351W rockers.

bly · #1 (**permalink**) 08-11-2008, 02:09 PM

I have 351w, can a guy adjust rockers with motor running? Is it doable? Any expertise on this subject would be greatly appreciated..
Thanks,Bly...

blykins · #2 (**permalink**) 08-11-2008, 03:12 PM

Yeah, you can do it, but it's a whole lot easier and more accurate to do it with the engine off.

bly · #3 (**permalink**) 08-11-2008, 03:18 PM

Thats kinda what I figured, I had a friend tell me the best way to do it is with running. Seems to me It would make a mess of things.
I will do it not running, Thanks...

blykins · #4 (**permalink**) 08-11-2008, 03:19 PM

Yeah, it's messy because oil is there is oil flow to the top of the heads and without a valve cover on the head, oil will go everywhere.

You running a hydraulic cam?

bly · #5 (**permalink**) 08-11-2008, 03:24 PM

I am running a hydraulic cam. I set the rockers on engine stand, Started the other day and the rockers are making alot of noise. Must not have got them set just right. Engine is in very close quarters, so it will be a job to reset in car.
Oh well will have to do it.

blykins · #6 (**permalink**) 08-11-2008, 03:30 PM

It's not bad. Just take your time.

Start with one cylinder, bump it over until the exhaust valve is just starting to open, and then set the intake valve. Get zero preload by feeling the pushrod, then go a 1/2 turn past that. Then bump it over until the intake valve on that same cylinder is starting to close and set the exhaust valve the same way. Then just move to the next cylinder.

Some guys use the TDC method, but I feel the EVO/IVC method is the best. It works for mild cams and it works for the wildest ones.

Do you have good oil pressure? Did you prime the oil pump to make sure oil is getting to the rocker arms?

CHANMADD · #7 (**permalink**) 08-11-2008, 03:36 PM

if you set them out the car let the motor run a little and the lifters may pump up. you gotta let the oil pressure build up.
john

VINCENT RUDI · #8 (**permalink**) 08-11-2008, 04:12 PM

You Do Not Need To Readjust Rockers On A Hydrolic Lifter Cam If The Install Was Done Properly.first Make Sure The Flat Part Of The Rocker Shaft Is Facing Up So The Nut Sits Flush, Simple Mistake Then Adjust The Rocker Arm A 1/2 Turn Passed Zero Lash. Mark The Top Of Your Set Screws, People Look At Me Like Im Nuts When I Do That, But Im Not The One With The Problems In The End. Also Check Your Clearences Between Your Rocker Arms And Your Springs That Will Also Pose A Problem. Also Check Your Push Rod Sizes Sometimes The Exhausts Are Bigger Than The Intakes Or Vise Versa Or The Size Of The Pushrod Is To Short And The Rocker Arm Has To Much Travel. Good Luck

bly · #9 (**permalink**) 08-11-2008, 04:13 PM

I primed the pump, Have great oil pressure, and the engine has run for about half hour so far. Still noisy...So I suppose they need some adjusting..

I have put a couple engines together, this is the first i've had problems with rockers, usually hyd. cam & lifters are pretty easy form my past experience.

must've got something wrong...
Bly.....

blykins · #10 (**permalink**) 08-11-2008, 04:14 PM

You think you got a hold of a bad lifter? Can you pinpoint the noise to one lifter or are they all clattering?

VINCENT RUDI · #11 (**permalink**) 08-11-2008, 05:01 PM

Your Valves Bay Be Hitting The Pistons. How Crazy Is Your Cam

bly · #12 (**permalink**) 08-11-2008, 05:51 PM

OK, now I am wondering if I have a more serious problem than first thought. To give a little history on engine, Its in an 83 mustang I have had for years, engine was built probably going on 18 years now. I drove it maybe once a year. Now that I am without a Cobra I have been resurecting Mustang.

Engine ran smooth and was really quite. Head gasket blew, fixed that, then decided I would put in a bigger cam. That is really the time I did start having valve train problems. After new cam installation I had a heck of a time getting valves adjusted, they never were as quite as before new cam.
I also had a strange sound, a very intense rattling, almost like a bad lifter but faster, but it was at faster RPM's.

