engine assembly problem

[badsix]

back in the early days few shops down southern CA. were cutting old 36 and 40 hp VW cases for the late insert cam bearings. Jack, I'm not positive but I think your old friends at Competition engineering were one of the ones that did this. i wonder why this couldn't be done. seems like it would be much easer than narrowing the case. as said just wondering.
Jay D.

[Jack Staggs]

Well, we're not quite on the same page here. Cutting of a worn case can not be counted on to achieve STD align bore for main bearings. If the case was previously bored for oversize bearings, the best that can be hoped for is to retrieve that same size, unless welding of the main saddles is done. I have had this done on a number matching SC with a .020 align bore that was worn over spec. It has been suggested that align bore bearings can be had for $550+ on eBay. Standard bore bearing can be had for much less, offsetting the cost of case retrieval , not to mention allowing for further machine work in the future, if cam bore is still ok.
OK, back to cam bearings. Another suggestion was to machine the case for cam bearings. I wish it were so, and the link given for the 111 198 541 looks wonderful. Early 40hp cases are easily modified to accept these bearings. In fact .010 os bearings can be had, part # 111 198 542. These can not be made to fit 616 or 36hpVW, as the inner diameter is 1mm larger , and would require a custom camshaft with larger bearing journals to fit the VW shells, not to menion modifying the oil passages and thrust. A VW cam to fit these bearings is far too long, with lobes in the wrong locations. I'm sorry, but i think Duane got it wrong. I'll put my money where my mouth is. I will give $200 to the first person that sends me a 616 case, modified for VW cam bearings, a stock 356/912 cam and stock VW bearings that all fit and work together to me for inspection, and I will pay shipping and insurance both directions.
As an addendum, two piece 356/VW cases can be narrowed as well, to retrieve cam bore. The side with the dist gear can only be cut a small amount. The other side, much more.
My experience is based on 49 years of working on VW/ 356, hundreds of engines rebuilds. Others experience may vary.
Jay D, as you said in a previous post, how can you set the valve adjustment on an unassembled engine? Wow.

[JTR70]

Here's a '65 case we have where the last owner attempted to have material added.

The molt looks very scaly and not well formed so after machining I doubt this will make a good contact surface for the cam. I think closing up the case as Jack suggests would have been a better option than what was done here. Thanks for sharing your technical knowledge you guys! Justin

[Impi]

Here in South Africa where even type 1 beetle casings are very scarce and replacements are not exactly cheap it is a common practice to skim worn casings in order to reuse them. Even the distributor side is skimmed and then an amount taken of the brass gear to compensate done well this reclaims many otherwise worthless casings.
Armand

[Carrera_The_Kid]

My experience is based on 49 years of working on VW/ 356, hundreds of engines rebuilds. Others experience may vary.

My experience, having been mentored by Larry Markham for the last 15 years, is to listen carefully when guys like him and Jack talk. If you decide not to follow up on their advice you better be damm sure of your approach. Likely you are on your way to a very $$ mistake

[badsix]

Jack, sorry I sometimes have trouble putting words into writing i guess. anyway I wanted to check my piston to valve clearance. so after getting my pistons back from Competition Engineering with the domes cut to 22* I put my case half on the engine stand I put the crank in with one rod attached, i'm going to do the other 3 also. so with the crank laying in the case half I give it a little spin it turns free but maybe not as free as it should. then the cam goes in I give the crank another spin and its binding in the gears. that's when I came here for help, I couldn't understand what could be wrong. so as a suggestion I installed the old cam gear the binding was just as bad if not worse. I was back here for more help, in the meantime I discovered that the bearing next to the timing gears was not fully seated on the pin. after I cured that everything was good, it spins free now. with the plastigauge I just wanted to check the center main bearing and cam bearings for now, and I know you can't use it on the full bearings. I was just playing with you when I said I couldn't figure out how to make it work with the full bearings. so now i'm ready to assemble the other case half so I can take my valve to piston reading and cc the dome of the piston. i'm maybe doing this a little awkward but I don't have the years of knowledge that you have. thats why I come here to ask, so I can learn something from you.

thanks Jay D.

[badsix]

I have built several engines and have never had a failure. but I probably know just enough to get in trouble with this Porsche engine, they are a little different. here's an engine I built for my street rod, I built everthing but the bore and deck job. its probably 20 years old and still runs perfect. I rebearinged the bottom end a few years ago just to be safe.

[S.J.Szabo]

Mr.Staggs:

A couple questions, if I may:

If one is viewing the 356/VW engine from the rear, putting the case-split line @ 0deg or the 12/6 o'clock axis, is it the case that main bearing wear ovality will be seen on an axis that runs thru (approx) 2/8 o'clock?

In the case of the cam bores, is it the case that wear ovality would be found to lie (approx) on the 9/3 o'clock axis?

Thanks.

[Jack Staggs]

Jay D, thank you for your explanation of what you are trying to do. These engines can be very trickey to set up. My comment of it's simple was a joke. I suggest that you go back to my original post to review how to set up the short block, IE, bolt the case halves together with the crank in place. Then cam only. Many are surprised at how much clearences can change under torque. Once all is free turning, fit the cam and crank together in the cases. If binding occurs then, the cam gear size MAY be at fault. We can address these issues later, if need be.

[badsix]

thanks Jack and i I did as you said, I went back and installed the crank first. I only pastigauged the center main at about .002. then I pulled the crank and did the cam its also at .002. i then checked for valve to piston clearance that came out to be .006. that's with no cylinder base gasket. so the .006 should be ok shouldn't it ?
no problem about the comment that its easy, i'll get you back for that one for sure. but it is fairly easy until you run into a situation like i did with the bearing not being seated all the way. i just couldn't figure out what was wrong, as i did everything right. so after thinking about it and rechecking everything i did i was able to find the problem.
thanks Jay D.

