Inside the case: building for reliability

If your going to have any work done on the case get it sorted for full flow. External oil cooler and filter. I've got a 1776cc and put the externall cooler above the gear box on a 1964 bug but i would have thought being a bus you would have a few more places to put it. This way there is more oil in the system plus extra cooling. if you do full flow go fore a higher pressure pump. New camshaft = New followers (there cheep enough)

later,

John

Remember, teh CR can also be TOO low. Gene Berg preaches for ultra low CR, below 7:1 even. Personally, I strongly feel that this makes teh engine harder to tune, and gives poor power (duhh) and poor mileage. The gasoline isn't burned efficiently enough. Bus or bug, doesn't matter. Stock CR is 7.3:1 or thereabouts. (Varies between models). With a stock cam, stay there. There's no benefit in running lower than stock CR. I'm not alone with this statement either.

Don't rely on a visual check. Try lifters in their bores, if they "rock" or not. Some movement is allowed. I guess it takes some experience to know when they are too worn. maybe show them to someone? Someone who isn't ready to sell you a new case? ;)

I have a feeling that people discard cases too easily in the US. I don't mind, it keeps the prices low. (Well, lowER)

It's always a good idea. No need to actually remove a lot of material, just make sure that the surface is straight and clean.

Ok. Case & crank worked on by them, so buy bearings from them too to match the new dimensions. And make sure they tell you what they are.

I don't fully agree. A mild Engle W100 would work well for a bus, you could still use your stock carburator and stock distributor. takes some extra time to get it tuned right but it should be well worth it. If you give me a week or two at max, I will have finished one of these for a friend's bay window bus. (1600dp). I could tell you how well it runs, as opposed to a *bone stock* 1600 which I just finished for another customer (bay window again). He messaged me from the eastern part of the country recently and complimented me on how smooth, cool and great the engine runs.

And I thought it was a total slug. :)

The added lift has virtually no negative side-effects that I know of. It's not a "wild" cam, in the sense that it would cause premature wear or need for maintenance. (W100)

No need for anything fancy. Just new, if the cam is new.

Whatever Rimco sells you. They should know.

I don't really know how they "rebuild" rods. On high performance engines, I wouldn't trust them no matter who made them, if they were in need of any kind of rebuilding. It means they had something wrong with them to begin with. Bent? Overheated? Pulled out of a wreck? Spun bearing or bushing? Do they x-ray or magnaflux them to check for microscopic cracks in the neck area? New is new.

26mm tall gears, aluminum Schadek pump. Normal pump outlet threaded and plugged. Steel cover with outlet.

Don't buy the cheap BugPack swivel foot adjuster screws, the ones with solid shaft that have a ball bearing "captured" in a solid cup. They might work ok in a stock engine, but they snap in higher revving engines with only slightly more spring pressure. I don't want to tell you how I know. And no it was not a geometry issue I overlooked. :) At least get a second, and third opinion from some other people who have used them for a longer period of time.

In fact, anything I say, or anyone else says, should only be regarded as one of many opinions and suggestions that you collect. Ask from a dozen sources and then make your own informed decision based on the answers you get. if there is a clear consensus on something among all who replied, then it most likely is true.

I do it on all engines I build, no exceptions. The factory built engines were mass produced, and thus could onlyt be built to certain (very loose) tolerances. When you build a one-off, you can do much much better. For example, the con rod weights must all fall within 8-10 grams of each other (depending on the source quoted). That's sloppy. I can get them within 1g at home with a simple electronic scale. Same with pistons. (they are usually better matched by the manufacturter, especially if they are Mahle).

Dynamic (rotating) balancing of crank and flywheel is a must. First the crank alone, then the flywheel balanced to "zero". Then maybe double check them together. (Why? if for any reason you need to replace the flywheel in the future, or remove it and put it back together... you can, and as long as the one you put in there is also balanced to zero, you will not have disturbed the overall balance at all). You don't even need to know which position of the 4 possible the darned lump was installed in.

Pressure plates today SHOULD be balanced to zero by their manufacturer. Doesn't hurt to have it done together with the other parts however.

The cheaper way is to have the whole crank-fw-pp combo balanced together. Then you just need to be sure their relation to each other never changes when you pull them apart and re-assemble 3 months later. ;)

Heat: good quality oil, clean engine,good engine bay seals, proper tolerances and CR, proper tuning (jets etc.) and the head cooling fin work you have already been informed of. That's the ticket. And abandoning the fantasies of owning a race car (keep your foot out of it)

This is my "scratch of the surface" for ya ;)

There are certain areas where you can go beyone "factory spec" and improve things a little, much like the con rod weight matching. Some extra cleaning of casting flash here and there, chipping or grinding away sharp edges or burrs, flash from inside the case... tiny details I can't even remember to list here in one sitting.

