The Ford Barn

Bored&Stroked · 10-24-2019, 07:16 AM

Quote:

Originally Posted by mrlaser

Another view.

Good Imagineering! I used a little "tool" I made on my lathe - on my drill press (pushes the retainer down so I can put the keepers in).

mrlaser · 10-24-2019, 12:12 PM

Thanks so much for the comments and suggestions. I will double check for the correct timing of the valve movement later today. I do have the necessary lubricants on hand and will be using them as things progress.

mrlaser · 10-24-2019, 01:02 PM

The valve movement was exactly as described. When reassembling the top end, would it be ok to place one head on without the intake to assess the compression on that side ? I certainly hope that there will be a significant improvement, but would like to see some actual numbers before reassembling everything. As has been suggested, I do plan to do a preliminary check on the sealing of the intake valves by using a shop vac on the intakes. Since the engine is in the car with an exhaust system installed, i'm not sure about doing that test on the exhaust valves. Any thoughts or suggestions would be greatly appreciated.

Bored&Stroked · 10-24-2019, 01:42 PM

If you're seeing a good solid "lapping" area on the valves/seats, you really should be good to go. I would blue die-chem (or magic marker) the seats as well - just to make sure that the seat has a really nice lapped area (that there is no issues with out of round or other sealing conditions).

On the intake side, I've turned the stand such that the deck is parallel to the ground (down) and poured a little lacquer thinner into the port (use a syringe) - then you can look on the chamber side of the valve for any weeping around the valve. If you find one, just use fine lapping compound and do it again - until none are weeping.

You can do similar tricks on the exhaust - is just a bit more of a pain to do . . . so the vacuum cleaner might be your friend.

Good luck!

mrlaser · 10-24-2019, 03:43 PM

I did do the Magic Marker on all the seats. The marker was removed with a few turns of the valve lapping stick.

Fortunately,or unfortunately the motor is in the car, not on a stand. That is the rationale for the shop vac and something like PB Blaster to check for leaks. I suppose that I could connect the vacuum to the tail pipe on each side to do the exhaust side. Thanks again for your Imput.

Bored&Stroked · 10-25-2019, 10:00 AM

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Me, I'd not want to pull a bunch of solvent onto the tops of the valve guides - might remove lubrication of the valve stems (just thinking out loud here). So I would trust my lapping and not worry about the vacuum cleaner.

JSeery · 10-25-2019, 10:29 AM

I'm with B & S here, don't really think the vacuum cleaner is going to tell you much on anything. If the valves are assembled correctly and seating correctly it should be good to go. If not I would thank removing the intake (and even the heads if it is required) would be less effort than trying to rig up a test using a shop vac.

Desoto291Hemi · 10-25-2019, 04:35 PM

The lapping looked very good to me,,,,a nice even pattern,,,centered in the valve face too.
Good job.

Tommy

mrlaser · 10-25-2019, 07:29 PM

Actually the heads and intake are still off while I check the valve lash. Thanks for all the help. I will post a follow-up when the engine is back together (and running...I hope)

AnthonyG · 10-26-2019, 10:53 AM

Im not an expert on Flattys for sure, done the normal pull plugs replace & tune it up. I e had many Mid ‘60’s GM engines apart & think after building startup should happen right after rebuild to seat everything, more time unstarted amplifies w Unstarted new rebuild low compression is possible until seating internals. That one left the garage so try this before disassembly. Drain a quart of oil & replace w STP poured equally in each spark plug holes & turn the engine over letting STP coat cylinders & rings. Lightly Redress plugs w point file reset & Replace plugs, prime carb w fresh gas (have fire extinguisher handy) no ethanol if possible & see if she fires up. If so if all sounds good don’t shut it down & let run for 30 or so minutes. STP should give compression a boost needed to more easily start as long as if as stated all setup right when built.

mrlaser · 10-26-2019, 12:26 PM

Currently the engine is still at the short block stage. When I am ready to try to start it, I will be changing the oil. As suggested, I will add a qt of STP at that time. Thank you for your help.

AnthonyG · 10-26-2019, 01:39 PM

Don’t forget, put STP in spark plug holes last & crank engine quickly after, sequence important to insure distribution of STP on rings & cylinder just before trying to start. BOL

mrlaser · 10-26-2019, 05:21 PM

Will do. Thanks again.

mrlaser · 11-08-2019, 11:19 AM

Update: I have adjusted all the lifters to the recommended settings. As mentioned before, all the valves have been lapped. After reinstalling the right side head, I repeated the compression test. All 4 cylinders were improved but still low at 65#. Added oil brought this up about 5#. ( this engine has never been started since the complete rebuild)The intake is still off so I verified that the valve lash was correct when the leak down device was functioning. The leak down test indicated that all the leak was from the individual intake valve oriface in the block.. I have no idea which valves were used in the rebuild. Is it possible that the valves aren't entirely seating because the stem is being held up slightly in the guide? The intake and exhaust valves are all identical and are stainless steel. Not sure what to do next. Help.

mrlaser · 11-08-2019, 11:24 AM

I should mention that I lapped the valves with the guide in place but without the clip in place to make the guide depth consistent. That might explain why the lapping was accomplished. When the valve lash adjustment was done it was the assembled valve unit in place with the clip installed.

flatjack9 · 11-08-2019, 11:28 AM

Were all of the intakes leaking?

mrlaser · 11-08-2019, 11:38 AM

well, I have only tested the 4 valves on the right side of the engine, all of them were leaking about 60% on the leak down gauge.

mrlaser · 11-08-2019, 11:44 AM

I am wondering whether lapping without the clip in place might have masked the fact that the valve might actually be hanging up once the valve unit was clipped in it's proper position. In other words since the guide was not in a fixed position, if was free to move to whatever depth was necessary for the lapping to be accomplished.

