Observations on a GT4 engine pull.

The engine came out of my GT4 yesterday. My two helpers were both FAA A&P mechanics with years of experience. One of them was my son, who will get the car when I go to the big winding road in the sky, so he had a vested interest. I studied most of the previous postings on the procedure and am particularly indebted to the excellent instructions from Tom O'Shay and Chris (Newto308). My objective in this post is to augment their contribution and provide a coherent checklist for anyone else who attempts this exercise.

I had done a lot of the prep work over the last couple of weeks, removing most of the pieces that would have to come off anyway to get the heads off: Carbs, Distributors, alternator, A/C pump, Coils, oil cooler, a lot of wiring, fuel and coolant lines, etc.

To protect the rear window I made a cardboard template and cut a piece of engineered floorboard to fit. I sandwiched the cardboard between the window and the floorboard and it fit perfectly. For the edges of the roof and buttresses I used a piece of plastic outside corner, 1" to a side ($7 at Lowes). One side covered the edge on the buttresses, a piece on top and the bottom covered the roof overhang. Then everything was covered with moving blankets.

I have a lift, so most of the work was done from the underside with the wheels off. We reattached the wheels and lowered the car on rear-wheel dollies for the actual lift.

The agile young fellows made quick work of the front and rear exhaust headers while I got at the gearshift rod and the clutch cable. E found that we had to remove the e-brake assembly from the bottom frame rail to get the rear header out. They then went after the axle shafts We were only going to disconnect them at the differential end, but Mike noticed a torn dust shield on the outer end of one, so we disconnected them and completely removed them. I'll rebuild the u-joints and replace the rubber bellows on them while the heads are being done.

The boys disconnected the motor mounts and we wrapped a tow strap around the front head and rotated the engine out.. One guy on each side to guide it, and I pumped the crane.

Total time was four hours, not counting the one hour break for my homemade pastrami Reuben sandwiches for lunch. Having professional mechanics like these guys to assist was essential. They just have the agility, tool knowledge and confidence I lack to get 'er done. I'll stare at a bolt for an hour, trying to figure how to get it off, they just grab a tool and go at it. They even cleaned up and put away all the tools after we were finished. No dents scratches or dings in the bodywork, no broken tools or parts. But they did put a sizable dent in the two 12 packs of beer and bottle of single malt scotch I stocked up on for their visit. They both liked the eggplant parmigiana and lasagna I made for dinner Saturday night, along with two bottles of Sangiovese - it was a hot day out there in the garage and we had to hydrate and replenish our electrolytes.

Engine pull checklist: remove the following

o Oil temp wire (front of oil pan)
o Ground strap (near speedo)
o Speedo wire
o Oil Pressure sensor wire (at the filter)
o Water temp sensor wire (under coolant crossover pipe)
o Distributors, wires. They have to come off to remove valve covers and remove cams, anyway.
o Coils and resistors
o Water tubes, lines
o All fuel lines. You’re going to replace them anyway, right?
o Throttle Cable
o Choke (enrichment device ) cable
o Carbs - why risk hurting them - they’re coming off anyway.
o Torque bar and mountings on valve cover and rear bulkhead
o Disconnect exhaust joints
o Dipstick and housing
o Remove muffler
o Front header (the one against the bulkhead) - Unbolt from head and allow the rest on chassis
o Remove rear header (we found we had to remove the e-brake assembly to wiggle it out the top
o Axles at transaxle
Make sure you clean out the allen heads and get the tool properly seated before applying torque, chances are you may strip some of those allen heads. You should replace all of those nuts and bolts with new ones anyway.
o AC compressor (wire it up under the fender (make sure you leave enough clearance to re-mount the wheel), or remove it completely.
o Alternator
o Starter wiring (starter can stay in car)
o Oil Cooler
o Clutch cable
o Shifter linkage rod (engage 4th or 2nd gear before disconnecting linkage)
o Motor mounts:
There’s lots of discussion on how to deal with them. Some say don’t remove the engine mounts in full, split them by removing the 2 studs on each mount only. Others say only remove the Engine mount center bolts, and bring it out with the rubber part attached.. What we did was remove the 2 bolts holding the flange to the bracket on the engine (basically the “splitting “ technique), but we also loosened the 3 nuts holding each bracket to the front of the engine. At half-lift, we removed theses brackets at the same time we removed the front header, mostly to make sure we had a lot of clearance at the rear roof overhang.