Jan

Full flow is a good idea but I would question the need for an external oil cooler. The doghouse setup works great and was designed to meet the demands of a stock performing engine, which I know its a 1776 but I wonder if it creates any more demand on the cooling system than a 1600. Besides, has anyone ever proven that those external coolers actually perform better than a stock system??

--Dan E

...check out the web 119 cam. It works very well with ICT's or Kadrons....is a good broad range low rev cam. It was the cam reccomended to me by webcam when I built a 1776 for a 67 bus. Engine pulled great...and ran nice and cool. 7.5 to 1 compression. Use Web-cams lifters as well to avoid compatibility issues. ...RIMCO can provide you with rebuilt and balanced rods. You will need to wait until you get your crank ground to buy your bearings. ;-) Balancing is ALWAYS a wise move...the engine will run smoother get better mileage and last longer. Always blance all parts if you can afford it, the dividends rewaped will worth the money sown..

...Gareth

11 grams off times 6000 rpm is quite a bit of pounding on the bearings ;)

Thanks for scratching the surface for me, Jan -- lotta good tips there.

One thing about the cams, though. As I understand it, the inner of the two circumferential grooves on the follower is drilled to provide oil to the hole on the end of the pushrod, and from there, eventually to the rockers, etc. This rocker oiling groove lines up with the oil gallery port in the bore when the cam is in the lift position.

Oil gets to the oil gallery port of each bore around the bodies of the other followers upstream because each follower has that second groove cut around its body -- the oil transfer groove -- which lines up with the oil gallery port when the followers are sitting on the heel of the cam's lobes, i.e., the valves are closed.

It's clear from looking inside the case that if anything were to block this gallery, the other bores downstream would not receive pressurized oil and there would be little if any forced into the push-rods when their respective rocker oiling grooves lined up with their bores' oil gallery ports.

The distance between the oil transfer groove and the rocker oiling groove is about .310 (I'll work in inches here because that's what my calipers use). The lift of the stock cam is about that, too. This is intentional I reckon, as it assures that when the follower is lifted the rocker oiling groove lines up with the oil gallery port, and when the follower is not lifted, the oil transfer groove is lined up with the oil gallery port.

When a cam with more lift is installed, they can't make the lobes higher: the followers can't be pushed any higher or they would bump into the case (near as I can tell)*. So rather than make a higher lobe, the heel is ground closer to the center of the cam -- a smaller root diameter. This means that in the non-lift position, the follower now rides so far inward that the oil transfer groove is no longer aligned with the oil gallery port, and now the oil can't get around the follower to the other bores downstream.

The W-100 has 0.383 lift at the cam. This is about .100 more than the stock cam (actually 0.098 more than the stock intake, and 0.106 more than the stock exhaust). So if the follower spends 90% of its time on the heel of the cam, and during that time the oil transfer groove is too far in that it no longer lines up with the oil gallery ports -- how can oil get around the follower to the other bores downstream?

The only workaround I can see (from my tiny experience) is to use followers that have been modified to provide an oil transfer groove closer to the cam so that oil can get around them when that follower's valve is closed. Otherwise it seems like we are defeating an important bit of the engine's lubricating scheme.

*If I am wrong, and the lobes on aftermarket cams are in fact higher, would that not mean that in the lift position, the follower would be shoved too far outboard for the rocker oiling groove to line up with the oil gallery port? Either way you cut it, ONE of the two grooves is not going to line up with the port and lubrication to the heads is gonna suffer.

That is why there is an "old" but not to well known trick around, simply to machine a relief cut between the two grooves, there are more involved and trick procediures also...

Mr.Hoover?

J.

A relief cut between the two grooves makes great sense when the grooves line up with the oil galley port, as it would make sure that pressurized oil is presented to the rocker oiling groove and thus to the heads. Connecting the two grooves together doesn't seem like it will help when the one or both grooves are not lined up with the oil gallery port. If the oil transfer groove is not lined up with the oil galley port when the follower is on the heel of the cam, no oil will make it past that follower to the next bore. That's why it seems that you'd need to cut one or two new grooves around the follower to get things lined up.

I may be missing something still.

Yeah thanks. When I wrote "keep the CR nice and low," I meant I plan to make it handle low-octane California gas -- something like 7.5.

