4 cyl. Cam towers...

Discussion forum for the venerable 510, and its non-US counterparts, the Datsun 1600 and Bluebird.
User avatar
MicroMachinery
Posts: 47
Joined: Thu Feb 12, 2009 6:46 pm

Post

So the guy who owned the 510 before me ran it out of oil. When it seized, the it was the cam that seized in the towers. Can the cam towers be bored and have inserts put in? I know that sounds like alot of work for a head, but it's a peanut head, and I don't really come by those very often. Is this a wise pursuit? ..or should I just be scanning craigslist for a new one... Thanks.


Yellou
Posts: 16
Joined: Wed Aug 02, 2006 8:14 am
Car: `69 Datsun 510

Post

Dude!! get a set of good used cam towers install them and make sure your cam rotates freely. If it doesn't check both head surfaces for squareness. Boring and notching to hold the bearing in and trying to find bearings forget it, it'll cost you way more.

User avatar
evildky
Posts: 14713
Joined: Sat Jan 31, 2004 9:23 pm
Car: 71 240ZT, 87 300ZXN/A-T, 06 350Z GT, Tundra TRD RW
Location: Louisville, KY
Contact:

Post

I don't see why you couldn't line bore and bushing the towers, the trick is finding bushings close enough to be used and machined to fit, although it might be sasier to find new towers

User avatar
MicroMachinery
Posts: 47
Joined: Thu Feb 12, 2009 6:46 pm

Post

Sweet. I'd thought about doing that, but my manual says that's a big "NO NO" to disturb the towers.

Of course, running the engine without oil is a big "NO NO" and tends to disturb the towers, also. Someone shoulda told the previous owner that..

Thanks guys.

User avatar
evildky
Posts: 14713
Joined: Sat Jan 31, 2004 9:23 pm
Car: 71 240ZT, 87 300ZXN/A-T, 06 350Z GT, Tundra TRD RW
Location: Louisville, KY
Contact:

Post

if you replace the towers as a set and the cam turns freely in the new towers you should be fine, the issue is with machining tollerence, if the cam binds in replacemnt towers you have to have them cachined and line bored, the issue is to line bore either set of towers will require removing the cylinder head and I'm guessing you want to avoid that

Yellou
Posts: 16
Joined: Wed Aug 02, 2006 8:14 am
Car: `69 Datsun 510

Post

evildky wrote:if you replace the towers as a set and the cam turns freely in the new towers you should be fine, the issue is with machining tollerence, if the cam binds in replacemnt towers you have to have them cachined and line bored, the issue is to line bore either set of towers will require removing the cylinder head and I'm guessing you want to avoid that
No one machines these cam towers anywhere. I've never hear of anyone doing this. As long as you have the correct towers in their correct positions using their locating collars it shouldn't be a problem. Doing cam spray bars using the middle towers from the Z car has proven mix~n~match works. If your cam binds it isn't the towers it's the shape of the surface they sit on. Sometime when aligning the towers on a flat head you'll get some binding. This simply requires a plastic hammer to ever so slightly tap the towers into another position. I've done this so may time with 100% success I could even say.

User avatar
phlebmaster
Posts: 912
Joined: Wed Dec 31, 1969 5:00 pm
Car: 1973 240z L26 4spd rip roar and ready to go!

Post

I have pulled my cam towers on many occasions.

The reason not to do it is simple...binding your cam will wear it out the towers and send metal into your motor. Not good at all.

But if you are very careful you can put everything back together without incident by doin this:

#1. number your rockers in the order they sit in your head. carefully pull the rockers, springs and retainers keeping them as sets.

#2. Put your motor at TDC. Chock your timing tensioner so you don't lose your chain. Otherwise you will be pulling your timing cover. I use a 1" dowel about 10" long. Losten your cam gear and pull it off.

#3. loosten the 10mm allen head bolts that are holding your towers first and pull them out. Better be sure you have your torque wrench handy for re-installation. Re-torque can be tricky....you need to snug the head bolts back in first, then go in three to four steps tightening them down.

Head bolt re-torqueTry like 10lbs, 15lbs, 20lbs, 35lbs, and no more than the standard torque for the final step. Check your owners book for that last step. Then do a quick check on all head bolts at the top setting, being careful not to over torque them. Iv'e done that.

#4. Now your cam should spin freely. Then take out all of the other cam tower bolts. They are 10mm socket.

#5. Pulling the cam towers can be a bit tough at first..use a rubber mallet and tap very gently while you wiggle the cam towers. There will be several inserts that aid in lining up the towers and they get stuck sometimes. Be sure you DO NOT lose any of them. Your cam and towers should lift right off. Mark your towers 1-4!!

Re-install

#1. putting everything back in is pretty strait forward...just do the opposite of the steps you took to get it off. Mark the new cam towers 1-4 according to where you pulled them off the other head.

#2. Now the tricky part.....getting the towers to line up takes some finesse. If the head is in the car, then you will need to insert the cam into all of the towers making sure you have the right tower on the right cam bearing before you install them. If you don't, you will be pulling them again I promise. Use assembly oil like Lukas or something in the cam towers and on the cam bearing races.

#3. line up the cam towers on the head and get the inserts I told you about lined up and gently set them in. Then you take the cam tower bolts and set them in and get them started, but don't tighten them.

#4. Now put in your head bolts you pulled and get them started too leaving them loose.

#5. The allignment..... now you take your cam and turn it many times as you make the bolts tighter and tighter. This will ensure your allignment and you will know if the towers are off before you finish.

#6. once everything is tightened and torqued down, you put your rockers and springs back in. The trick with this part is making sure your cam does not move backward in the towers....keep it lined up!! Do not turn the cam with the head on the engine at TDC....if you do you may bend your valves on #1 and #4 cylinders. . Line up your timing marks ang you are golden.

Thats about it.


User avatar
MicroMachinery
Posts: 47
Joined: Thu Feb 12, 2009 6:46 pm

Post

Wow, that's above and beyond what I expected.

Thank you.

User avatar
phlebmaster
Posts: 912
Joined: Wed Dec 31, 1969 5:00 pm
Car: 1973 240z L26 4spd rip roar and ready to go!

Post

MicroMachinery wrote:Wow, that's above and beyond what I expected.

Thank you.
Do problem...that's what this place is for.


Return to “Datsun 510 / Bluebird”