Frustrating cam install

[richpet]

In the middle of installing the Comp cam. It slides in all the way right up to the back bearing. Then stops. Won't go in. Did I miss something?

[RS_Capri_85_5.0]

Is there a burr on the rear cam bearing outer lip? Did it move in or out, perhaps it it twisted in the block hole? Do you have a way of measuring the old cam's rear bearing diameter? Try to install the original cam and see if it fits. IF it does, the new cam's rear bearing might be dinged, or the last bearing surface mis-machined.

Be sure the cam bearing windows line up perfectly with the windows in the block, not cocked or crooked. If you have a Boroscope or some other way of checking the bearings as they are, I would do that first. See if one or more bearing shifted, is crooked or damaged.

Are the cam bearings original or did you replace them? The same things apply to new cam bearings. Twisted, crooked in the hole, ding on the lip etc. On the roller cam 5.0's I replaced cams in, the bearings were reused, the new cam always slid right in. Use a long bolt screwed into the gear end of the cam to provide leverage,. carefully and gently installing the new cam. The same care is applied in removing the old camshaft, preventing the bearings and lobes from contacting the cam bearings being moved or damaged.

If push comes to shove, new bearings may be needed. Look for a local place to rent the cam bearing installer. There may or may not be enough room with the radiator and condenser removed to install new cam bearings. The bearing sets themselves are cheap enough.

[richpet]

I bought the block ready to go, new cam bearings installed. Originally intended as a marine motor, but that should not matter. I can feel no nicks or burs anywhere and the cam bearing surfaces also feel smooth. It slips in right to that rear and stops cold. I installed the front pin so I could rotate the cam more easily. No dice.

Just went out and discovered that the rear cam bearing is not square. The bottom edge of the bearing is more forward than the top. I can feel the difference with my finger when I get up in there. CRAP!

Is it possible to rent a cam bearing installation tool and 'square-up' that rear bearing? I don't live in town so bringing the block in (it is on a stand) is a bit of an ordeal/inconvenience to say the least.

[richpet]

BTW- that was based on your suggestion, thanks! Didn't think the last bearing would be a bit cock-eyed.

There are a couple marks on the bearings from my three attempts to install, probably from where I stopped to move my inside hand past the next main web, but they feel smooth to my fingernail so should be fine.

[homer302]

I am pretty sure (I have built my own engines before but choose not to now) the cam bearings have to be installed in order. So if the first one in needs to change then I believe all the ones in front have to come out. However, at the same time, I also don't believe that really costs much money to do since it is already apart. I am sure it is easy enough to check and heck, it's been over 20 years since I did one so maybe there is a tool you can somehow do it with.

[richpet]

The rear bearing is normally installed from the back if I understand correctly, so the rear plug would have to be removed and a new one also installed. Of course, the block has to be off the stand first. Not a huge amount of work, just more than I planned since I thought it was good to go when I got it. All the other bearings seemed fine. If I can't square it up from the front, I will have to remove and replace the rear one from the back it appears. Not insurmountable by any means, just frustrating.

[Walking-Tall]

It might not just be a rear bearing issue, but more likely two or more of the others installed out of order. The rear bearing having the smallest inside diameter, it's not likely a smaller than the smallest one was installed back there... though anything is possible. All of the camshaft journals are (differently) sized to match with the bearings, as well as to ease usual installation from front-to-rear. It could be any of the cam bearings not jiving with a camshaft bearing journal, because if the cam stops short like you've explained, none of the camshaft bearing journals are residing inside of their camshaft bearings... possibly installed out of order... since they are smallest to largest, rear to front. Maybe the rear is cocked or nicked, maybe not. Cheapest route I can imagine would be to measure each camshaft journal, and reach into the block (less crank/rods/pistons) and measure the installed camshaft bearing inside diameters (a dial caliper should be accurate enough with the size differences), purchase a bearing set if necessary, and correct the probable two (or more) that may quite likely be installed out of order. It's the only real way I can think of so you can be certain.

