Slant Six Forum
https://slantsix.org/forum/

Twiggy - Long Rod Aluminum Block Engine Build-up
https://slantsix.org/forum/viewtopic.php?t=23948		 Page 4 of 25
Author:  dakight [ Thu Jul 19, 2007 6:55 pm ]
Post subject: 
More oil to the rockers means more oil trickling down to the cam lobes it seems to me. There's got to be a "gotcha" or someone would have done it by now.
Author:  Charrlie_S [ Thu Jul 19, 2007 7:27 pm ]
Post subject: 
Quote:
I was wondering too if we just can cut a groove like hydro cams have and get plenty of oil on the rockers?
I have been using a small grinding disc, to do just that. I just grind a shallow, narrow groove by hand on the cam. The first one I did gave me a flood of oil, at the rockers. So I tapped the oil passage in the head, in the rear rocker stand, screwed in a plug with a hole drilled in it, to restrict the oil flow.
Author:  dakight [ Thu Jul 19, 2007 7:35 pm ]
Post subject: 
That seems to me like a much more effective way to distribute the oil. The rotating passage is probably ok at low RPM but the higher you rev the less time the ports are exposed to oil flow. It looks like a design for high speed oil starvation to me.

How deep and wide do you make the groove? Also, isn't there a grooved rear bearing available?
Author:  Doctor Dodge [ Thu Jul 19, 2007 8:58 pm ]
Post subject: 
There are reports about grooved rear cam bearings used in the 1980 and later hyd. lifter engines but when I order these sets today, they don't have the grooved rear bearing.

As noted, it does not take much of a groove to get lot's of oil flowing to the rocker arm assy., a .020 x .020 deep "scratch" is all you really need.

Here is a related message on cam bearing oiling:
http://www.slantsix.org/forum/viewtopic ... 677#147677

I have never seen much of a down side to having a good flow of oil out the rocker arms on a SL6. It provides the needed lubrication, plus it helps to keep the valve gear and head cool. You do need to have good oil return back to the pan but the drainback holes, even in a cast iron SL6 are large enough to handle it. The aluminum block has no restriction at all. (V8s are a differnt story, those engines can trap a lot of oil up in the cam & lifter area)

I would think that a heavy flow of oil around the valve stems would incraese oil consumption on a worn engine, especially if the valve stem seals are "baked-out" and broken.
DD
Author:  Charrlie_S [ Fri Jul 20, 2007 6:33 am ]
Post subject: 
I had always worked with the early solid lifter slants, before I came to this site. When I came here, I heard of the grooved rear cam bearing for the hydro motors, and looked into using it in a solid lifter motor. Guess what? I have never seen a grooved rear cam bearing. Looked at new bearings (no groove), looked at some disasembled, used engines (no groove). The cam journal has the groove, not the bearing.

As for cutting the groove in a solid cam, I do mine "freehand" it looks like it was done by a drunkin sailer. It is no way critical. I never measured mine, but Doc's deminsions seem fine.
Author:  Dart270 [ Fri Jul 20, 2007 11:23 am ]
Post subject: 
Rick,

Mine were reground at American Cams in LA, which I think no longer exists.

Oregon cams (see web) also says they do it.

The big cam I sold you guys (I think?) is a regrind, and Tilley has gotten 0.550" lift at least on a regrind.

Lou
Author:  Slant Cecil [ Fri Jul 20, 2007 1:11 pm ]
Post subject: 
Quote:
Rick,

Mine were reground at American Cams in LA, which I think no longer exists.
Lou, these guys?

http://www.americancustomcam.com/index.htm
Author:  Joshie225 [ Fri Jul 20, 2007 2:14 pm ]
Post subject: 
These guys are good:

http://www.oregoncamshaft.com/

They will grind just about anything that will fit on your core for $70. Last time I called they even have some new slant cores, but they require extra grinding (more than $70 worth) plus the cost of the core so they cost significantly more. I would expect you could get just about anything you desire on the new core.
Author:  Doc [ Fri Jul 20, 2007 6:02 pm ]
Post subject:  Crankshaft Install
Now that the cam checking - fitting work is done, it is time to install the crank.
(Do the cam checking before installing the crank to give yourself more working room)

Things to remember:
Install your lower timing gear (crank gear) onto the crank before installation into the block. Stand the crank on it's end, heat-up the gear and slip it on, give it a few taps to be sure it is fully seated.

Check your main bolts or stud length to the camshaft side threaded main cap holes. The main oil feed cross holes to the crank bearings intersect those threaded holes so incorrect or extra long bolts or studs will pinch-off the oil flow. (cast iron SL6) All threaded holes must be clean.

The Alm. Block SL6 needs the "two hole" main bearings. (all main bearing sets seem to come with 2 holes these days)

Image

Everything goes together per the FSM.
I set the crank in place and install the #3 main cap first. Run the bolts (nuts) down until light contact, then move the crank fore and aft in it's thrust - end play, this will help align the bearing halves along the contact face.

