[LBL]

Should I use new head, intake, and pan gaskets or will I be okay using the originals ? The motor only has about 1/2 hr. on it but it has been assembled for about 6 months.

[67Mustang Al.]

Originally Posted by LBL

Thanks for the reading, as much as I am disapointed, at least I know what the problem is and can move forward to fix it. This is my first engine rebuild and I was quite happy that I had no leaks, or knocks and it fired right up so as soon as I get those pistons out and fix the problem, I should have a good strong running engine. If it is just a couple of rings in upside down, am I okay flipping tham or should I use new rings on those pistons? Thanks again

If it is upside rings , turning them over may not fix your problem. It could be a combination of two or three issues which will need careful measurement with engine shop micrometers and gauges.
Factors which may also be your problem are.
1. standard cylinder..... glazed bore.
2. standard cylinder.....bore shape is oval rather than round.
3. rebored.......+ 030 etc.....-poor hone ( wrong grit or hone angle).... cylinder still has boring marks in it.
4 excessive piston to cylinder clearance
5 incorrrect ring set for your application.
When you pull it down as its your first build ,it would be well worth a trip to an engine rebuild shop to have it measured.
Putting it back together the second time to have the same problem would do your head in.
Al.

[67Mustang Al.]

Originally Posted by 67Mustang Al.

If it is upside rings , turning them over may not fix your problem. It could be a combination of two or three issues which will need careful measurement with engine shop micrometers and gauges.
Factors which may also be your problem are.
1. standard cylinder..... glazed bore.
2. standard cylinder.....bore shape is oval rather than round.
3. rebored.......+ 030 etc.....-poor hone ( wrong grit or hone angle).... cylinder still has boring marks in it.
4 excessive piston to cylinder clearance
5 incorrrect ring set for your application.
When you pull it down as its your first build ,it would be well worth a trip to an engine rebuild shop to have it measured.
Putting it back together the second time to have the same problem would do your head in.
Al.

last three pages.

[LBL]

I guess I won't know what the problem is until I pull it apart but for now I am assuming that I put the rings in upside down on those 2 cylinders. I think I had a pretty good cross hatch when I honed the cylinders out, they didn't need to be bored because when I measured them initially they were all within the allowed tolerance for the engine. i was planning on pulling the intake and exhaust off as well as the head and pan and pushing the pistons out the top without taking the motor out so I can't take it to a shop. If I find that the rings were orientated properly, I might then decide to pull the block and get it measured again. If the rings are in upside down, then I think I'll rehone those 2 cylinders and put new rings in ( the right way ) and put it back together. Do you think I will need to get new gaskets ?

[67Mustang Al.]

Originally Posted by LBL

I guess I won't know what the problem is until I pull it apart but for now I am assuming that I put the rings in upside down on those 2 cylinders. I think I had a pretty good cross hatch when I honed the cylinders out, they didn't need to be bored because when I measured them initially they were all within the allowed tolerance for the engine. i was planning on pulling the intake and exhaust off as well as the head and pan and pushing the pistons out the top without taking the motor out so I can't take it to a shop. If I find that the rings were orientated properly, I might then decide to pull the block and get it measured again. If the rings are in upside down, then I think I'll rehone those 2 cylinders and put new rings in ( the right way ) and put it back together. Do you think I will need to get new gaskets ?

Sounds like you have a plan there. You could probably reuse the exhaust gaskets if they separate without tearing. If they leak its not a big job to replace them but if your intake gakskets leak then that is more difficult. As they are crushed on assembly to fit any suraface imperfections, when they are reused they may leak around the water jackets on the ends. When i assembled my 347 i smeared a thin layer of hi-tep rtv silicone around the water jackets. Personally i would put new intakes on.
One thing is for sure you are getting close to the problem .Keep on diggin. If you think you have the problem, get a second opinion from your local engine building shop.
Al.

[cobalt327]

Originally Posted by LBL

Do you think I will need to get new gaskets ?

Yes. It is almost impossible to remove the heads w/o tearing the head gaskets. There are some MLS head gaskets that reportedly can be reused (on the same head, same side "up"), but if they tear or delaminate at disassembly I would not reuse them, or any head gasket w/the exception of a copper gasket.