40cpe · 11-08-2019, 01:01 PM

I think you might be on to something. If the guide is interfering with the valve, it can't be much. I thought about driving the guide down without the spring and see if the clearance changes, but probably not enough to measure. I think I would try removing about .005-.010 from the top of the guide. You might do some close measuring on one of the valves from the side with the head off.

mrlaser · 11-08-2019, 02:09 PM

Actually, I pulled the head on the right side and removed the #1 intake valve unit. The mid stem measures 0.342 while the area immediately above the guide measures 0.344. Above that there is a suggestion of a shoulder and the stem tapers up into the valve head. Pushing down on the valve head to compress the spring results in the valve stem becoming "wedged"in the guide opening. It seems that this might prevent the valve from seating properly once the clip is put in place with the resultant spring compression. Any other thoughts or suggestions would be appreciated. Thanks everyone for your help.

10-24-2019, 12:12 PM	#42
mrlaser Senior Member Join Date: Sep 2019 Location: Savannah, Ga Posts: 225	Re: 8BA compression issues Thanks so much for the comments and suggestions. I will double check for the correct timing of the valve movement later today. I do have the necessary lubricants on hand and will be using them as things progress.

10-24-2019, 01:02 PM	#43
mrlaser Senior Member Join Date: Sep 2019 Location: Savannah, Ga Posts: 225	Re: 8BA compression issues The valve movement was exactly as described. When reassembling the top end, would it be ok to place one head on without the intake to assess the compression on that side ? I certainly hope that there will be a significant improvement, but would like to see some actual numbers before reassembling everything. As has been suggested, I do plan to do a preliminary check on the sealing of the intake valves by using a shop vac on the intakes. Since the engine is in the car with an exhaust system installed, i'm not sure about doing that test on the exhaust valves. Any thoughts or suggestions would be greatly appreciated.

10-24-2019, 01:42 PM	#44
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,062	Re: 8BA compression issues If you're seeing a good solid "lapping" area on the valves/seats, you really should be good to go. I would blue die-chem (or magic marker) the seats as well - just to make sure that the seat has a really nice lapped area (that there is no issues with out of round or other sealing conditions). On the intake side, I've turned the stand such that the deck is parallel to the ground (down) and poured a little lacquer thinner into the port (use a syringe) - then you can look on the chamber side of the valve for any weeping around the valve. If you find one, just use fine lapping compound and do it again - until none are weeping. You can do similar tricks on the exhaust - is just a bit more of a pain to do . . . so the vacuum cleaner might be your friend. Good luck!

10-24-2019, 03:43 PM	#45
mrlaser Senior Member Join Date: Sep 2019 Location: Savannah, Ga Posts: 225	Re: 8BA compression issues I did do the Magic Marker on all the seats. The marker was removed with a few turns of the valve lapping stick. Fortunately,or unfortunately the motor is in the car, not on a stand. That is the rationale for the shop vac and something like PB Blaster to check for leaks. I suppose that I could connect the vacuum to the tail pipe on each side to do the exhaust side. Thanks again for your Imput.

10-25-2019, 10:00 AM	#46
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,062	Re: 8BA compression issues Sponsored Links (Register now to hide all advertisements) Me, I'd not want to pull a bunch of solvent onto the tops of the valve guides - might remove lubrication of the valve stems (just thinking out loud here). So I would trust my lapping and not worry about the vacuum cleaner.

10-25-2019, 10:29 AM	#47
JSeery Member Emeritus Join Date: Nov 2012 Location: Wichita KS Posts: 16,132	Re: 8BA compression issues I'm with B & S here, don't really think the vacuum cleaner is going to tell you much on anything. If the valves are assembled correctly and seating correctly it should be good to go. If not I would thank removing the intake (and even the heads if it is required) would be less effort than trying to rig up a test using a shop vac.