Install the other main caps with the bearing tabs both on the same side. (main and con rod caps only go on one way) Leave the main seal cap off for now. Use some plasti-gauge to check for correct oil clearence.

Once everything is installed and snugged-down, give the crank a spin to be sure it turns freely. (there will be light drag from the block side main seal)

Torque the caps one at a time, I start with 2 & 3 and work outward but it does not matter, just spin the crank after you tighten each cap, to be sure there is no interference problem(s) at any one point.

The number 4 main cap must be torqued before installing the main seal cap. Once the seal cap is installed, you can not get a socket onto the bolt heads.
DD
Image
Author:  1974duster kev [ Fri Jul 20, 2007 11:00 pm ]
Post subject: 
I was looking into buying a alum block sl6 for my rebuild i've been planning for sometime but it scared me off with what i've read about corrision,gasket problems etc. Not to mention i'm a 17 year old about to embark on my first engine rebuild and my dad has never done a slant six so i'm trying to get all the facts straight i can on my iron block to get it done right and without any problems
Author:  Doctor Dodge [ Sat Jul 21, 2007 8:15 am ]
Post subject: 
You made a good decision, you should do your first engine rebuild using the cast iron version of the SL6.

Once you successfully do one of those, the aluminum block would be the next step. The main issues with the Alm. SL6 is finding a good one to start with and finding the special head gasket this version of the engine uses.
DD
Author:  Dart270 [ Mon Jul 23, 2007 6:31 am ]
Post subject: 
Doc - thanks for the progress updates! I have an Al block on the garage floor now and I'm pondering...

Cecil - It could be those guys. They were near downtown LA, but could have moved out to Covina.

Lou
Author:  Pat Dawson [ Tue Jul 24, 2007 7:17 am ]
Post subject: 
My stock aluminum block engine now has 3000 miles on it since I rebuilt it a year ago. It runs fine and I only replaced bearings, rings, and gaskets internally. Cleaned the block deck with 80 grit around a flat file. Cleaned the crank with crocus cloth, and honed the cylinders. Original cam, lifters, oil pump, rods, pistons, and crank. Timing chain had been replaced by others and passed the stretch test. Ring gap is marginal but within usable specs. Must have got lucky that the engine wasn't too badly harmed in it's previous life before I pulled it out of the slavage yard. Head is a 1980 that I sent to the machine shop for re-conditioning. I didn't want to invest too much since I wasn't confident that it would be successful. With your help, the FSM, and a lot of research on the differences between the iron and alum. blocks, it turned out OK.

Anyway, that's old news. I just wanted to alert you to a letter in Hot Rod Magazine (Sept. 2007, just got it yesterday) about suggesting rebuilding an aluminum block Sl 6 for economy in response to Frieberger's (sp?) article on "Commuter Rods" from the previous issue. I don't have the article here but I will try to post it tomorrow. Any chance for publicity and awareness would be good for the cause and you are da man for the job.
Author:  440_Magnum [ Tue Jul 24, 2007 11:25 am ]
Post subject: 
Quote:
More oil to the rockers means more oil trickling down to the cam lobes it seems to me. There's got to be a "gotcha" or someone would have done it by now.
I would think it would be doubly good given that so much zinc is being taken out of engine oil. Flooding the lifter face/cam lobe interface means less dependence on the additives to prevent excessive wear.

On the other hand, I've read here that it gets problematic to run a high-volume oil pump on a slant because it tears up the pump drive gear. That's not an issue on the big-blocks I'm familiar with, so we do all sorts of things that bleed off oil pressure in return for better oil distribution, and we still have tons to spare because the distributor/oil pump drive gear is large enough that turning a high-pressure/high-volume pump isn't an issue. Its all a question of balancing the different needs of a particular engine.
Author:  Wizard [ Tue Jul 24, 2007 3:09 pm ]
Post subject:  ZDDP is important
Last year filled 1987 caravan's carbed 2.2L with german castrol 0W-30 oil and I knew this have good amount of ZDDP in it. Unknown to me engine had bent camshaft (.007 total) and had scored the #3 cam journal. Drove van for long time but for some reason that oil protected head from further damage till I had to pull head last May to replace HG (bubbling exhaust gases into coolant), turned out I had to replace head for cracked between valve seats and scored #3 cam journal.

Just finishing up caravan with correct head type bathtub not fastburn head due to spark control computer ignition curve programmed for bathtub combustion chamber.

ZDDP in the oil still is necessary for some certain situations like flat tappet/flat bottom adjusters to prevent camshaft losing lobes and in many diesels still need this for the injector pumps (cam operated).

Cheers, Wizard
Page 4 of 25 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/