Well I think I messed some thing up here. I have a 351m modified to the hill. Completly rebuilt,aussie heads,borded,performer intake etc. (check my gallery for complete list). Here is the problem, after starting the eng for the first time after rebuilding it ran fine,then started to miss on #6 cyl. I pulled the valve cover the bolt the holds the rocker arm on the exhaust valve was broken off.. It looked to me that there was not a lot of oil on the rocker arms and through the head. After starting the eng for the first time I checked oil pressure and it was about 3/4 on the stock dash oil pressure guage.Were do I start after I remove the broken bolt. If you refer to one of my previous posts I have an oil leak between the block and Performer 400.
I also have put in a high vol oil pump, during the rebuild. Well did I mess somthing up? I understand the oil for the rocker arm come via the pushrods from the lifters. If I have good oil pressure the oil should be flowing up on the rockers and makeing a big mess. Thanks Art

 

[updated:LAST EDITED ON 17-Sep-02 AT 05:27 PM (EST)] NO I don't think you goof up on anything, More then likely you lucked out and have a set of heads that lets the oil flow back down to the pan faster then you can get the valve covers off.
OK here's what I'd do, get the broken bolt out and replace it with a new one then before you put the valve cover back on start it up and see how much oil is making to the top of the rockers. At an Idle it should just dribble a little out of each rocker. If you rev it a little it should increase some but it still will only be dribbling off the end of the rockers.

As for the Intake leak Check your oil sending unit first to make sure it's not leaking, then take the intake off and throw away those Rubber gaskets an clean up the top surfaces with brake clean and lay down about a 1/2" bead of silicon sealer and reinstall your intake, taking your finger and smoothing out the silicon on both ends before it sets.Also put it on both sides of tin gasket in that area.

 

What kind do you use (manufacturer/brand/model#)? Thanks!

 

Thanks I will let yo know what happends. Thanks ARt

 

>What kind do you use (manufacturer/brand/model#)? Thanks!

What the silicon or the gaskets????

Silicon is the good clear or black Dupont,General Electric or 3M kind.
3.99 per tube.

Gaskets I use the the top dollar Felpro Printoseal everywhere I can.
Why waste your time putting in the cheap stuff that might blow out and then you have to rework everything to replace them.

 

When you start it up with the covers up it should start to fill up to the lower lip/cover seal and will over flow there after a while. Also if you rev it a little it should sling oil all over everything. At least that's been my experience.
Also make double sure the push rod gets seated in the bottom of the lifter, it is possible to get it set on the lip and burn a valve or break something.

 

Shazam.

Guess what!! Plenty of oil to rocker arms (oil on Garage floor)I also found #5 intake push rod bent. With the rocker bolt on #6 broken and the bent push rod on #6, I am wondering what went wrong? NEW heads (Aussie),all new springs, valves,guides.pushrods and rockers.

 

>Shazam.
>
>Guess what!! Plenty of oil to rocker arms (oil on Garage
>floor)I also found #5 intake push rod bent. With the rocker
>bolt on #6 broken and the bent push rod on #6, I am
>wondering what went wrong? NEW heads (Aussie),all new
>springs, valves,guides.pushrods and rockers.

Well I guess I'll have to ask .. Did you do a clearance check of the piston to valves before you did the final assembly. Could be the pistons chasing the valves closed, or the valves are chasing the pistons down the bore. either way they seem to be making contact. (Via Bent pushrods).
Well here's what you can do to fix this problem. Have to get a multi keyed timing gear and retared the cam 2 degr. or advance it 2 degr. but either way you have to check to see how much clearance you have between the valves and pistons. With out the head gasket your looking for about .150 clearance between piston an valves.
BTW what cam are you running in this motor.

 

[updated:LAST EDITED ON 20-Sep-02 AT 08:17 AM (EST)]The answer to the question is no I did not check the clearance. I didn't think I really had to. I put in stock pistions and Aussie Heads. I thought all was the same except for the chamber size.