As it turned out the flange hung up on the right rear rubber motor mount during the lift, so we just removed it by unbolting the big bolt from the bottom. We might have been able to move the car on the rollers to free it, but my helpers opted for it’s removal.

We wrapped the strap around the head twice then tied it off in a loop. That proved to be too high, so we just put the hook below the knot and it worked out fine. When we started to pull the engine it has a little list to the left, so we released the tension and repositioned the center of the straps to get it right in the center of gravity, left to right.

When we lifted the engine it tilted and came straight out. For us, at least , lifting the motor out was the easy part. One guy on each side to watch and guide., one guy pumping the lift. We rolled the car out from under the motor, then re-installed, and tightened down the motor mount brackets. Then we gently lowered the motor onto the cradle and put a lag bolt through one hole in each bracket to secure it to the cradle.

When the full weight of the motor was on the cradle the wheels collapsed! That was because I (stupidly) used rotating wheels so the wheel could rotate to where it was offset from the center of gravity of the load. The ½” x 1” lag bolts I used just pulled right out of the wood. So we discarded them and put the cradle flat on the ground, positioned where I could work on it.

I removed a lot of parts prior to the lift day (oil cooler, alternator, carbs, etc.). Many guys say leave them on. From my perspective they were easy to remove, and their removal could prevent potential damage. For two weeks prior to lift day I sprayed every nut, bolt and stud I knew had to come off liberally with SeaFoam. All the bolts came off with the amount of force you would expect, even in the exhaust system.

The boys were a little concerned when we drained the oil sump and there was a bit of shiny, what seemed to be metallic residue on the plug. It was non-magnetic so it couldn’t be steel or iron. So It had to be aluminum, right? All Saturday night we discussed what aluminum part of the engine would be wearing.. My first thought was camshaft journals… Yikes! On Sunday morning we cut the oil filter open and found more of the residue. Then it finally hit me. It was the graphite I’ve been adding at each oil change for the last 30 years. Rub it between your fingers and it was slick, not gritty at all. I even got some graphite from the cabinet, mixed it with some oil and it looked and felt exactly the same. Mystery solved..

So the only disaster so far was my goof with the wheels on the cradle.

My apologies for the pics being out of order. I don't know how to get them inline with the text. The last one shows the bodywork protection strategy I used.
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I measured the motor mounts about a dozen times, but I originally planned to pull the engine with the rubber mounts attached. After much discussion with my crew we decided to split the mounts and leave the rubber in the engine bay. A last minute addition of the 4 x 4 blocks (with the engine still hanging from the crane) solved the problem. Countersunk and screwed down, of course. The critical dimension is the space between the two top rails, which I set at 21.5 inches, inside to inside. I used 1/2 x 8" lag bolts from the top and bottom plus Gorilla Glue to secure the upright legs. All 4 x 4's except for the angle braces and the two bottom rails, which are 2 x 4s. The whole thing feels pretty stable.

 

I believe it would be impossible to remove the engine without removing the front header, unless you had a very fancy leveling bar that allowed you to rotate the engine 90º counterclockwise (looking from the driver side). Look at the pictures below - we even had to remove the black L-shaped brackets from the engine block to get clearance as we rotated it out.

The second picture shows the geometry with the header installed. It adds about 5" at the critical rotation point past the heads, and over a foot at the bottom. Bear in mind that the differential still has to clear the welded-in bonnet latch at the rear.

If you can figure out a way to do it with the header in be sure to take plenty of photos and describe the procedure. I think I can speak for all who attempt this process, we'd love to have that option.

I describe the motivation and plan in this thread: http://www.ferrarichat.com/forum/308-328/456108-advice-solicitated.html and I still think this is the right thing to do. After my friend grenaded her GT4 engine last year I was losing sleep and having nightmares over those 40-year old sodium-filled exhaust valves, low compression readings and tightening exhaust valve readings.

This engine hasn't had the heads off since it left the factory. I'm having a hell of a time removing the intake manifolds (any suggestions?) and I'm sweating the head removal. After I get the intake manifolds and valve covers off I'll remove the belts and cams and run a leak down on each cylinder, then tackle the heads. Right now I'm covering or capping all of her orifices and will do a complete cleaning and wash down - can't stand to work on a dirty engine!
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What we did was remove all the nuts holding the headers to the heads with the engine in the car. We also removed the bolts on the flange joint between the headers and the muffler. That was pretty rough, but like I said, I have a lift so getting at them from the bottom with a lot of extensions, u-joints and same fancy fingerwork easier (not easy, just easier). I saturated them with SeaFoam penetrant for weeks before the pull so the nuts came off pretty easily. We thought we could remove the rear header with the muffler attached, but that had to come off, too (be careful, it's heavy).

