Need help 427 engine problems

[priobe]

Hello All,

I currently have a 427 FE in my Cobra. On Saturaday I took the car for a test drive (very light driving motor was still warming up. I reach the corner which is half a block away and made a left hand turn. As soon as I hit the gas still light driving I heard a metal sound coming from the engine. I pulled over for inspection and did not see anything. I then turn off the motor and for a better inspection and did not see anything. I return home and parked the car. The next morning I decided to remove the valve covers and inspect the rockers. Everything looked fine again. When turnin the motor by hand I heard a click noise just I I heard with the motor running. I am running the steel crank with the wider journals and rods.

Could this be a rod bearing that is bad? Is there anyway that I could determine if the bearing are shoot before I pull the motor?

This motor does not have too many miles on it, I am still in the build process.

Thanks for any help that can be provided.

[Rick Parker]

It's difficult at best to attempt to diagnose an engine problem "over the phone", I feel for you. If you are not visually able to see anything under the valve covers, it's time to dive deeper before you run it again. It sounds as if it is time to remove the engine and open it up before any further damage is done. Can you pull the pan with the engine in the car, that may be the next phase. Pull the distributor first. Check the gear.

Good luck

[priobe]

Thanks Rick,

I completely understand about trying to diagnose the problem. I have rebuilt engines before in the past, not 427. I guess my best bet is to pull the motor and strip it down. does anyone know clearances that are needed for bearings.

[blykins]

You'll get several different opinions, but the rod bearings should be around .002" and the mains between .002-.0025".

A 427 isn't different from any other engine with respect to how everything works. I'd pull the pan and let someone turn it over for you.

BTW, do you have a windage tray?

[FFR428]

[QUOTE=priobe

I am running the steel crank with the wider journals and rods.


NASCAR 427 crank and rods? Is the crank still std/std?

G.

[priobe]

Blykins,

I am using the Armondo's pan which is a t shaped pan. This pan has the trapped doors on the inside


FFR The crank is a steel Crank with the wider journals and rods. And yes it is std/std

[blykins]

I see by your other post that you're looking for bearings.....did you find out what happened? Did it spin a bearing?

[767Jockey]

You sure it's INSIDE the engine? Start easy, remove belts, etc - try turning it over or running it for a second or so. Look inside the distributor, all the easy stuff first. Check up inside the bellhousing, make sure all is together in there as well. All long shots, I know, but it's easy stuff. Sure beats tearing down your engine, only to find out a water pump, alternator, throwout bearing or clutch fork broke.

Try removing the intake next. I never heard a bad rod bearing "click" - just a guess, obviously, but I'd think a bad valvetrain component would be more likely to "click" than a rod bearing. Good luck.

[priobe]

AAAHHHHHHhhhhh!!!!!!!!!!!

Gentlemen Thank you for your patients and wisdom. I could not shake the thought of the Cobra being sick so as soon as I got home I took your advice and decided to look under the valve cover of the drivers side. And behold, I found a broken push rod.

Now my question is how did this happen? This rod broke at the cuped end of the rod. It really banged up my rocker arm pretty good and broke the cup on the end of the push rod.

These push rods were made by smith brothers (I think that is the name) and the rockers are Dove.

Does anyone know if they sell Dove rockers individually?

[Rick Parker]

Find ALL the pieces!

[priobe]

Any ideas where to look I.E Do I need to remove the intake?

Also, do you know if Dove sells a single rocker? And what would cause this?

[Ron61]

Start by draining the oil and removing the pan to see if any pieces fell into it. If you can't find them all, then my suggestion would to be pull then heads and see if you can flush out all passages. The other alternative and probably the safest one is to remove the engine and completely tear it down and clean everything. Even a tiny particle left in can cause major problems later on.

Ron

[blykins]

I'd pull the pan and look around...pull a rod bearing and make sure it hasn't been scarred. Clean the pickup, change the filter, etc.

You could call Dove and see if they sell individual rockers....also you could try Gessford or even Comp Cams, as they are the same piece.

It's hard to say what would cause it...it could be a weak pushrod or maybe the adjuster broke first.

How's the valve stem look? Also, is the rocker shaft bent? Stands broken?

[Jerry Clayton]

Cut the oil filter open---put in a magnetic drain plug

you say that you are still in the build process, meaning the engine hasn't been run much---that pushrod rocker may not of been seated in the cup correctly(with shaft rocker systems they are tricky to get all of them seated during the initial install) check others for marks around the adjuster

there is no reason to remove the heads but if you can't find pieces around the top of the head you might want to check at the corners where the oil drains back and possibly remove the manifold

If it was during a race, I would put in a new adjuster screw and pushrod and go run it

Jerry

[JRoss]

Priobe,

This sounds very similar to a problem I had a while back. I was breaking push rods and rockers at low rpm driving in traffic. Each time I took it back to the builder he blamed me for abusing the engine. What it turned out to be is the builder did not have enough clearence where the push rod goes thru the manifold. I had many pushrods that were touching the manifold. This was causing sideways pressure on the pushrods which ended up breaking many pushrods, rockers and it also broke 2 lifters.

George Anderson wrote a good article on this problem
http://www.gessford.com/projects/feintakes.htm

Dont know if this is your problem but it is worth taking a look at.

Good luck
John

[priobe]

Thanks guys for the feedback.

I just got off the phone with Dove. To my surprise the rocker is going to set me back only 25 dollars . I spoke to Earl at Dove and he explain the same thing what Jerry mentioned with the Smith Brothers push rod sometimes the rocker adjustment screw does not sit all the way in the cup portion. He also told me to lap the ajustment screw with the push rod to make a good fit.

I will drain the oil and cut open the filters. Believe it or not there was hardly any filings on the rocker/head. I think I might drop the pan for further inspection.

Does anyone know the phone number for Smith Brothers Push Rod.

[CJ428CJ]

I'd also suggest double checking your valve springs. Make sure the springs aren't binding at maximum lift.

Chris

[Jerry Clayton]

Smith Bros. Pushrods
62958 Layton Ave. Suitte 4
Bend Oregon 97701
tech 541-388-8188

WWW.pushrods.net


Jerry

[Scufty]

RON 61 I very much respect your opinion but tear down the engine? Wow....I mean I guess that is the "best" thing to do but there really should be no reason to have to go to that extent...I too would drain your oil and check for parts. Try to make sure you have as many of the parts that you feel are missing and then flush down the oil drain backs and fire her up! Just my humble opinion...

[priobe]

Gentlemen,

I have spoken to all parties involved in my situation. This explanation seems to be the most logical conclusion.

Using the Dove rockers, Smith Brothers Push Rods, and Edlebrock heads you really have to pay close attention when marring these parts together. In my situation it has came to the conclusion that the rocker arm adjustment screw did not sit completely inside the cup of the push rod. This resulted in a broken cup on the push rod because all the pressure did not sit inside the cup but rather on the inside edge of the cup. Almost like trying to push a baseball into a coffee cup.

Solution/tip to look for:

Remove rockers and look at the bottom of the adjustment screw. If the motor has mileage you should see on the adjustment screw, solid silver impression where the push rod was making contact. If you see a silver ring with a black center, then the adjust screw is not make complete contact and can result in a broken cup on the push rod.

1. Take the adjustment screw out of the rocker and place on the end of a drill or lathe. Apply valve grinding compound to the tip of the screw and lap the push rod cup to the screw. Continue to do this until they it is seated completely.
2. Label the adjustment screw to that push rod.
3. Wash parts thoroughly and replace in motor.