My continuing saga!

I noticed that on my rocker arm all the adjustment screws are out all the way. What would cause that?? I have run different scenarios thru my little brain and nothing seems to make sense! I seem to have the correct pedistals. I don't see how lifters and pushrods could get mixed up! There only seems to be 2 different types and there is a huge difference. Somebody suggested that maybe it is a re-ground cam, but I thought they built them up first and then reground to original specs!! Oh, I do not remember if it is re-ground or not, but I was pretty sure that it was a new cam, not a re-ground!!! The rocker arm adjustment screws being out all the way, can't be good!! First off it would change the angle that they hit the pushrods at and could cause them to bend, secondly what happens when stuff wears a little bit??? The machine shop says that they did set the valves at the correct height, and they have always been good to me in the past!!!
The other point is that I asked them about static balancing over dynamic balancing. They said that they have not static balnaced anything in 20 years!! They called it 'Saskatchewan farmer technology from 50 years ago'!!! I had to laugh!!
Anyway, my real concern is the rocker assembly!!

Gary, mine's the same way. I'm told, by folks a lot smarter than me, that so long as the valves are where they're supposed to be, don't worry about it. It's just a lot of little variances (in an engine with relatively large variances) adding up. Nothing to lose sleep over.

Still, even though smart people tell me that, I still wonder how bad my cam looks.

How did the machine shop determine the correct height of the valve stems? I hope it wasn't the way my first machine shop did. (or didn't as it turned out).

Thanks Baxter, but I don't know if that sounds right to me!!
David, apparently they have a book that tells them!!! I would assume that if they say that the set the height to specs, and they knew what kind of head it was as I walked thru the door with it, that they set them correct!! Maybe that is a wrong assumpion!! Do you have the correct height for them??

Section A.20 (page 104) of "The Complete Official MGB" by Robert Bentley gives seat grinding specs. But doesn't exactly say what the height of the stem above the head will be. Your seats may be higher now if the shop put in new valve seats.

Any chance you got the wrong valves (too tall of a stem)? As I recall, the earlier heads had a deeper combustion chamber than the later heads. I don't know if the two heads required different valve stem lengths or not.

At any rate, you can disassembe the head and dress down the valve stems to a height more appropriate for your valve train.

Baxter - just as a rule of thumb - you don't want all your engineering slop being taken up in one spot. If your rockers are cocked over, they may wear on the bushings differently.

Farmer! I'm a rancher! Farmers work too hard.

He said 'Saskatchewan Farmer', nothing to do with Oregon ex-hippies turned rancher!!! :o)

Oh, ok.

Now yah feel better, right??? :o)

"ex-hippie", that would imply that Chris is no longer a hippie, why would he go to the Eugene Country Fair then? Still a bit hippie I think.

didn't you say he still has Grateful Dead stickers on his truck?

Yup, He does and his kid has them on his Firebird and Jane has them on her Tercel!!! :o), Anybody have a clue about my problem????????

Sorry Gary. (And my new truck has no stickers. I'll have to fix that.)
You have another engine. Does it have the rocker assembly that you could commpare with? That was one of the thing I wanted to do when you were here, but time flew.

hey Chris, I have an original handbill from a 1966 Dead concert at the Fillmore framed on the wall

That's worth some money! Years back, Ken KEsey was looking for those to do reprints. Jane has a stack of the miniatures that you got when attending, mostly from The Family Dog.

Yes it does compare with other 'B racks chris!! On the pedistals, the short side is 1 and 3/4" high!! I have checked it against 3 others and one had it's adjustment all the way out also! I am confused!!!

Is your spare block going to clean up, or do you need one?

and do you want him to ship it straight to Tom B? with your luck I'd think about it

NOPE!!!! I would love to, but I never give up!!! I will beat this SOB!!!!!

By the way, that Saskatchewan Farmer's static balanced engine is still running. Just needed another round of baler twine to fix the head gasket.
We used to be able to fix everything with baler twine ... then they invented duct tape. Be careful Gary ... half of Saskatchewan moved to BC and they all know the secrets of baler twine technology.

I know Mike!! That was bad!! Sorry!! :o)

At the risk of sounding stupid - you do have the correct lifter/pushrod combination don't you?

Yes, but I do not think that would make a difference, don't they add up to the same length??? Obviously you can not mix and match or your pushrods and lifters, or you would be an inch and a half high or short! All ideas welcome!!!

