CIS to ITB EFI conversion

[dannichols1474]

Got up early this morning and got out to the garage straight away. Was I going to have sufficient clearance between the valves and pistons? The short answer turned out to be yes - the JE 9.5:1 pistons with the WebCam S-cams, 1mm deck height and 0.25mm shave of the sealing surface on the heads turned out alright.

One cylinder #1: the exhaust valve had 2+mm (greater than 2.5mm) of clearance from 60 degrees BTDC to 30 degrees ATDC on the overlapping stroke, and the intake valve had minimum clearance of 2.0mm to 2.25mm from 2.5 degrees ATDC to 10 degrees ATDC and 2+mm of clearance everywhere else.

Once I had the results from cylinder #1, I chose to check the intake valve clearance only on cylinder #4 from 10 degrees BTDC to 20 degrees ATDC on the overlapping stroke. The minimum clearance was 2.5mm from 5 degrees ATDC to 10 degrees ATDC and 2+mm clearance everywhere else.

Per Wayne D's 911 engine rebuilding book, the minimum clearance for intake valves is 1.5mm and for exhaust valves is 2.0mm, so my engine passed the piston to valve clearance check!

Test set up for clearance checking:



Data record sheet of piston to valve clearance:

[dannichols1474]

I got the cam towers and chain boxes removed from the engine. Now I can re-clean the cam tower and the top of the heads in preparation for final assembly with sealant.

Made space on the workbench to layout all the camshaft parts from the 1,2,3 bank.



Back down to heads on the 1,2,3 bank.



Breaking loose the camshaft bolt on the 4,5,6 bank.



Camshaft parts laid out on the workbench separated and labeled by bank.



Been here before....

[dannichols1474]

It's going to be hot this week so I got out to the garage at sun up so I could do the cam tower assembly with sealant (Loctite 574 - orange goo) while it is 70 deg F not 90+ deg F.

During mock up I didn't bother to put in the oil return tubes (exhaust side from cam tower to crankcase), but this time it's the real deal so they must be installed. Notice these are the collapsing type tubes and I have installed them into the crankcase on the 1,2,3 side while they are still collapsed for shipping.

It didn't even dawn on me they needed to be expanded until AFTER I applied the sealant to the 1,2,3 bank cam tower - operator error! I corrected that mistake by expanding and locking in place by moving the cir-clip to the upper groove for the 4,5,6 bank.

All I could do was to move forward with getting the cam tower tightened and torqued down to the heads (in expanding / crossing pattern to 18.4 ft-lbs) - repeated the torque sequence 2 more times to make sure I didn't have any "movers", nuts that move a bit before the torque wrench clicks. Then I tightened and torqued down the heads to the cylinders (two steps: 7.4 ft-lbs first in pattern, then 23.5 ft in pattern) - same process, repeated 2 more times at final torque setting only.



Underside of cam tower cleaned with IPA using lint free wipes in the area that has sealant applied.



Sealant applied to the underside of the cam tower and used an acid brush to move the sealant around so it is applied evenly.



Here the cam tower on the 1,2,3 bank is installed on the heads and everything is torqued down.

The oil return tubes? I used a large (24 inch) pair of channel lock pliers to "pull" the upper section of the tubes into the cam tower while I held the lower section in place by hand. Then I moved the cir-clip to the upper most groove to lock the tube length.



Then I repeated the entire process for the 4,5,6 bank. After I got done installing the cam towers, I was rotating the engine on the engine stand and cleaning off excess sealant that had squeezed out from between the cam tower and the heads when I noticed there was something strange about the 1,2,3 bank cam chain.

When I looked at the 1,2,3 chain closely, I saw it was bound up. Then I looked into the crankcase and saw the problem: the chain had come completely off its sprocket on the intermediate shaft and was bound up against the front crankshaft counter weight of cylinder #4!!

I freaked out - and thought if I can't get this chain back on its sprocket, I'm going to have to tear this entire engine apart to fix it.