As for removing the headers with the engine still in the car, there was an episode of Wheeler Dealers where Edd replaced the front header on a GT4. He unbolted the header and removed the muffler, then all the front accessories came off (alternator and A/C pump) and the RH side fuel tank. He managed to twist and pull the header out through the RH side wheel well. IIRC he also had to unbolt the motor mounts and jack up the engine a bit. It looked and sounded like a lot more work than just pulling the engine and removing the header at mid-lift.

You can get the rear header off by removing the torque brace, header nuts, muffler and the e-brake assembly - it comes out the top.

We've been debating having the headers ceramic coated. I hate to lose those beautifully-crafted aluminum heat shields on the front header. The rear one is long gone.

 

Deal! You can help when we put the engine back in!

Today I washed the engine down, soaked the valve cover gaskets in trichloroethylene (Solvent 184) and got them off. Still soaking the intake manifolds with solvent. Applied Krill to head bolts to let it soak in. I picked up a couple of horse syringes and big needles at the local farm supply - great for applying solvents and not spilling and wasting these expensive elixirs. You can even poke the needle directly into the gasket and try to get some inside.

I I think I might have to pull the valve cover studs out of the head to get the heads done - I tried the 2-nut method but had no luck. The machinist doing my heads will be stopping by this week to pick up his engine crane - I'll ask him if they need to come out. Any suggestions on a 6mm stud puller?

Tomorrow: leakdown test on all cylinders. Maybe take the belts and camshafts off.

Those air-injection manifolds are coming off, hopefully to be capped. Does anyone know the size/thread pitch or have a source for the caps? My son thinks there is probably a hollow brass fitting into the head, (anybody know?). If so, we can probably just remove the fitting and screw in a brass plug.

Here are some pics:
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Hi, Rob. I'm at about the same mileage. Mostly because of my trepidation to drive it over my concern about the valves, and my friend Memory's unfortunate incident with hers.

I used a 8400 lb. rated Haul Master tow strap (Harbor Freight item #61943, $12) 2 in. x 20 ft. Tow Strap

If you look at the first picture (8/19 post, above) you'll see that the head protrudes a bit over the block. We wrapped the strap over, around, and back up under that protrusion. When we put the tension on the crane it cinched up tight. Be sure to tie the knot as close to the head as possible - you have to get the engine pretty high to get it out and you don't want to find out you don't have it high enough to clear the body. It took some fancy marlinspike seamanship to undo that knot and remove the strap.

The engine sure is easy to work on out of the car. You're welcome to come up here to use my lift, but I think the logistics would probably cost more time and money than it's worth. I think you might want to invest in a scissor lift to do this job. When I'm done (hopefully in your time frame) I'd be happy to lend you the engine cradle, the wheel rollers and various other mission-specific equipment.

I'm going slow and documenting every step. I know there are more experienced and competent mechanics on this site, but there are still some rookies like me as well. My intention is to provide some level of confidence to the latter and help them keep these fabulous cars on the road.

 

First of all, the front exhaust header is staying the way it is. I might wrap the rear header with some kind of header wrap. Whomever welded those heat shields on was a real artist. I'm guessing it was done in a submerged heli-arc, popular in the 60's and 70's. Basically, the part was submerged in a big tank of inert gas and welded with a TIG-like torch and feed rod. I tried my hand at it when I was an Industrial Design student in the 60's and all I managed to do was make puddles of aluminum in the bottom of the tank. If it ain't broke, don't fix it.

Speaking of broke, I suffered my first casualty after I removed the belts. I loosened the big nut and pushed the tensioner with my hand, and the belt came off easily. When I removed the tensioner assembly it fell apart in my hands. It may have been cracked all along. Part #105200. Anybody got a spare used one hanging around at a reasonable price? I checked T Rutlands and eBay and they have them, so it's replaceable.

After I removed the cams I squirted some oil into each cylinder, rotated the engine a couple of times, and ran a leakdown test on each cylinder

Cyl %leak source

1 00 N/A
2 15 Exhaust
3 25 Exhaust
4 15 Exhaust
5 05 Exhaust
6 15 Exhaust, a little Intake
7 55 Exhaust
8 85 Exhaust

No Cylinder/Piston Ring leakage at all! Good news. These leakage numbers are like I expected, and confirm my decision to do the valves.