Gary - have you measured your valve stem lengths and compared the length to an old set?

There are 2 different push rods & tappets for our engines; 1 for up to 'GK', another for 'V'.......

....18V engines had bucket type tappets & longer pushrods than earlier engines!! That's the difference....bet you have older style tappets & 18V pushrods mated to older head!!

...&, do you have shims under your center pedestials?

Okay Tony, but isn't the overall length the same????

Gary - one more time -
Have you measured the length of your valves and compared that length to an old set?
Just looking at some old stuff laying around my shop, some are different lengths as measured from the top of the valve head to the tip of the stem.
While you are measuring - how deep is the valve seat in the head?

Sorry for not responding David!! The head is back at the machine shop to check those exact things!!! Is there a spec for how high it is supposed to be on top of the head???? I do appreciate all the help!! Now i am very curious about the combined lifter and pushrod height on both setups!! Anybody have a couple of each lying around?????

NO, GARY, "LONGER" MEANS ONE SET OF PUSH RODS IS A DIFFERENT LENGTH THAN THE OTHER!....the longer push rods with their bucket tappets are about the same length as the shorter push rods with their tappets but I don't know if they're the same....I do know the 2 tappets fit the push rod differently to get their total length & mixing them will cause a longer combined length!

...David is asking a legitimate question that you're dodging....just go out to your garage, get one of your tappets & pushrods & measure the entire length with the push rod in the tappet, then measure just the push rod itself....then tell us if you have old style or new bucket-style tappets....& give us all your dimensions!

....we can't figure out where your problem is until you tell us what you've got inside that engine....bet David has a couple different push rods he can compare yours to (I know I do!)...bet he also has both types of tappets & can interchange to find the same dimensions as you (I know I do)....

...I'm gonna bet that engine has components from various 1800 engines & you've got one style internal part fighting against the other....were it me, I'd chunk the entire thing & start anew with a virgin long block!

Damn Tony!!! Do you think I am a total idiot??? Of course the pushrods are longer, they fit into a bucket, the other ones fit on top. If you used the wrong pushrod/ lifter combination, you would not even be in the ballpark!!Did I not say 'combined length'?? If not, that is what I meant!! Anyway, I am not dodging anything!!!!! I will leave that for somebody else!! They are the new style (bucket) lifters, pushrods and an older style head!!
Anyway, I e-mailed Moss Tech and they said that either combination could be used with any head, but I am still not sure if they are exact or just close!! If the newer combination is 1/16th of an inch shorter, then my question is answered!! If you do have both combinations sitting there, could you please stand them side by side and see if there is any total combined height difference?? Thanks!!


It would appear that the rocker ratio could be wrong. IE Pedestals too high,
push rods too short. If the rockers have been reconditioned, maybe too much
metal was taken from the face of them. Cam stock diam too small. collapsed
cam followers. These are just a few things to check.......Good luck

Push rods are different lengths as are cam followers.. If you use the
correct combination
You can use any combination you like as long as the rocker ratio is
maintained and the lifters are compatible to the Cam

Those are the replies from Harry at Moss!!

I believe (correct me, David, if I'm wrong) that the 18V pushrods were made longer so that when they went inside the newer bucket-style tappets they'd be the same length as the older push rods & tappet combination....therefore, if you combined 18V push rods with older tappets your combined length would be longer than required....longer enough to cause problems? I don't know...I've never combined them in an engine! However, I'd guess that all they'd do is affect the freeplay of the adjustment screws for the rocker arms themselves....isn't that your case, Gary?

Why would anybody mill a rocker assembly pedestal? For what ungodly reason would somebody recondition a rocker pedestal by shaving it? Did that same person also recondition the deck on which the rocker pedestal sits? Stands to reason that if they reconditioned the pedestal, they'd also recondition the deck onto which it sits.....&, if they did, they wasted a head & rocker assembly

Again, Gary, did you have shims under your center pedestals? If one combines a later hear & an early pedestal assembly using the #4 pedestal from the later head for proper oil flow, does one have to use the shims under the 2 center pedestals of the older assembly? I don't know...however, I don't use them though those shims were used in all engines from 18GB on!