[Walking-Tall]

From the '79-'93 Mustang Haynes manual...

Camshaft's journal diameters:
#1 - 2.0805-2.0815"
#2 - 2.0655-2.0665"
#3 - 2.0505-2.0515"
#4 - 2.0355-2.0365"
#5 - 2.0205-2.0215"

Camshaft bearings' inside diameters:
#1 - 2.0825-2.0835"
#2 - 2.0675-2.0685"
#3 - 2.0525-2.0535"
#4 - 2.0375-2.0385"
#5 - 2.0225-2.0235"
(So, approx. 0.015" I.D. decreases, front-to-rear... substantial enough differences, requiring absolute correct location installation)

Journal-to-bearing oil clearance:
Standard - 0.001-0.003"
Service Limit - 0.006"

[richpet]

I could actually see that the rear bearing was cocked- closer to front at bottom than top.

Got a bearing installation tool and held it in line while I had the spousal unit tap with the hammer. Going to see if the cam goes in now after work tonight.

Sent from my XT1565 using Tapatalk

[ThunderStruck]

Auto Zone has cam tools $20 deposit

[richpet]

My Autozone did not have that tool to rent. BUT, good news anyway. The guy who did the original work on the block in 2007 told me just to drop it by and he would install a new set of bearings, no problem. So I set the block in the back of the Bronco and do that Monday morning.

I did try straightening the bearing with a hammer/bearing tool but no dice. Can't get that precise on alignment the way I tried.

[Ourobos]

Broncos and Mustangs.. My kinda guy right here ^

[RS_Capri_85_5.0]

I'm glad to hear your machine shop is stepping up and taking care of this for you. It's good you caught the issue before proceeding. Imagine if you will, you were able to install the cam with the rear bearing installed improperly and you didn't notice it

You definitely want cam bearings installed correctly, squarely with the oil windows lined up 100% with the block windows. Not sure on Ford blocks, but others, for instance true Pontiac made motors installed in GTO, Trans Am/F-Bird, Catalina, Grand Prix etc;.. if cam bearings spin, or are installed with the windows blocked, even partially, cause oil pressure and starvation issues to the top end. Insufficient or no oil supply to lifters, rockers, pushrods is the result. This happened when I had a RA-IV 400 Pontiac built for my GTO by a local machine shop.

Needless to say, running 20 minutes at 2500 rpm to break in the cam, then chasing the resultant noise top end caused major damage to the top end components. The oil starved components put metal into the oil supply which contaminated the oil. Oil pump rotor, rod and main bearing damage and well as crank journal scoring.

The machine shop ate the damage. The had to turn the crank 10 under, replace the cam, lifters, rockers, pump, all bearings and pushrods. Fortunately, the pistons were not damaged, but they replaced the rings and rehoned the bores. That way the break in process would be started from scratch. Improper cam bearing instal is nothing to mess with. The damage adds up quickly as does the dollars to repair it.

Again, not 100% sure, but I recall replacing cam bearings in my 5.0 Capri while in car from the front. IIRC, the rear bearing cap is installed from the rear with the trans out or the motor removed. It is installed to a specified depth. The cam bearings I installed in my 5.0 were just like any other motor, largest to smallest, back to front.

[richpet]

He is a very highly respected local engine builder with his shop on the same property as his house. He was more than happy to say he would rectify it. Should be doing it tomorrow morning. The block is on a stand so access is easy. Currently on a piece of cardboard in the back of the Bronco.

I am kind of a Ford guy at heart. My dad worked for Ford all my life. Mechanic and then shop foreman when he retired. Retired from a local dealership. I think most all vehicle makers have some quality stuff, but I do prefer my Fords. The Bronco came because I needed more towing capacity than the Rodeo I had. So I bought this '90 brick-nose about 6 years ago. 351, auto, found maintenance receipts in glove box going back to 1993. It even had a brand new Ford long block installed at about 100k. I bought it with 155k and currently am sitting at 198k.