Here are what the cam journals and caps look like. The bearing surfaces on the cams are all smooth and shiny. I can run my fingernail across the caps and journals and not feel any grooving. Do you like the fancy parts organizers? I got them from Cluck-On
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Today I decided to tackle getting the heads off. I backed off the head stud nuts 1/4 turn (0.25 mm) in the reverse of the tightening order, and squirted some Krill around each stud. Then I took them out another 1/2 turn (0.5mm) and squirted them again. Then a full turn, squirt, and finally I removed them completely. I fished out the washers and counted them and then nuts twice to make sure I had them all (10 on each head).

Since I had the cams off and all the valves closed I thought I might just use the engine compression to break the heads free. I torqued the spark plugs back in and I considered using the starter, but decided that was too risky, so I muscled it around by hand. I could feel the compression, and on the third turn coolant began to squirt out of where the head gaskets are on both banks. I thought that was a good sign. More Krill on the studs.

A couple of whacks with a plastic mallet and the front head came off, just like that! The head studs had absolutely no corrosion on them and looked like they had some kind of black anti-corrosive treatment on them. They were smooth and not pitted or corroded. The rear head is a little more recalcitrant, but I can see it moving ever so slightly and feel some compression resistance when I rotate the engine. More Krill on the studs and headgasket seam, and I'll give it a one day time out to consider it reluctance to respect my authority, as Eric Cartman would say.

So on to inspect the cylinders, pistons and the head itself. It all looks good. The cylinder walls are clean and polished, no ridges anywhere. The piston tops look remarkably clean, should be easy to de-carbon (Scotchbrite pad?). The heads and valves have a little more carbon on them, but still look good, even #7 and #8 Exhaust valves, which had 85% and 55% leakage on the leakdown test. Mike The Machinist is coming by on Monday or Tuesday and I'll leave the valves assembled and let him take it from there.

I'm still having some trouble getting the Intake manifolds off. They may require the application of some heat. I did remove the air injection manifold on the head that is off. Those things take up about 20% of the exhaust port and I plan on plugging them with bolts and having Mike grind them flush when he cleans up the Exhaust ports. Here are some pics:
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Engine machinist stopped by yesterday to pick up his crane and inspect the head. he said it was heavily carbonized, and that the valve stems or seats may just have been hanging up on the carbon. He squirted some thinner into each port and looked for some leakage out of each valve. No leakage (the thinner must have washed away the carbon). He has to disassemble the head to really check, but he said right now it looks like all we'll have to do is replace the exhaust valves, touch up the seats and lap them. He thinks the intake valves are probably perfectly good, a light grind and lapping should make them like new.

This morning he called his valve supplier and had a long talk with him. He said he has supplied lots of exhaust valve replacements for 308s, even has the right blanks on hand, both 7mm stem thickness and 8mm thickness. I think I have 8mm. He recommended NIMONIC HD material. (specialmetals.com) - the same stuff they make jet engine compressor vanes out of. You can Wikipedia it. (https://en.wikipedia.org/wiki/Nimonic). The valve guy repeated all the bad stuff I had heard about sodium-filled valves, and all the wrecked engines they have caused.

Now I still have to get that other head off. I've been banging on it, squirting penetrant on the studs, etc. I put 80psi into one of the spark plug holes and it won't hold the pressure, I can see and hear air escaping along the head/block seam, past the head gasket. I guess I'll just have to keep working on it.

I found a replacement supporto tendicinghia for the one that broke at a recycler in Sacramento - $85. On Order.

 

Not as crazy as you might think. The length of the spark plug threads is the thickness of the material in the head. Pretty thick. I'm going to pump 80 PSI into the spark plug holes for an hour or so each while banging the head with a hard plastic mallet. If that doesn't work I'll go with the rope. My machinist friend wants to come over with his 4' pry bar but I think I'll look at that as a last resort.

BTW, I also have owned a BMW 850i for 20 years, and lots of guys have replaced valve stem seals using the rope trick method. SOHC with rockers and chain drive, you need a special fixture ($$$) to time the cams, and the engine definitely has to come out to get the heads off. Mine has over 150K miles and doesn't burn or leak a drop of oil. Knock wood.