No, Gary, I don't think you're a total idiot! I'm as perplexed as you about some of the things that have happened to this engine...I've built my share of MG engines over the years and am not ashamed to admit that I've built a couple of losers by doing things I later learned were dumb (at the time, I thought what I was doing was okay because I was in the learning curve)....we may be in one of those learning cycles...I also know I've tossed a couple of engines & started from scratch after I screwed up their predecessors...I guess, Gary, we're all feeling your frustration & are getting frustrated ourselves as additional problems crop up with that engine & we're trying to learn from across the continent....

Now, for my final question: Did a machine shop assemble the complete engine or just do the machine work for your assembly? &, do you have a bill of work to see exactly what they did? If you're like me, you probably had them do your machine work & you assembled...&, if you're like me, you don't have their bil of work....so, moot point..question is: did you specify what you wanted done or did they do their "normal thing"....I'm not accustomed to engines other than the MG so I don't know what the "normal thing" is for most engines....that's why I take my MG engines to only 1 machine shop - one with a proven history of working on them....

Okay!! Maybe we are getting somewhere!! My point is that you absolutely can not mix and match the lifers and pushrods!! There would be a difference of approximately an inch and a half!!! When I originally got this engine, it was a mismatch of everything!!
I had the engine bored, line bored, crank turned, new cam bearings installed and the rods reconditioned, and the pistons installed (I had never seen pistons that did not need to be pressed on to the rod) and balanced. On the head, I had new bronze guides , new valves and seats and new springs! I bought a new performance cam and lifters and pushrods to match!!!
The machine shop let me down big time!!! Fist off they assembled the rocker assembly wrong and they did not replace all the guides!! Secondly, they obviously missed a twisted connecting rod!!!!

Now here are some possibilities!

(1) Is there a difference in the combined height of the two lifter pushrod combinations??? That is the most important to answer right now!!

(2) Is there a difference in the height of the pedistals on a newer engine, and how do I tell if I have that????

(3) The head may have been planed a couple of time and the block decked, if that is the case, what is wrong with planing a pedistal!! (nobody has done that yet, that was a posssibility of the problem from Moss)

(4) It is possible that the valves are not into the head far enough, but where do I get the specs for how hight they are supposed to be above the head??

(5) I think that suggestion #1 has to be sorted out before we can go any further!!

Yes, I did assemble the engine myself! It is a little different than any other engine that I have done, but I am sure that I didn't screw anything up!! What gets confusing is all the possibilities of pieces, what can be used with what and if there are side effects!!

Gary...without being in my garage where my parts are, I can't answer some of your questions....maybe David is still at home & can....however, I think I can answer #3:

When one plans a head & block, there's still room for the piston to do its thing by going up into the compression chamber a bit more than originally (actually, planing a head & block adds power to engine by increasing compression)...but, when one plans the bottom of a rocker pedestal & the head deck onto which it sits, one shortens the length in which the push rod has to operate...that affects valve adjustment because the length of the pushrod/tappet assembly stays the same. though the pedestal has gotten shorter.....so the increase in length due to a decrease in pedestal height causes the pushrod/tappet to "push down on the valve"....to not do that, one has to run the the adjustment screws farther on their threads so valve lash is maintained....kinda like what you've got!

...&, with that, I'm out of my league & sneaking into Tom B's or JDW's league ( a place where I'm not worthy to enter! Not worthy! Not Worthy!)

Now, for #2...pedestal assemblies from any head can be interchanged amongst all heads (well, maybe with exception of real early 3-main heads) if one remembers to replace the #4 pedestal where necessary...they work off the combined length of the push rod/tappet assembly & the length of the valves (&, I believe David's correct that some valves were a bit longer than others - I know the notch at the top in some was different than others)...so long as the proper push rod/tappet assembly is maintained, the rocker assembly is happy....combine the wrong tappet to the wrong pushrod & you have problems...

...Hey, Tom B: was it you who once chided me about the shelf life of a rebuilt MG engine (not on this BBS but standing in your shop when I pontificated about building an engine & putting on shelf in case I needed it someday)?

No. If you shave the head or the pedestal, that would lower the rocker assembly, meaning you would have to back out the adjusting screws, which is the opposite of what Gary has.
There is too much metal somewhere.

chris..I agree it would lower the pedestal & cause them all to be backed out...

"...all the adjustment screws are out all the way"

guess I read that line differently than you....so much for understanding what's written...

...oh, another thing that could occur with shortened pedestal is a bent push rod

O.K. I have read this thread about 5 times and it seems to me there are only four possible answers:

1 - The pushrod/lifter combination is too short. I know the long and short pushrods are VERY different so that would not cause this problem - However, does he have some strange pushrods (A series?) that look similar but are slightly different in length?