I started to pull motor apart again to find problem, found nothing on top end, but when I pulled pistons I had a broke ring on #5 I beleive it was. I reringed pistons and new bearings, put back together, nothing else new except lifters. Now i am having this valve train problem again. I havent noticed the strange sound as I have not really reved motor much.

Is it possible I did go to big on cam? Here are the specs @.050 Int is 230 Exh is 236. valve lift .519 Int and .523 Exh. I have an old set of Aluminum heads, they are Alan Rute or something like that.

Any ideas???

blykins · #13 (**permalink**) 08-11-2008, 06:05 PM

That's not really a large cam. The lift isn't much at all....but of course if your pistons don't have enough piston/valve clearance, it doesn't matter how much lift you have. Did you check piston/valve clearance when you installed?

One thing that you haven't mentioned is whether or not the cam is a roller or flat tappet cam.

If it's a roller, that will eliminate the idea of the cam going flat.

If it's a flat tappet, I would put a dial indicator on a lobe and see if you still have the lift that you should have.

bly · #14 (**permalink**) 08-11-2008, 06:12 PM

Brent, it is a hyd flat tappet cam, I will have to tear apart again and check cam, I was so so close to putting in a new cam but just went with new lifters, maybe it did go flat. hmm.
Like i said before, this engine was quite as a church mouse before I put this cam in.

Thanks again, Brandon..

blykins · #15 (**permalink**) 08-11-2008, 06:20 PM

I would check that first thing. With oil additives not being what they used to be, lots of people are struggling with flat tappet cam installs.

I'm trying to think of the easiest way to check without disassembling.

When it's running, are there certain valves that make noise....or do all of them make noise?

If you have a couple of cylinders that seem to be noisier than the others, you could start the engine to build up oil pressure, or prime the oil pump to build pressure. When the lifters are pumped up, you could put a dial indicator on the rocker arm and check gross valve lift.

If you have enough rocker arm clearance/adjustment, you could also adjust an arm so that you bottom the lifter out and make it solid. Then you could check valve lift that way also.

The only other option I can think of is to pull the intake and check lobe lift on the lifter (preferrably solid lifter so that it doesn't compress) or on the cam lobe itself if you have a dial indicator fixture to do that.

I hope this isn't the case, but with it being a flat tappet cam, it's a good possibility....especially when you say that you ran them on the stand but now it's clattering.

bly · #16 (**permalink**) 08-11-2008, 06:25 PM

Brent, I recall reading something a while ago about checking if cam is flat, if your pushrods dont spin when turning over engine that is a good idication you have a flat lobe?
Have you heard of this technique???
Brandon....

blykins · #17 (**permalink**) 08-12-2008, 01:58 AM

Well you're basically just checking to see if there's been any increase in valvetrain play due to a lobe going away.

Yours will probably spin if they're making that much noise....whether the cam is flat or not.

VINCENT RUDI · #18 (**permalink**) 08-13-2008, 06:43 PM

If you have aftermarket heads on the motor it may be possible that the heads were shaved or the deck and valve clearance is not the same. I would suggest geting thicker head gaskets before buying anthing pricey. The cam you purchesed my be for a stock head motor, it would have more clearance. If its not stalling the motor out i think you can get away with just the gasket.

VINCENT RUDI · #19 (**permalink**) 08-13-2008, 06:56 PM

How long have you ran the motor with the new cam? It would take a while to whip a cam lobe with hydrolic lifters. Do you have two differnt size push rods for intake and exhaust? If so i would check to see if maybe one or two are switched. If i could hear the motor it would be easier. Also do a compression test to see if you have a bent valve,that just came to mind.

bly · #20 (**permalink**) 08-14-2008, 12:38 PM

Vincent, I do have aftermarket heads, Pushrods are all the same length. The only thing I have changed on engine is the cam. Engine ran fine and valve train was fine until I changed cam.
I cant really go with a thicker head gasket as my heads are cut for o-ring head gaskets. I am not sure they make any thicker o-ringed gaskets.
Engine is not stalling, just alot of rattling and a suspicious sound.
I have ran this cam probably 2-3 hundred miles before I pulled engine apart.
I will try a compression check this weekend.
If that is good I might cart it off to a local mechanic I know to troubleshoot it out...
I realize it is hard to troubleshoot engine problems without hearing them run, but thanks for all the input, any other suggestions would sure be welcome....

Thanks,Brandon........