So far so good. Now I'll snip some of your text to jump to the juicy part :)

On a performance cam, there's room for extra lift at the lobe. The top of the lobe does in fact come further out than the stock cam lobe, pushing the lifter(Follower as it is also called) deeper into the case bore. With very high lift cams, you need to replace the stock lifters with ones that have a shallower base, to avoid bottoming the lifter out against the case.

Usually with very mild cams you are able to choose the "standard base circle cam) option. The W100 (and W110) should both be made with a standard size base circle, as far as I know. DOn't know if all of their clones are available like that. But they aren't that "wild", I can't see why they would need to be made with reduced base. Well, to be sure you should check yours against a stock cam. Or measure it and ask someone (me, for example) for stock cam base circle size. In fact... let me go measure mine right now.... there. stock cam base circle is around 31mm ( 1.2 inches according to an online converter ). I don't have a W100 at hand, out of the engine, but a W110 clone I had was with a 29mm base circle. That's roughly a 1mm difference in the lifter movement on one side of the engine.

Your concern is valid though. When the lifter starts to move in (considerably) longer strokes, the oil grooves and holes spend less time lined up per revolution than before. Bob Hoover has posted instructions for modifications in his "HVX" mods article some time ago. You cut three extra grooves into the lifter, to connect the two oil grooves. This way, when the transfer groove lines up with the case oil hole, and gets pressurized, the oil will also find it's way to the rocker oiling hole in the other groove.

Measure your base circle and go from there. If it's stock size, you won't need these extra grooves. My guess is that the W100 is so mild that it will have very marginal effect here. Don't worry about it. It won't become a critical factor until you start building race engines... :)

Jan

The lifter (and it's oil grooves) will still "fly past" the oil hole in the bore during it's movement. If the two stock grooves were connected as PJ and I described, then you have TWO grooves flying past the oil hole in the bore, during one stroke of the lifter, BOTH providing oil for the rockers. Instead of just one groove.

Jan

Aftermarket cams should allways be used with their matching lifters. That is not only so that the friction surfaces are of compatible metallurgy, but also so that the bottom (closer to the cam) oil grooves on the lifters line up correctlly (if the manufacturer has done something about it).

Anyway, the theory of operation of the stock system is this: Each rocker / rocker shaft bearing surface needs oil pressure only when the valve is being pushed, especially while opening and on higher lifts where the spring tension is higher. When the valve is closed, there is no need for oil pressure on the rocker. This is exactlly what the stock system does.

Oil pressure is first suplied to the inlet valve followers. Each inlet valve follower may block the oil pressure only to the exhaust valve follower of the same cylinder.

When the inlet valve begins to open, oil pressure to the exhaust valve is blocked, but oil pressure is not needed in the exhaust valve because it is allmost closed at that point. When the inlet valve is allmost opened, the top groove on the lifter will line up with the oiling hole directing the oil pressure to the inlet rocker arm. The line up point is better to be a bit lower than at full lift, cause it will line up twice (but it remains allmost lined up between the two points continuing to pass the oil pressure to the rocker), once while the valve is allmost fully opened and once while just begining to close.

Then the inlet valve closes, directing oil pressure to the exhaust valve follower. The exhaust valve is closed at this moment, so the exhaust follower blocks oil pressure to it's rocker. After the compression and expansion stroke, the exhaust valve begins to open, but the inlet valve stays closed. Now the exhaust valve gets oil pressure the same way as the inlet valve, without being interrupted by the inlet valve, which will start to open when the exhaust valve is allmost closed.

If you understand this, you will see that only the bottom groove on the inlet valve followers need to allign with the oiling holes in the lifter bores. If you want to improve the stock oil system you have to enlarge this grove, so that there is not much loss of oil pressure from the inlet valve follower to the exhaust valve follower. Also enlarging the top groove, provides oil pressure for a longer amount of time to the rocker arm.

Another weak point of the stock system is where the oil pressure passes from the left side of the case to the right side (behind the center cam bearing). You can enlarge the groove on the case behind this bearing to reduce oil pressure losses there.

Installing a higher lift cam will not affect the operation of the stock system if the bottom groove of the inlet valve followers is alligned with the oiling holes. The top groove position can still be in the stock position. The only difference will be that the line up will be at -say- 75% lift instead of -say- 90% lift of the stock cam. Thats why high performance aftermarket cam followers have larger grooves.