2 - The valve stems are too short? Or wrong valves?

3 - There is a LOT of wear in the rockers (seems unlikely).

4 - He has a "bitsa" rocker shaft assembly - maybe wrong arms on correct pedestal (again, A Series parts?).

As noted earlier, machining head/block/pedestals would have the opposite effect - and removing enough material to move the adjustment this much would mean a VERY high comp!

I would think that if you decked the block, and shaved the head you would have to add shims under the pedestals, to maintain the proper valve travel.
Just my thoughts.

First off, I would like to move this thread up to the top!!
I think it is a real weird problem, but not unusual! As I say, I have examined a lot of rocker assemblies in the past week and about 30% are screwed out all the way!! Like Baxter said, his is like that! Now Tony, if you shave the head, shave the block and use a a thinner head gasket than it was designed for and buy new valves that are 1/64 of an inch (not knowing if I did or not) shorter than original, you could easily pick up 3/32's of an inch which when compounded, would be 3/16's of an inch!! That would mean that you would have to screw your adjustment screws out an extra 3/16's of an inch, exactly what mine are!! If you shave the pedistals you will not change a thing!! The ratio will still be the same!! I do not believe that that would be a 'DFPO' fix!! It would bring it back to where it started! Now the main question that I see at this point is that if there is 1/16 of an inch difference between the two different combinations!! If there is, that is the answer!! If not, then we need to continue!! Oh!! The pedestal is definitely an MGB pedestal!! Were the newer valvve springs mounted different on the head?? Does anybody know how high the top of the valve is supposed to be above the bottom of the head????? That could be the problem, I just don't know!!!!
I hope you guys realize that I am seriously looking for the answer!! I have nothing to hide!! Tony did indicate that he thought I was dodging a couple of questions!! Trust me!! I am not!!
The other question that I have is if it is a reground cam, do the add on metal before they re-profile??? I am sure they do, but I just don't know!! Anyway guys, keep at it and we will beat this thing!!!

"Now Tony, if you shave the head, shave the block and use a a thinner head gasket than it was designed for and buy new valves that are 1/64 of an inch (not knowing if I did or not) shorter than original, you could easily pick up 3/32's of an inch which when compounded, would be 3/16's of an inch!! That would mean that you would have to screw your adjustment screws out an extra 3/16's of an inch, exactly what mine are!!" Absolutely true but not your original problem!...."on my rocker arm all the adjustment screws are out all the way"....bunch of 'if's', Gary....oh, why would you use a thinner head gasket?

"If you shave the pedistals you will not change a thing!!" Untrue Shaving the pedestals drops them closer to the top of the head through which the rocker arms go...that means the adjusting screws will have to be adjusted out even more to make up for the amount that was shaved off the pedestals (&, shaving the flat of the head on which the pedestal sits lowers the pedestals even more).....plus, if you used a thinner head gasket, that would be even more material taken out of the space between the bottom end of the push rod and the rocker assembly...

...I didn't mean you were literally dodging us because you didn't want to answer the questions...but David has been asking about valve sizes all along & I've been wondering about your push rod/tappet combination all along also...I know I'm real interested in this one as I've got a '63 3-main engine to complete that's back from the machine shop waiting for me to stuff it together...&, I shaved the head & block just lightly to ensure they're flat, bored for tad bigger pistons, dynamic balanced every moving part, new cam, head redone to include all new seats, new valves, different springs, etc....&, I don't want to run upon this problem...&, I believe David has an engine torn apart right now also

OKAY!!!! I think I just saw the light!!! I was wrong!! Here we are, the tappet adjustment is just about coming out down thru the top! That means that I am too short with the lifter train, cam or valves are not in far enough!! I am correct in that it does compound, but where I was wrong is that shaving the head would put it the other way!! It would be backed out thru the bottom, right????? Tell me if I am wrong, (I feel like my brain is in a twisted position right now!!) Assume that I am correct now, then the only problem could be too thin of a cam (I really doubt it!!) the new combination of lifter and pushrod is slightly longer (not shorter like I thought) or what else????? Shaving the pedestals would help, but I want to know why I have this problem!!!! Thanks for your patience Tony!!

I was backwards!! Not unusual for a Canuck!! :o)