Lhead build

I recently rebuilt the Lhead from my 3A. I've been working on it for a couple months during any free time I've had. The engine is back together, but still have a few more things to bolt on, and still need to put it back in the 3A. I figured I'd post some pics of the progress. I'll add more pictures of the whole process when I get them from my camera (these are cell phone pics).

Bored .030", installed new pistons, bearings, rings, oil pump, hardened valve seats


Installed valves, new springs, etc.


cleaned up the head and painted it


blasted my homemade header/intake and painted it with VHT paint


and a pic with more parts installed, but not a pic of it's current state. The motor is basically complete now, only thing left is bolting on the flywheel and a new (not bent) crank pulley...but I don't have pics of it at that point.


I'm currently rebuilding the transmission, then will throw all the drivetrain back in the jeep. Anyone know if it's possible to install the Lhead, transmission, and transfer case all as one unit? The tub is still on the jeep, but the fenders, grille, and radiator are all off. Thoughts on whether is easier to install as one unit (if possible) or to install the motor alone, then muscle the tranny and trans case in place afterward? In the past I've either taken the tub off, or laid in the dirt to muscle the tranny in place...hoping it might be easier to install as one unit.

 

looks nice, I like the header/intake

 

Looks great!! Not sure where valve #9 came from though R)R) If you have a cherry picker, I'd slide it in all together. Once you get it on the front motor mounts, just jack up the tail end and slide the crossmember in (which you'll have to remove along with the floor pan). May need to raise the front of the Jeep up to gain clearance if you're leaving the shifters on; a swivel on the cherry picker will help alot.

 

Great man, I am doing the same with a f-head engine I have. I am taking it a step further than you and eventually swapping over to TBI and a turbo.

deck the head any? Every 1 point of compression is around 5 hp per cylinder. Every .010 bored over is about a 1.5-2.5 hp gain per hole.

 

Thanks for the responses, much appreciated.

hehe, the #9 valve is for extra flow Took me a second to figure out what you were talking about...until I took a second look at my pics.

The head is decked some, but I do not know how much. I have 3 L head blocks, and I took the head from a motor that my brother and I got when we bought all of a guy's jeep part collection. The motor I got the head from had been going through a rebuild that didn't get finished...but the head was cut and straight, so I used it.

SIDSCJ: glad to hear that you think it's doable to install it all bolted together. Yeah, I can borrow a hoist that should work. I think it'll be much easier to install it this way...let's hope it is. I just have to finish my tranny rebuild, then put it together. I rebuilt the T90 a couple years ago so I could install lower t90c gears, but should have put a new 2nd gear and syncros in at the time...so I'm paying for it now and re-doing it, trans kept kicking out of 2nd before I pulled the motor and started this project.

Lifesgoodhere: Sounds like a great build you've got going on! Any thread on that? I've toyed with the idea of turbo too...maybe some day...but my thoughts were to go with propane.

BillF: I made a build thread when I made that header. I'm not sure where it is, but somewhere on this forum should be a thread titles Lhead Header, or something similar, if you're interested in how that thing came about.

 

It would be nice to have a header and better intake but I better leave my m38 stock.

 

my build thread was deleted. To much argument apparently, wether it could be done or not.

I like the propane idea, maybe on the next one I do.

I post the stuff about it in the early cj-5 and 6 section

 

Woohoo!

I'd bet you are looking forward to starting the engine, then to driving it.

 

That header is awesome! You should sell those o eBay or something.

 

yup, I can't wait to get this engine in the 3A! My wife and I used to go wheeling with the 3A almost every Sunday, and now we haven't been at all this summer. I really need to get this thing back on the trails, it's prime wheeling season!

So some snags on the tranny rebuild...I bought the new syncro unit and syncros, and got another 2nd gear too. I started to put it together, but I really don't like the looks of the new syncros I bought. I pulled one of my parts T90's apart and found it had basically brand new (or maybe they are brand new, no scuffing or wear on them) syncros in it. I compared those to the new ones I bought...they look a lot nicer. The new ones have almost round teeth with only a slight point, they feel lighter, and they don't have the grooves which I think help with lube. Anyone have any pics of what a nice oem syncro is supposed to look like? I think I'll run the nice ones from my parts rig and toss these new ones I bought...but of course use the new syncro unit/hub. My old syncro unit/hub (whatever it's called) was missing 2 of the spring tabs (found them in the bottom with a magnet)...no wonder it kicked out of gear.

more questions...how much end play is acceptable in the main cluster? What happens if there is too much?

 

yeah, you will be surprised how well the t-90 holds up. Usually, the ones I have torn apart, had minimal or no wear whatsoever. One I even knew the fella who had it and he was hard on it, grinding the gears a lot.

However I am getting ready to tear into one that had a 350 behind it, that will be interesting.

you want around .005 play. At least that is what I set the one I redid to, it works nice, and its still on one piece, which is a plus. I would check a spec sheet though just to be safe, I am also interested in what it should be.

 

To bad we can't get a dyno run on a project like this, I often wounder what is the actual HP gain.

 

Nice,
Do you have access to an M38 manual? The M38 powerpack was set up so it all goes in and out as an assembly. The engine, trans and transfer will all slip into place and you level it up from underneith and put the crossmember into place. It definately can be done.

Tom

 

I used a brick to help line things up for my l-head when I mated the tranny for one of my Jeep trucks. A large hammer helps too.

 

I have slid the engine and tranny in together a few times. No big deal.

I too would love to see some dyno pulls (at the flywheel) of some various engine builds.

 

thanks for all the replies!

I also wonder what the gains (if any) are from my header/intake. All I can tell you guys is that when I put my header on my old motor it definitely seemed to make it rev faster, and sound cooler, so that was enough for me R) I'm sure it has to help some, the stock set up flows horribly.

I'm hoping to put the entire drivetrain in tonight, as one piece...so let's hope it all goes well. Definitely thanks for all the replies letting me know it can be done, that helps my motivation and makes me worry less. I'll post up pics of progress when I get a chance...