Another improvement to the stock system is to use rocker shafts that have a groove arround the rocker arm friction surface. This is to direct oil pressure to the lower side of the rocker arm (towards the cam) where the actual friction area is.

Connecting the top and bottom grooves of the lifter together, will result in pushing oil to the rocker arms 100% of the time, even when the valves are closed and this is not needed. This results in lost oil pressure on old worn engines or on an overheated engine when oil pressure is mostlly needed. Also, this results in much more oil on the top end of the engine (on the heads) and unless you install valve guide seals (modified guides need to be installed) you will be burning oil from the valve guides. You will then need a deep sump even in a very mild engine to ensure that there is allways oil in the case, cause the rate that oil drains back to the sump remains the same but the rate that oil goes to the heads is increased, drying up the oil supply on high revs. The benefit of this modification is that you use oil to drain heat from the heads, so you will also need improved oil cooling.

Bill, '67 Bug.

Not so. If you connect the two, all you do is provide the pushrod oil hole to receive oil TWICE during one pass. (In stock form, the oil hole in the case and the bottom groove of the lifter are lined up only once). This still is less than 50% of the time.

This is how they work: Valve fully open, lifter almost fully into it's bore: oil hole in case and bottom oil groove in the lifter are lined up. oil gets to the pushrod.

Valve starts to close, oil hole in case no longer lined up with the lifter groove. No oil to the push rod.

Valve closes even further. Second oil groove now lines up with the oil hole. If you didn't cut any extra grooves, this oil pressure only lubricates the lifter bore itself plus allows oil to pass to the lifter next to it. (Which is at a different phase in it's travel compared to the one that's now "sending" oil to it)

The valve (and lifter, duhh) next to it aren't. They'd be happy to use whatever spare oil pressure is available. The lifter oil galleries are connected to each other on both sides of the engine. Only the path for oil flow goes through the groove on the lifter itself, not in a separate passage. When the holes aren't lined up.. neither the pushrods or the neighbor lifters get oil. It's the two furthest lifters that are starved on each side of the case, the two in the middle are fed directly.

Boy that's gotta be hgard to follow. I lost my thought after re-reading what I just wrote. :)

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Through where? Pushrod ends when they get loose, or through worn lifter bores? Well assuming you started with good lifter bores, the improved lubrication in them would slow down their wear.

I have no answer to the pressure possibly lost through pushrods. I didn't think that far. So let's see.. I'm not sure the oil holes or grooves are lined up when the valve is fully closed. If they are, then oil could escape through loosened up pushrod tube ends. But only if the top groove was lined up.

Depends on cam lift and base circle.

Anyhoo, these mods shoule probably be accompanied by a higher volume oil pump. Basically, the "connecting the oil grooves" trick is only a part of a larger, overall modification of the engine's lubrication system. I don't know how well it all works if no other mods are done.

You too have been reading up on the HVX mods :)

Excuse me if I made any brain farts there, I'm sick and not thinking

100% clear in my fever.

Jan

I can see the "flying past" part, and if each bore had its own oil feed, then this idea would be a peachy way to send more oil out the pushrod. But consider the last bore in the galley line. When its grooves fly past its oil galley port, the other three followers upstream better be flying past also at the same time or it will have no pressure. Even with their grooves connected together, all followers need to have at least one groove lined up with their ports for pressure to reach the pushrod at the end of the line. If one is not lined up, the galley is plugged and downstream bores get nothing.

Who has timing charts? Assume that the four followers on (say) the starboard side of the engine have their grooves connected. Turn the cam. Is there a time when the frontmost follower (#1 exhaust)has its grooves lined up with the oil galley port while the next bore aft (#1 intake) also has its grooves lined up? If yes, then some oil can squirt into #1 intake pushrod. Now consider the next bore aft (#2 intake) -- is there a moment when #1E and #1I are lined up so #2I can get oil? Finally, #2E needs to have all three of the other followers flying past their grooves in order to get any oil at all. Does this happen?

Oooooo mah head hurts

Jan

Correction, in the previous post when I wrote "Bottom" groove I meant "top" groove and vice-versa. Anyway It's complicated to describe in words, I have to make some drawings to explain it.

Bill, '67 Bug.

I'm glad I'm not the only one getting puzzled and confused :D

I'm done now, I can't think anymore. Hopefully Bob will chime in and lay it all out in a clear way.

Jan

I have to make some diagramms describing what I was telling, I will post them soon. It's confusing to put it in words.

Bill, '67 Bug.

Excellent, thanks Bill. A picture is worth a thousand words and so on

Jan