Same thing for the intake gaskets. The rest of the gaskets all are paper (except possibly the exhaust gaskets), so if they tear, replace them. I will reuse valve cover gaskets if they don't tear. The rear main and timing cover seals can be reused as long as they're not damaged somehow.

If you used the rubber rail intake seals, toss them and run a bead of RTV instead.

[LBL]

Man, I haven't really had a lot of time to work on the engine but I have got one piston out and it looks okay as well as the rings. I think I put the ring that should be on top in the second land and the ring that should be in the second land in the top land. Would that be enough to cause a drop in compression and the crankcase to pressurize ? I am thinking that I will find this on the other piston that had poorer compression as well.

[dsraven]

one other thing to make sure of is the ring end gap position when you put it back together (and, for curiosity, when you take it apart. just to see how they were lined up). make sure the gaps aren't all in a row, one below the other, and if you have a 3 pc oil ring make sure to stagger the oil ring top and bottom rails as well so they don't line up. check the box that the rings come in-there is usually directions on gap placement and which side of the piston to place the gaps-thrust side or not. remember to check the gap at the top and the bottom of the bore. that will also give you an indication of bore taper as well. make sure to deglaze the cylinders before installing new rings. did you remove the ridge from the top of the bore when you did your prep work? when you originally did the engine bore check, what was the bore taper and piston clearance? within spec? what was the ring end gap for each ring? within spec? how did you place the ring end gaps? on assembly make sure to install the rings squarely so they don't bend out of their flat plane. ring expanders are cheap if you don't already have a set.a ring compressor is an important tool for assembly as well, so the rings don't get bent or a piston ring land gets damaged.
as far as gaskets, you should bite the bullet and use a new set. you don't want to have a leak and have to pull it apart again, or worse yet, have coolant leak into a cylinder and hydraulic lock the engine or leak into the oil and wash out a bearing too. cheap insurance.
if you haven't done so already, make sure to cover the ends of your con rod bolts (with a piece of hose if nothing else) when you drive that piston out. otherwise you risk the bolt marking your crankshaft on it's way past.
just some thoughts, hope it all works out for you.

[LBL]

I can't see anything wrong with the rings or the cylinders, would it be possible that I didn't hone those 2 cylinders enough, would that be enough for the rings not to seat? I really don't want to put it back together without a glimmer of hope that I have fixed the problem. I have new gaskets, you were right, not a chance in hell that the old opnes could be reused.

[rusthater89]

Did you actually measure the bores? A good tool to use is a set of telescoping gauges.

[67Mustang Al.]

Sounds as if you have honed the cylinder with a diy spring -loaded unit. Were the bores checked for roundness before you honed. If the bore was out of round before you honed then the only way to get a concentric bore back is for a machine shop to do it.
Standard bore or rebored.If you dont have the telescoping bore gauges then you should try to get someone from the machine shop to come out and measure your cylinder diameter using their dial gauges, if the engine is still in the car. ????

[LBL]

The engine is still in the car, I figured it would be easier to just pull the pan and work on it in the car, that may not have been the easiest way in the end. nayways, I'm back from a lillte vacation and I'll be working on it again tomorrow. I would rreally like to have it running before I have to put it away again for winter so I'll try to get someone to measure the bores in those 2 cylinders.

[LBL]

This is what I have so far. I checked the bore of the cylinders and found that they were both pretty much the same. The bore from front to back is : top 3.999, middle 4.008 on one and 4.023 on the other one. The bottoms were 3.996, and 3.999. The side to side bores are 3.998 at the tops and 4.004 in the middle and at the bottoms. The ring end gaps are ; top .020, middle.018 and bottom .016 and that's both cylinders. I am thinking that they aren't out of round and I just need to hone them a bit more thoroughly and make sure the new ring gaps are opposite to each other on the pistons and I should be okay . The pistons appear perfectly round and are 3.972. What are your thoughts ?

[cobalt327]

Originally Posted by LBL

This is what I have so far. I checked the bore of the cylinders and found that they were both pretty much the same. The bore from front to back is : top 3.999, middle 4.008 on one and 4.023 on the other one.

Unless you are missing a "0" to the right of the decimal point, there's no way this'll work.

[LBL]

Thanks for noticing that, there should be another 0 in there, I'll go back in and change it ..thanks ,,, looks like I can't get in to edit that post so I'll have to leave it but it was 4.0023..