| t35 | -- 03-29-2011 @ 12:34 PM |
|
i currently have the mushroom valves with solid tappets on my 35. i did a valve job 4 years ago. i'd like to put the newer valves w/ adjustable tappets and new springs. is this adviseable to do on the 35 engine? do i need to put rubber seals to stop oil consumption? thanks in advance for any info. tom
|
|
| 37RAGTOPMAN | -- 03-29-2011 @ 1:16 PM |
|
if you have good compression, there is no need to replace the valves, but if you have problems. go ahead and replace the valves with stainless steel,1 piece guides and adjustable lifters, and the seals if you want, you only need to do the intakes, make sure you do the valve seats correctly .very important if you want the valve job to last, hope this helps 37 RAGTOPMAN
|
|
| supereal | -- 03-29-2011 @ 2:06 PM |
|
There are two reasons to overhaul the valve system: poor compression and excess oil consumption. If you have the engine out and apart, the valve seats should be replaced with the new, hardened type. Old seats usually have been refaced several times, and probably don't have enough stock left to allow the proper angles. We use straight stem stainless valves, and cut extra seal grooves on the shank. Of course, one piece guides are necessary, as are new springs. We prefer self locking adjustable lifters, and we drill the bosses to allow locking the lifter to make setting clearance easier. If your '35 has poured mains, you may wish to seek an insert type block before investing in valve work. I'd do a wet/dry compression test prior to any major work.
|
|
| TomO | -- 03-30-2011 @ 9:54 AM |
|
IMHO The mushroom valves and split guides work very well when installed properly. If you need to do another valve job so soon, you should pull the engine and do a complete overhaul. Your seats are probably in bad shape, because the valve job did not last, and will have to be replaced. The straight stem 49-53 valves with the solid guides tend to have sticking problems, but do give much better oil control than the mushroom with the split guides. Adjustable lifters do not add to the quality of an overhaul, they are a convenient way to get the clearance but are usually heavier and more noisy than the stock Ford lifters. You will probably have to pay the machinist a little more to grind the valve stems for the clearance. The most important part of the decision is the qualifications of the machine shop that you select to complete the job. Take their advice, because that is where their experience and expertise is. Tom
|
|
| t35 | -- 04-03-2011 @ 9:41 AM |
|
will the oil seals fit the mushroom valves? my only big problem right now is i believe the oil is being sucked in through the valves. tom
|
|
| supereal | -- 04-03-2011 @ 10:53 AM |
|
If you have an oil comsumption problem beyond the usual, it is doubtful that intake valve seals would help much, if any. Determine whether it is valves, or stuck/worn piston rings by running a compression check on each cylinder, then squirting some oil in each and comparing the readings. If the compression rises considerably when the oil is added, rings are at fault. If not, the valves, and probably the seats, are the culprit. We do a "blowdown" where compressed air is placed in the cylinders and the loss is measured. Most home shops don't have this equipment, however. I agree with Tom that mushroom valves will work just fine, but unless you have a valve grinding machine to cut the stems, adjustable lifters will be needed. They have the additional advantage of being able to be reset if you have a noisy valve. Most of us who have done it the old fashioned way almost always end up with at least one noisy one in spite of great care.
|
|
| TomO | -- 04-04-2011 @ 8:10 AM |
|
Unlike the overhead valve engines, the Ford Flathead engines usually do not suck enough oil past the valves to make much of a difference in oil burning. The valve stems and guides get their oil from splash in the valley in the block below the intake. Excessive oil burning in flatheads is usually due to worn rings or excessive clearance between the piston and cylinder walls or oil diluted by gas from a leaking carburetor. Tom
|
|
| supereal | -- 04-04-2011 @ 10:38 AM |
|
The later 8BA engines do have stem seals on the intakes. We cut an extra groove to double the seals. Any oil that escapes via the guides is sucked upward by the vacuum created during the intake stroke, and result in deposits. The early split guides didn't have seals because the path between the halves provided a path in addition to the valve stems themselves. We like the stainless steel valves because they tend to stay cleaner in lightly driven engines, reducing the possibility of sticking.
|
|
| 34billct | -- 04-04-2011 @ 6:55 PM |
|
Check to see if oil baffle part # 48-6524 is installed in valve chamber, if it is missing it will burn oil.
|
|
| t35 | -- 04-10-2011 @ 7:17 AM |
|
how does the absence of this baffle cause oil consumption? what is its purpose?
|
|
| supereal | -- 04-10-2011 @ 11:06 AM |
|
The baffle (actually two) distributes the oil more or less evenly across the valley to provide lubrication to the valve assemblies as it emerges from the gallery fed at the front of the block that also oils the camshaft. If omitted, or out of place, the oil can spurt and splash in the chamber, allowing some guides to be over oiled, increasing loss, while others receive less lubrication.
|
|
| EFV-8 Club Forum : | https://www.earlyfordv8.org/forum |
| Topic: | https://www.earlyfordv8.org/forum/viewmessages.cfm?Forum=18&Topic=2831 |