10-25-2019, 04:35 PM	#48
Desoto291Hemi Senior Member Join Date: Oct 2019 Location: Carthage , Tennessee Posts: 199	Re: 8BA compression issues The lapping looked very good to me,,,,a nice even pattern,,,centered in the valve face too. Good job. Tommy

10-25-2019, 07:29 PM	#49
mrlaser Senior Member Join Date: Sep 2019 Location: Savannah, Ga Posts: 225	Re: 8BA compression issues Actually the heads and intake are still off while I check the valve lash. Thanks for all the help. I will post a follow-up when the engine is back together (and running...I hope)

10-26-2019, 10:53 AM	#50
AnthonyG Senior Member Join Date: May 2013 Location: Pa. Posts: 2,164	Re: 8BA compression issues Im not an expert on Flattys for sure, done the normal pull plugs replace & tune it up. I e had many Mid ‘60’s GM engines apart & think after building startup should happen right after rebuild to seat everything, more time unstarted amplifies w Unstarted new rebuild low compression is possible until seating internals. That one left the garage so try this before disassembly. Drain a quart of oil & replace w STP poured equally in each spark plug holes & turn the engine over letting STP coat cylinders & rings. Lightly Redress plugs w point file reset & Replace plugs, prime carb w fresh gas (have fire extinguisher handy) no ethanol if possible & see if she fires up. If so if all sounds good don’t shut it down & let run for 30 or so minutes. STP should give compression a boost needed to more easily start as long as if as stated all setup right when built. __________________ Nomad

10-26-2019, 12:26 PM	#51
mrlaser Senior Member Join Date: Sep 2019 Location: Savannah, Ga Posts: 225	Re: 8BA compression issues Currently the engine is still at the short block stage. When I am ready to try to start it, I will be changing the oil. As suggested, I will add a qt of STP at that time. Thank you for your help.

10-26-2019, 01:39 PM	#52
AnthonyG Senior Member Join Date: May 2013 Location: Pa. Posts: 2,164	Re: 8BA compression issues Don’t forget, put STP in spark plug holes last & crank engine quickly after, sequence important to insure distribution of STP on rings & cylinder just before trying to start. BOL __________________ Nomad

10-26-2019, 05:21 PM	#53
mrlaser Senior Member Join Date: Sep 2019 Location: Savannah, Ga Posts: 225	Re: 8BA compression issues Will do. Thanks again.

11-08-2019, 11:19 AM	#54
mrlaser Senior Member Join Date: Sep 2019 Location: Savannah, Ga Posts: 225	Re: 8BA compression issues Update: I have adjusted all the lifters to the recommended settings. As mentioned before, all the valves have been lapped. After reinstalling the right side head, I repeated the compression test. All 4 cylinders were improved but still low at 65#. Added oil brought this up about 5#. ( this engine has never been started since the complete rebuild)The intake is still off so I verified that the valve lash was correct when the leak down device was functioning. The leak down test indicated that all the leak was from the individual intake valve oriface in the block.. I have no idea which valves were used in the rebuild. Is it possible that the valves aren't entirely seating because the stem is being held up slightly in the guide? The intake and exhaust valves are all identical and are stainless steel. Not sure what to do next. Help.

11-08-2019, 11:24 AM	#55
mrlaser Senior Member Join Date: Sep 2019 Location: Savannah, Ga Posts: 225	Re: 8BA compression issues I should mention that I lapped the valves with the guide in place but without the clip in place to make the guide depth consistent. That might explain why the lapping was accomplished. When the valve lash adjustment was done it was the assembled valve unit in place with the clip installed.

11-08-2019, 11:28 AM	#56
flatjack9 Senior Member Join Date: May 2010 Location: Oshkosh, Wi Posts: 4,526	Re: 8BA compression issues Were all of the intakes leaking?

11-08-2019, 11:38 AM	#57
mrlaser Senior Member Join Date: Sep 2019 Location: Savannah, Ga Posts: 225	Re: 8BA compression issues well, I have only tested the 4 valves on the right side of the engine, all of them were leaking about 60% on the leak down gauge.

11-08-2019, 11:44 AM	#58
mrlaser Senior Member Join Date: Sep 2019 Location: Savannah, Ga Posts: 225	Re: 8BA compression issues I am wondering whether lapping without the clip in place might have masked the fact that the valve might actually be hanging up once the valve unit was clipped in it's proper position. In other words since the guide was not in a fixed position, if was free to move to whatever depth was necessary for the lapping to be accomplished.

11-08-2019, 01:01 PM	#59
40cpe Senior Member Join Date: May 2010 Location: Star, MS Posts: 4,024	Re: 8BA compression issues I think you might be on to something. If the guide is interfering with the valve, it can't be much. I thought about driving the guide down without the spring and see if the clearance changes, but probably not enough to measure. I think I would try removing about .005-.010 from the top of the guide. You might do some close measuring on one of the valves from the side with the head off.

11-08-2019, 02:09 PM	#60
mrlaser Senior Member Join Date: Sep 2019 Location: Savannah, Ga Posts: 225	Re: 8BA compression issues Actually, I pulled the head on the right side and removed the #1 intake valve unit. The mid stem measures 0.342 while the area immediately above the guide measures 0.344. Above that there is a suggestion of a shoulder and the stem tapers up into the valve head. Pushing down on the valve head to compress the spring results in the valve stem becoming "wedged"in the guide opening. It seems that this might prevent the valve from seating properly once the clip is put in place with the resultant spring compression. Any other thoughts or suggestions would be appreciated. Thanks everyone for your help.