Fired it up tonight

[Anonymous]

Pushed and pushed to get through this weekend before my brother left. We worked on it until 11pm last 3 night's, started at 7am today and finally fired it up at 7pm tonight. Set the timing, ran great for almost 20 minutes at 2000 rpm, then this;

I can't think straight at this point. Plug is from #6. Just can't believe I have to start over. Any idea's what happened? The shop that did the rebuild is supposed to be a good one.

Don

 

[Anonymous]

Do they all look like that or just number 6? How much did you mill off the head and/or deck the block? What are they gapped to?

 

[MustangSix]

It looks like a nut or screw fell into the cylinder. If you pull the head, you may have caught it soon enough to catch the damage.

 

[Anonymous]

A moment of silence............................
.....................................................................
.......................................................................
.........................damn

 

[rbohm]

8) i agree with jack. it sure looks like something was rattling around in that cylinder.

it is head pulling time.

 

[Anonymous]

he said it ran great for 20 min at 2000 rpm. I dont know about you but wouldnt a nut or screw be loud bangin around in a cyl. like that? pull the head of course....but oke.......did you hear it after the 20 min u had it running? or did u not hear it at all?

 

[addo]

It's not a ring. It's something hard, and large enough to bend the electrode first. Possible are a piece of valve, a seat if fitted (likely), or a countersunk headed screw. Do you have young children? They like to help.

AS RB said, likely it hasn't done too much. I expect resurface the piston - if needed - and head repairs as required. You'll get there.

Adam.

 

[Anonymous]

Hey I am back from the dead...slept straight through, it was a big day. All the other plugs look fine. It is possible something fell into the hole. Our children know not to come within 50 yards of where we are working as they would be made to help also the youngest is 15. The shop pulled the 170 and rebuilt and intalled the 200. There were no plugs in the car when I picked it up. As to the noise, when we first tried to start the engine the starter was not disengageing, this makes a terrible noise. We shimed the starter out with some washers and it cranked right up. Sounded good, was a little rough but the was no ratteling. The exhaust had been out on the day before as we wanted to hear the engine when it first ran. My brother said dropped valve, all we can see looking in is scratches where it looks as if the plug dug into the top of the piston. The OZ head was gone over only lightly, there was no milling done. The only thing I can think of is that during the rebuild he discovered the rocker arm and pushrods would not work and he used the ones from the old engine. Something about the way the rods were shaped on top. My only thought about that was I would have had him use the adjustable rocker arm from the 170 had I known he was changeing it.

Don

PS. the rebuilt C5 will not allow the car to roll backward in neutral. We had hoped it would correct itself once pumped up but I never even got to put it in gear. Well I'm off to disconect the driveshaft again and load it onto the trailer. I'll see what the machinist says tommorow.

 

[Anonymous]

The engine was running well, then all of a sudden it began to run rough as if it lost one or more cylinders, at that time there was also a rattling noise. My brother told me to take out the plugs as he wanted to check the compression but when I got to 6...

Don

 

[addo]

All that points to a dropped seat. The wrong pushrods would prevent it from running well to start with. And the plug will never contact the piston unless something is terribly wrong with the bottom end. The assembled height across the tips of the valve stems may proffer a clue.

Adam.

 

[Anonymous]

I did not have the hardened valve seats installed. As far as I know he just went over it lightly. These heads are supposed to be bolt on modifications. My brother thinks the problem came in when he changed the rocker arm and pushrods. That the pushrods were too long and when pumped up fully put too much stress on the valve.

Is there additional information that I should have given him? I guess I need to know if there anyway that I am at fault.



Also when I say the engine ran well I mean it was running on all cylinders. It was a little rough but I expected that until we got the timing dialed in and the carb adjusted.



It was not making any unusual sounds but neither was it as smooth as a properly adjusted engine would be.



I know I will have to wait to hear the diagnosis. But I want to make sure I get it done right his time. Also I guess I now have the opportunity to do those things I learned after it was through. Maybe change the cam a little, hardened valve seats, use the steel head gasket, do this blocking and milling you guys talk about.



What should I have done to the head provided it is repairable?