That episode lasted about 2 minutes, then I thought there has to be a way to fix this. If the chain could fall off the sprocket, then there must be enough clearance around the sprocket that the chain can be moved back onto the sprocket.

So I pulled out a long, thin flat blade screw driver and started poking at the chain in the crankcase. Then it dawned on me that I need to remove the inboard chain ramps to get move maneuvering room - so I removed both the upper and lower chain ramps.

With the chain ramps out of the way, I was able to fiddle with the chain and got it back onto the rear set of teeth on the sprocket - making progress. I continued manipulating the chain and was able to get it back on its sprocket and then I re-installed the inboard chain ramps. What a relief!!

Being thoroughly traumatized, I decided to continue working in the now hot garage and get the chain boxes, camshafts, idler sprockets, outboard chain ramps and mechanical chain tensioners re-installed with the required assembly lube and gasket sealer applied so there would be no chance for the cam chains to come off their intermediate shaft sprockets.

[icarp]

A thought from my experience . Sealant applied to the underside of the cam tower should be a line about the width of a narrow sharpie marker . Run the line around the outer edge of the flange , then a line down the middle , trace around the spring holes , that should do it .
The gap is less than one thousandth , hence the tiny amount of 574

[mikedsilva]

Originally Posted by dannichols1474

Pls post the photo showing the amount of squeezeout .. that's a LOT of 574...

[dannichols1474]

Today I got the cam timing done and tried to install new chain tensioners (OEM from Pelican Parts, oil fed style) but the first tensioner didn't "pop" when I pulled the pin. So while I held the idler sprocket taute with one hand, I reached the workbench and grapped the second new tensioner and installed it (this one worked - the tensioner entended with a "pop" when I pulled the retaining pin).

I got the phone with Pelican Parts and without difficulty I got a replacement tensioner ordered and got an RMA to return the faulty tensioner via FedEx on Pelican Parts' dime.

I also got the o-rings for the chain tensioners ordered, they do not come the engine gasket kit.

Then I turned my attention to installing rocker arms. I had installed the intake rocker arm on cylinder #1 and #4 as part of the camshaft timing process. Next I installed the remaining rockers on the 1,2,3 bank and got the valve covers installed.

[dannichols1474]

Today before I resumed installing rocker arms on the 4,5,6 bank, I installed the distributor.

I rotated the crankshaft to "Z1" for cylinder #1.

Before removing the distributor during engine tear down, I made a paint mark on the outside of the distributor body corresponding to the rotor orientation and another set of marks on the timing adjustment slot where the stud from crankcase goes thru indicating the position of the distributor. Then when I installed the distributor I just lined up the marks and drove in the distributor, the sealing o-ring requires a tap of a hammer to the distributor shaft (with a wood block in between) to set the distributor in place.

Then I installed and torqued down the flywheel using red Loctite on the flywheel bolts.

Finally, I got busy installing the rocker arms for the rest of the 4,5,6 bank and setting the valve lash. Then I installed the valve covers.

Next, I installed the oil cooler. I coated the thick rubber sealing rings with clean motor oil, installed then on the crankcase, then positioned the oil cooler onto its 4 mounting studs and tightened / torqued down the mounting nuts using new spring steel washers.



Once I get the replacement timing chain tensioner and the o-rings for the tensioners, I can close up the timing chain boxes.

[dannichols1474]

Today was a short day in the shop. I installed the oil supply lines to the cam towers.

[dannichols1474]

Went back out to the garage for a short second session. I installed the fan assembly and the fan belt.

Note: I discovered the fan hold down strap can't be installed with the distributor and the oil pressure sending unit installed. So I pulled the distributor and the oil pressure sending unit, fed the fan hold down strap thru the openings at the base of the fan housing cradle, mounted the fan and tightened down the fan hold down strap, then went back and re-installed the distributor and the oil pressure sending unit.