Last night I removed the manifold all looks good,no other bent pushrods lots of oil. Do you think I should pull the head? I think this is weird, no orher damage found. Correct me if I am wrong but the eng has run for about 2 hours total, if the valves were hitting the pistions I should see other bent pushrods. I would hate to pull the heads off! Also When I installed the cam I set it so the marks on the timing gears were matched. Not advanced nor retarted. Thanks Art

Here is my parts list:

Aussie Heads (port polished)
Stock Pistons
Bored 30 over
Crank 10 under,polished
Rings,bearings etc
Crane 272 Cam Part #133042
Edelbrock 650 (1406)
Edelbrock performer 400
MSD 6a
MSD dist
Roller timing chain
High vol oil pump
Headers
Dual exh
High flow cats
Flowmaster muffler 2 in 2 out
Griffin Radiator
C6 B/M Trans kit
B/M shift kit
B/M Megashifter
All hoses braided stainless covering
Ford Racing Valve Covers and Wing Nuts
New damper

 

OOOOOK .....
Well here's some good news ... You Don't have to pull the heads to check the clearances.

Here's what you have to do..

Get a compression tester And go the your local Ace Hardware store and get a set of low tension spring. they'll be about 1/2" in dia. and about 3" long, that what I use for this operation.
Now take the valve stem seal out of the compression tester so you'll be able to move air both ways with it.

NOw your going to do a valve spring removal with the heads on the motor, so you also have to find one of those cute little spring compressors too and Dail indacator with a magnatic base. Check with your local shops to see if you can borrow one of there's.

1.) Remove all the spark plugs .
2.) Any cylinder will work for this .
3.) Screw in compression tester and hook it up to a compressed air line, try to maintain 60 Psi in the cylinder.
4.) Remove Valve springs one at a time and put the lightweight spring on in it's place.
5.) OK to remove air pressure now.
6.) now put your push rods and rockers on just like they normally would go on.

Now set-up the dail indacator on the head with it touching the valve spring retainer. ( I use a piece of 2X2 Flat bar with a hole in it to bolt to a valvecover bolt hole) Now Turn Motor over by hand with ratchet using the bolt on the harmonic balacner to almost top dead center, Now depress spring to see if it hits piston. You'll be working from about 5 Dreg. before TDC to 10 Dreg. After TDC Look down the spark plug hole to see where the pistons at.Your looking to make sure the valves aren't hitting the piston first off, But secondly your looking to see just how much clearance you have from the piston on both valves as you go through the open an close cycle for both valves .

It could be that the heads have been milled or they have brand new valves in the heads with new seats and that will make them stick out more and really make them close. Or your cams own timing could be off a little. Your looking for numbers like .150 Ex. .120 Int.

Take your time and check it a few times on each valve to see if you get the same number each time.If you have to adjust the timing gear pulling the Dampner and front cover isn't that big of a deal.

And then Check it both ways .....Advanced and Retarted
Write all your numbers down to help you keep track.
then set it up with the one that give you the clearances I gave you above or in that nieghborhood.

Let me Know how it turns out.
ShaZam

 

These engines "usually" have a ton of valve to piston clearance unless, you have very high compression and or a big lift cam. I would check it anyway but I suspect you have bad valve train geometry. Do you have adjustable rockers? If not your push rods may be too long causing coil bind in the springs. This could also lead to burnt valves.

Good luck

 

 

Thanks for the quick responce. I looked at the proccedure you wrote, wouldn't be easier if I just bit the bullet and removed the head. Something must of really happend in order to bend a push rod like 2 upside down L's connected together and break the bolt on the next cyl rocker arm, The work that was done on the heads was a valve job(no new seats), all new valves,guides,and springs etc. Correct me if I am wrong. Everything can check ok but I will never know the condition of the piston. I would hate to put everything back together and go down the road and blow a pistion. I have a new set of head gaskets and plenty of labor. Again something must of got hung on these cyl's. If a lifter got hung would this happen? All other pushrods look ok.

Looks like I got work to do. What do you guys think!!

 

Interesting point. The cam I put in is a Crane Cam. part # 133042, Grind # 272 H10. The only thing different was I timed the cam to were both mark were aligned. Before the change I believe it was retarted from the factory. Thaks Art

 

Just got off the phone with Crane Cams. They said my problems is most likly the valve hit the piston. The possible problem is the valve retainer or the springs that were used. I have Aussie Heads, they came with no valves. The Machine shop put in new springs,valves,and retainers based on my cam info. Man I hope the rest of the valves didn't hit the pistons!! I gusee they would of if I ran it longer. Please someone tell me I am wrong. Thanks Art