 

[Mustangaroo]

Don,
For sure do the Hardend exhaust valve seats, have your machinest install the Clifford port divider, 3 angle valve cut, have your head cc'd, my heads are 46cc (been milled a bunch) my sons are 56cc but depending on your deck height, mine .025 my son's .000 (decked) and your gasket thickness you'll know your Compression Ratio, don't forget to measure the dish in your pistons as this is part of your CR's. You'll want a 9:1.1 to 9:5.1 ratio for good performance. If your running a C4 trans keep the stock cam or go a mild grind with high valve lift, if you have a 4 or 5 speed you can run a much bigger cam. Also keep a extra set of intake gaskets around, I have found after running 1K or 2K in the heat the gaskets are hard and if re-used you'll get a intake leak which will result in hard starting, rough idle and back fireing. I just got a sheet of gasket material and cut my own now!

Good luck!

 

[Anonymous]

Machinist called, asked if I could come down...

Showed me the damage...

and the cause...

the valve seats have already been done and he doesn't think much more, if any, could come off the head as it has been done too.

looks like a lock washer...musta been stuck in the intake somehow and come loose.

 

[Anonymous]

Don, That’s a damn shame,

What's your next step? What is your mechanic recommending? Is he accepting any responsibility or is it all on you? Looking at the pics, it looks like you have damage in more than one hole. If the pitting isn't too deep you may be able to burnish out the high spots and reassemble. I'm not sure what the depth tolerance would be on such damage. Anyone want to hazard a guess?

 

[Anonymous]

Yeah, the damage was mainly to #6, looks like the washer hit there came apart and a piece of it ended up embeded in #1. This is a family owned shop who I have dealt with for years, they are honest and reliable. The guy who built the motor is good, this is the second one he has done for me. They are willing to go in whatever direction I want. I just don't think he did anything wrong. I took delivery of the car without the intake attached. It sat in my brothers garage for 2 months while I tried in vain to get a header to fit it. The washer could not have been in there the whole time because when it hit we all heard it. It had to be stuck in the intake or dropped down the carb,which I installed.

I asked him what he thought I should do. He said smooth it up as much as possible, slap the head back on, and drive the H E double L out of it. When I went back in 3 hours he had it running and was adjusting the carb. The turbo muffler sounded real good. I smiled, I think I got off lucky. I miss my baby, I hope to drive her home tomorrow.

Don

 

[ruckus68]

what are the cc's of your head chaimbers? Maybe he can do just a clean up skim of the head or you can take a flap wheel and polish it a bit to get rid of the high spots. Looks like that piston is done also

that really sucks man. i feel for you

John

 

[alloydave]

Sorry to read about your troubles , i hope everything goes smoothly when it goes back together . Man i know what it feels like when you suddenly discover a problem on start up . I pulled the dizzy on my crossflow after about 2 hours of running to find it had chewed the gear up pretty bad and filled my sump with nice little metal bits , and i think i bore washed it too. These things are sent to test us . Im sure when its going again and your
cruising and enjoying your pride and joy these kind of things will only seem like a small set back .Hang in there mate ,think of those sunny days ,sun glasses on , stereo turned up , your lovely lady by your side and all those people staring at your car saying what a sweet ride .

cheers dave

 

[MustangSix]

Judging from the pics, I'd say you got lucky.

I agree with the machinist....put it back together and drive it. The valves are ok, the piston is dinged but not broken, and a few dings on the quench surface won't make a difference. At most, I might replace the piston, but it doesn't look like that's necessary.

Remember, this ain't no 7500 rpm screamer.....it'll be just fine in the reve range these engines normally reside.

 

[addo]

The head will clean up fine; it's not been cut much compared to some. If the cc's end up too high, lay back the chamber edge near the inlet. A new piston will be a good idea, but possibly the same rings.

Check the valves and pushrods for true, and the rocker faces for damage.

It just got its initiation tatts. Nothing more.

Adam.

 

[Anonymous]

Sorry to dredge this back up but I need advice. I have had no luck geting my header to seal, just lost gasket #3. Each time the leak is at the top of 3/4. When installing the last gasket I noticed the iron had eroded a bit on the head at this same locatin. Evidently it has leaked awhile in the past. My plan now is to pull the head, have the port divider installed so there is more meat to clamp too, and get the exhaust surface trued. Is this doable?

Also while I have the head out I intend to have it cc'd and target a 9.1 compression ratio. Someone pointed out, based on the pictures, that hardened valve seats had been installed. This was done prior to my receiving the head, I don't think the machinist did anything to it, although he said he looked it over. So can a 3 angle valve job be done with the existing valves? Should I get Mike to send me the new ones. Are metal headgaskets still available? Do I measure deck height from the top of the piston?

BTW, we did replace #6.


Thanks,
Don