherneck]

Could work ok could be a nice paper weight.

[Marc]

...Is this head fixable, and if so, is it cost effective to do so? Or should I just plan on replacing the head?

I've run worse ...as I said above, if you can get the plug to stay in it'll get you down the road for a long time like this. If there're cracks from the threads to both the intake & exhaust seats you should probably give up on it, though. Small cracks between the seats won't hurt anything.

To "fix" it by welding it up, the valve seat(s) should be removed, and the head machined to shrink in new ones afterwards. I've seen a lot of welded-rebuilt heads that cracked again; IMO it's not worth doing for a stock head. One that had a bunch of money in it (e.g. oversize seats, porting) would be another matter.

Another spot to check for cracks is the roof of the ports (esp. exhaust). Look 'twixt the finnage for dark lines. An exhaust port crack may have no symptoms, or at worst nothing more than slight leakage that can be mistaken for an exhaust flange leak. Again, not cause for scrapping the head, just a reason not to sink any time/money into it. A cracked intake port, while rare, can haunt you with mysterious idle problems.

Back in the`60s it was said that Autolite plugs should be avoided, dogma was that their threads weren't as well-formed as other brands and could eventually wear out the threads in the head. I'm not sayin' there was any truth to that but to this day I won't use 'em (or Champions) in a VW.

My first choice is NGK (B5HS or the cooler B6HS). Bosch W8AC, Beru 14-8A, and Nippondenso W16ES-U or the cooler W20ES-U have given me good results too. I DO NOT recommend platinum electrodes. It's getting hard to find non-resistor plugs anymore, and since the VW plug ends contain their own 1KΩ resistors, resistor plugs are not desirable (although they'll usually work). One could also remove the resistor (it's secured with a little hairspring) and replace it with a length of brazing rod.

[GoMopar440]

My last reply didn't post for some reason and I really don't want to type all that over again... so I'll just summarize a bit.

NGK and Bosch are my usual "go-to" brands for spark plugs. Thanks for those plug numbers as they will definitely help.

This head is going to be used on my stockish single relief backup engine while I'm upgrading the dual relief engine. I'll probably go ahead and shove the plug and insert back in the hole with a bit of JB weld to help lock it in place. (unless that will hamper the conductivity of the spark plug?) I just need it to get me by for a little while as the other engine is being modded. I don't plan on keeping the Autolite plugs or this cracked head casting, so there's not much left to loose at this point. Since this is just a plain jane stock DP head I don't want to spend any more on it than I absolutely have to. I'm still going to be looking for a good used stock head to replace it in the meantime though. I'll swap this cracked head out once I locate a good replacement for it.

[Marc]

Even with some JBWeld in the threads there still should be ample metal-to-metal contact to the plug to fire. Might reduce the thermalconductivity a bit but that shouldn't matter too much. Put a new plug in there so you won't have to disturb it for a long time and run it.

You're probably aware that Bosch and NGK heat range numbers run in opposite directions. W8AC and B5HS are the normal choice; W7AC and B6HS are a step cooler, shouldn't need those for this project.

[GoMopar440]

Random thought here: Over cooling might be a real possibility during the winter up here. I've bought a power pulley for the engine but I think I may save it to try out on the engine for when it gets really cold outside. The reduced cooling from using the smaller pulley might work in my favor when I want to drive it on those real chilly days. My long term goal is to make it a daily driver and then enclose the cab and add heat so I can use it year round. Driving around on the snow and ice is fun enough in my little truck. I can only imagine what it would be like to drive around in the rail on that stuff.

[GoMopar440]

I was out in the barn for a few minutes tonight so I pulled the #4 cylinder off and cleaned it up. There was one paper gasket between the cylinder base and the case. Inside the cylinder is a ridge at the top of the bore but it is in good shape other wise. I'll break out the snap gauges later and measure a few different points inside the cylinder to check it to make sure it's still round.

Then I cleaned off the top of the piston until I could read the numbers stamped in it. It was marked with "STD" and an arrow pointing towards the flywheel, but I couldn't make out the other numbers on it. I measured the piston just above the top ring and got 85.02mm. Does that sound right for a 1600?

[Piledriver]

Pistons head is always a bit smaller than bore as it expands far more.

"std" could mean 77mm (1300) or 83mm (1500) ... but most likely 85.5mm.

Would be best to measure the cylinder towards the bottom, below ring wear area, or the piston about even with the middle of the pin but 90 degrees out.
(top<>bottom).

If you are replacing them don't worry about it. (except to check out the new parts)

[Marc]

I'd expect to find a 1600 piston (nominal 85.5mm bore) stamped with something just under, e.g. 85.46.
Have never seen an 85.02, there's no standard or overbore that size that I'm aware of...I'm going to assume you've misread or mis-typed that number

An actual ridge (not just carbon buildup) will be a problem if you use the cylinder again without the paper gasket. I'd get a set of .010" steel shims and use them (with a light coating of RTV) but if you can't get any at least use the paper rings.
Push the compression rings in and see how thick of a feeler gauge you can slip in alongside them without forcing. If it's over .004" the pistons are pretty shot - not really worth the time to clean/hone/rering...but they'd still run for a while if you did.
Remove the carbon, run a dingleberry glazebreaker through 'em to establish a cross-hatch, and throw on some cheap cast-iron rings (such as Grants). Measure the widths, though, because there exist 1.5 & 2mm compression and 4, 4.75 & 5mm oil. German Mahles once used a 1.75/2/5, those can be hard to find rings for.

[GoMopar440]

It's not a miss-type. I rechecked it a couple of times since I was expecting it to be closer to 85.5mm. The piston does measure at 85.02 above the top ring. I just went back out to the barn and checked it again. Normally I check and reset the zero on my digital calipers every time before I use them. I'm positive I checked and reset it when I took those measurements before, but I did it again just to be safe.


I rechecked the piston OD and got just about the same measurement as last time.


I haven't cleaned out the ridge of carbon above the top ring in the cylinder yet, but I measured it anyway just to see how close it was to the piston. Allowing for the carbon build up, this measurement is a lot closer to what I was expecting on a stock 1600 engine.


I tried to get a close up of the size stamping on the piston. The numbers are only half formed, but from what I can see, they look like they might read 85.46.


There is this mark on the top of the piston as well. Maybe a makers mark?


I inspected the top edge of the piston and noticed the surface wasn't smooth like the piston top and the skirt. This could be a sign of wear that is causing the OD reading I've been getting. If so, I may want to look at a getting new set of pistons and liners.


What do you guys think? Is this a sign that the pistons have been wearing too much to use them? I never did a compression test before I pulled this engine out of the T3, but it did feel a bit anemic compared to the 1600 that's in my rail now.

I have a 3 arm cylinder hone I can use to freshen up the cross hatch if I decide to reuse these pistons and cylinders. The carbon will get removed with some cleaner and a scrubby pad first so I don't gum up the hone stones.