[Jack Staggs]

Mr.Staggs:

A couple questions, if I may:

If one is viewing the 356/VW engine from the rear, putting the case-split line @ 0deg or the 12/6 o'clock axis, is it the case that main bearing wear ovality will be seen on an axis that runs thru (approx) 2/8 o'clock?

In the case of the cam bores, is it the case that wear ovality would be found to lie (approx) on the 9/3 o'clock axis?

Thanks.

Interesting questions. Since I send every case out to be checked, I really don't know for sure, but I have a few thoughts about it. Because the mains are installed with crush, and the cases are a high grade aluminum alloy, I don't think that ovality is much of an issue. Wear seems to be pretty even all the way around, by visual inspection and laying a straight edge in the bore on opened cases. This is only a rudimentary test, as true measurements can only be taken with the halves assembled and torques correctly. BTW, the locating pins in the main saddles are there for that purpose only, not to keep the bearings from rotating during use. Wear in the bores is due to multiple issues though. Heating and cooling cycles can allow microscopic movement between the bearings and bores. Not really enough to worry about though. Whipping of the crankshaft, and the associated pounding of the bearings (particularly at higher rpm's) is more problematic on our little 3 main bearing engines. The nose bearing doesn't really count. Not much we can do there... careful balancing and counterweighted cranks do help. Later cases incorporated anti shuffle pins on the center main to reduce movement in that weak area, a major problem on hot rod VW motors of that era. Early engines used copper washers under the 6 acorn nuts to seal the cases. Over time, they can collapse, leading to lessened torque of this critical hardware, allowing the bearings to move around in the bore. Excessive end play of the crank can cause significant shifting of the #1 main, resulting in wear of the thin thrust flanges. Another major problem with the #1 main, is out of balance flywheel/clutch assembly, usually due to improper pressure plate replacement. Every diaphragm type pressure plate MUST be pinned in to place and marked to assure exact locating, and every pressure plate MUST be balanced as a unit. If an engine is "buzzy" between 2800 and 3500 rpm, the unit is probably out of balance, beating the hell out of the #1. Most folks don't notice until the crank breaks there. Of course cranks can break anywhere, but failure in that area is more common, at least in my experience.
OK, back to ovality, Mr Szabo. My guess is that question was asked due to concerns of the timing gears trying to separate the cam from the crank. On 50mm cranks, a full circle main bearing was used in the #3 location, unlike the split shells on 55mm cranks. The oil passages on the split shell bearings are offset to the locating pin, not equidistant. Fitting of this bearing has an optimum position, at lest according to Harry Pellow. He suggests fitting the bearing in the case with the passage nearest the top of the cases to be in the 11 o'clock location, allowing pressurized oil to be swept to the top part of the bearing to partially negate the forces of the timing gears (and perhaps ovality there?). He does not say so in his books, but I tend to agree with him. I seriously doubt that the oil pressure can overcome the forces of the valve train, but if it's even a little bit better, I'll go with it.
I regards to cam bore, I use a VW type 4 wrist pin to check those bores. It's just the right size, but too short for checking alignment of the journals. Since collapesed cases is not an issue with 616, unlike VW, it works well. Again, the cases must be assembled as previously said to perform a good test. Find a long aluminum dowel to drive in to the center hole of the piston pin. Not to tight, but tight enough to to eliminate false movement. The pin must be inserted in to the cases far enough on the end with the cam plug to achieve reading where the cam actually rides. The tiniest movement can be acceptable. Experienced hands will be needed to to determine how much you can live with. Cams themselves are another issue. The greatest wear is almost always at the end of the cam by the plug end. ANY ovality there is a reject to me. Some cam grinders will allow Parkerizing to be applied on the journals, and then micro polish it off, resulting in undersized journals. Instant reject. Either of these conditions will result in unstable, varying valve clearances under running conditions.
I hope this diatribe answers your questions.

Jay D, I have no idea how you can determine how much piston to valve clearance you have, or how you are measuring it, before calculating compression ratio, and fitting the valve train. BTW, .006 is insanely close. I worry if its ten times that amount. Any carbon build up at all, valve float, spring bounce, rpm above idle, a valve out of adjustment, missed shift, cold start, bearing clear.......... You seem to think that you know what you are doing. From all of your posts, you don't, IMO. Like the Carrera kid said, you are building a very $$ hand grenade. Good luck to you. Even a blind squirrel finds a nut sometimes.
BTW, I really, really like your blown inline engine. If you could, post some pix of the car in the AG section.

[S.J.Szabo]

[badsix]

jack old buddy, I meant to type .060 for the valve to piston clearance not.006. I know I need to get the compression ratio figured first. but I just got these back from Walt at C/E and wanted to check to see if I had any sufficient clearance at all, be for I started figuring the C/R. if you read one of my previous post I did say I probably know enough to get in trouble with these engines. a SBC or an old GMC inline or older VW I've done several and feel comfortable with them. with the 356 i'm not, that's why i'm asking all these questions. you know Jack I got up this morning and showered and shaved as I was shaving I looked in the mirror and I didn't see moron inscribed on my forehead please don't treat me like one, i'm just asking for help. if you want to be funny that's great I like a good laugh. so back to the .060 do you think i'm in the ball park with that
thanks Jay D.

[badsix]

SJ its an old 50S 270 GMC. here's another one, this my boy with a little of my help built. its a Honda xr80 80 cc with a Porsche smog pump for a blower, good for about 8#. runs but not good, with the belt drive we had to remove the mag and stock ign. so we went to an electronic with a magnetic pickup. the way it is we're not getting the proper advance. its not good for much but he did learn a little and it kept him out of trouble.
Jay D.

[badsix]