Next, I installed the small copper webbed ground strap between one of the upper case perimeter nuts and one of the nuts that holds the fan / alternator in the fan housing.

Finally, I mocked up the fan shroud and block off plates just to see how they fit and look. Once I get the engine wiring harness in place and make the connections to the back of the alternator, I can do the final install of the fan shroud (I'll double check Wayne D's 911 engine rebuilding book first to see if I've missed anything - like I didn't do with the fan hold down strap).

[dannichols1474]

Today I got the wiring to the back of the alternator connected, as well as, connecting the oil pressure sending unit, the oil temperature sending unit, and the oil pressure warning light switch. Then I was able to install the engine shroud and the ITB's.

Installed a new rubber grommet in the shroud where the alternator wires go thru.



Made the wiring connections to back of the alternator.



Connected the small copper webbed ground strap to the back of the alternator frame.



Getting close....

[al lkosmal]

It's looking real, Dan........getting close to fire-up time.

regards,
al

[dannichols1474]

When I finished the morning session, I noticed that when I installed the ITB's I didn't get the routing of the intake vacuum hoses correct. The 4,5,6 bank was okay, but the #2 and #3 hoses were routed around the #1 ITB. When I installed the ITB EFI, I had routed all of the 1,2,3 bank vacuum hoses to come to the engine center between the #1 and #2 ITB's.

Fortunately, this ITB system is pretty modular so I just disconnected the throttle linkage and the ITB's on the 1,2,3 bank, lifted the ITB's off their intake port on the heads, moved the vacuum hoses to the correct routing location, and lowered the ITB's back down onto the intake ports and buttoned everything back up.

While I was in the garage, I also installed the ignition coil and connected the ground from the engine wiring harness to the rear ignition coil mounting stud.

This project has been and continues to be all about the details....

[dannichols1474]

I received the replacement timing chain tensioner today, so I installed it and pulled the release pin and again the plunger didn't extend. In desperation, I grabbed a ball peen hammer and struck the tensioner body near the plunger. On about the third successively harder blow, the plunger finally broke free and popped out.

Now with both new chain tensioners installed, I lubed and placed the o-ring on the oil inlet of each tensioner, then installed the chain box covers. I also re-installed the oil temp sensor for the EFI system into the chain box cover for the 1,2,3 bank. Lastly, I installed the oil supply lines to the chain tensioners.

[dannichols1474]

I got the engine mounts attached to the front of the engine and I installed the engine tin except for the piece that goes on the back of the 4,5,6 bank. I will install that along with the clutch once I get the engine off of the engine stand and remove the mounting yoke which will happen after I receive and install the new exhaust headers I have on order.

[mb911]

an idea to clean up itb vacuum lines. This setup works very well on my car.

[dannichols1474]

Today I received and installed my new exhaust manifolds - Bursch 1 3/4 inch stainless steel headers. If I get cold, I'll have to put on a jacket....



Next stop, rent an engine hoist and get the engine off the engine stand, unite it with the transaxle and install the power unit into the car.

[mb911]

Originally Posted by dannichols1474

Today I received and installed my new exhaust manifolds - Bursch 1 3/4 inch stainless steel headers. If I get cold, I'll have to put on a jacket....



Next stop, rent an engine hoist and get the engine off the engine stand, unite it with the transaxle and install the power unit into the car.

Looks great. That is a big primary size. Top end will be great. Low end may suffer . Your work looks very nice

[TheBrokePilot]

Those look very nice. Do they already come with a bung for the o2/wideband sensor or did you get one welded in?

[winders]

Yes, those headers are too large in diameter for that engine. I wouldn't go 1 3/4 on a street engine until the displacement was at least 3.6L.

[mb911]

Originally Posted by winders

Yes, those headers are too large in diameter for that engine. I wouldn't go 1 3/4 on a street engine until the displacement was at least 3.6L.

Yup low end will really suffer. Should be 1-1/2”