Engine Variations

[jws]

I just learned my '68 Beetle has a '66 1300cc, SP in it. I want a 1600cc DP. Can I use the short block I have and just switch the jugs, pistons, etc. and install DP heads? IOW, install a 1600cc kit? I also plan on dual carbs; size TBD.
Regards,
JWS

[The Newf]

Assuming it's an original 1300,it would be poor foundation for that kind of upgrade.I would keep the original 1300 intact & build another engine properly.

[jws]

Thanks much for the response. I think this is good advice. I'll take it. I wanted an 1835cc originally, so would you suggest I start with a 1600cc? I'll freshen the 1300cc and probably sell it later.
Regards,
JWS

[The Newf]

1776/1835/1915 are ALL great non-stroker engines when properly done.

[Marc]

What's the ID code on the engine case (should be stamped just under the generator pedestal)?

The original 1500 case of the `68 would've been an H5 - worst case ever made, lousy alloy. Good only as a doorstop, although you do still see a few that have miraculously survived in stock configuration if they haven't been beat on or overheated. If you've got one of those, be nice to it but don't waste any time/money on it.

A `66 1300 would be an F0; essentially the same as the `67 1500 H0 - these are a better alloy, although after almost 50 years' service they may still have issues. Biggest problem is the small oil passages; although you can build a higher-performance engine based on one (it was all there was to work with back in the day) it's far better to start with a later large-passage/dual-relief case.

1300s have unique SP heads, with smaller intake ports than 15/1600SPs. Valves are 33x30 vs 35.5x32. Useless for performance, but if opened up to accept 1600 cylinders they can be used to make a very nice "driver" motor.

VW didn't start "cross-drilling" their crankshafts for improved rod bearing oiling until 1968. In the middle of the `66 production year the way the flywheel was sealed to the nose of the crank was changed from a gasket to an O-ring; if you have a "12V" 130-tooth flywheel, you either have the late `66 crank or someone modified the 'wheel to fit on the early one (all 130-tooth 'wheels are O-ring style).

1200 and 1300cc engines came with 180mm clutches, while 1500 & 1600cc all got 200mm. The little clutch really isn't adequate for the larger engines. You can get stronger 180mm clutches (like the ones used in 356 Porsches) but the pedal pressure/clutch cable strain is greater. Much better to step up to the 200mm clutch if increasing the performance of a 1300.

For your first performance-engine project, I suggest you look for a rebuildable '71-`74 engine and build it 1775 (1835 at the most, and then only if you use the AA thickwall cylinders). That'll give you the most bang for your buck, allowing you to retain stock-valve heads - some mild intake port work is worthwhile - and stock heater boxes. You could even use the stock non-counterweighted crankshaft provided you set it up to reach peak power by 5000 RPM (Kadrons would be appropriate carbs), although you'll need to have the crank & flywheel 8-dowelled to keep them together.

[jws]

Thanks very much for all of this info. The engine code of my engine is indeed FO, so a 1966 it is. I will attempt to locate an engine as you suggested. My little 1300cc engine runs great as is, so I have some thinking to do. I have just begun my work, so i'll keep everyone up to date on my progress. With info and assistance like i've received so far, my project should proceed readily.
Regards,
JWS

[WooleyNelson]

I'll freshen the 1300cc and probably sell it later.

That is probably your best move....

You might find someone out there restoring a 66 that would like to have a pure stock original 66 engine.

Good luck!

[jws]

I disassembled my engine and found it to have 1600cc(85.5) P&Cs. I do not know if my case is "thrust cut" or if the case has been "cut". I'm not sure how to tell the difference. I'm really not sure which course to take, as I wanted at least a 1776cc engine. All advice is appreciated.
Thanks much,
JWS

[Marc]

1300, 1500, and 1600 all share the same cylinder register diameter. There's no difference between a `66 1300 "F0" case and a `67 1500 "H0" case other than the ID number. 1300 heads had smaller valves (33x30mm vs the 35.3x32 used in later carb'ed engines) and smaller intake ports/manifolds and a smaller cylinder register, so they need to be flycut to accept 15/1600 jugs. If you have the smaller valves, the heads are 1300; if they're 35.5x32, the heads have been changed and essentially it's a `67 1500 that's been taken out to 1600.

1300 heads on a 1600 are restrictive at the top end but boost low-end torque; makes for a very driveable, high-mileage combination (when you get to the red marks on the speedo, you may as well shift). Excellent combination for an around-town daily driver; also makes for a nice Bus engine.
With 15/1600SP heads, there's nuthin' special going on...and that's the maximum I'd build an F0/H0 case for, they're inadequate for a dualport. Just an "OK" engine, will get you around but not worth investing much into building. Sell it or keep it under the bench for a spare.

The F0/H0 cases were good pieces in their day as the basis for a mild, single-port engine, but for any kind of performance motor you should start with a large-passage/dual-relief case. 1970 B6 and early`71 AE being the minimum...later cases with the washboard ribs cast into the panel below the dipstick are a better choice. Those with 10mm head studs will need steel "case-saver" inserts installed to assure longevity, so look for one with 8mm studs (they were inserted from the factory).

1775 is a good choice from a "bang per buck" perspective, a mild one can still use stock-valve heads and stock heater boxes and make ~65-70 honest HP with dual single-bbl carbs - but there's enough torque on tap to shed the flywheel if you don't 8-dowel it, and if you choose a cam that makes power beyond ~4500 RPM or so you'll be needing a stiffer valvetrain...and ~5000 is about the limit without a counterweighted crankshaft - it can easily take twice as much money to make another 20 (durable) HP once you step off that cliff, by that point it's not a great deal more costly to go for even larger displacement...what are your expectations?

[jws]

Thanks much for such good info. I've had no luck, locally, on finding a proper case as you suggest. I'm pretty set on building a 1776cc with dual carbs, ( size tbd). By the way, my crankshaft has at least 1/8" end play. Not sure why. Everything else looks fine.
Any ideas about my excessive crank end play?
Thanks again,
JWS

[Marc]

..my crankshaft has at least 1/8" end play...
JWS

There'll be that much (or more) with the flywheel removed...but if it's that sloppy when together, the most common cause is the #1 main bearing "walking" back & forth in the case. Fitting a bearing with a thicker thrust flange, after machining the thrust surface of the case to match, should clear that up. Bearings are made with 1mm-thicker flanges for this purpose; 2mm-thicker are even available for the larger-diameter linebore sizes.

⅛" = .125", and 2mm is only ~.080", so in cases with extreme wear there's no simple remedy. It's possible for a good machinist to pin brass patch pieces in, but that's not economically viable for such a low-value case.

As noted previously, there was a mid-year change in `66 in the way that the flywheel is sealed to the crank - a late flywheel won't seat fully against an early crank, which would result in excessive endplay (not to mention oil leakage and a very weak connection between the two). Not likely that this is your problem, but something to be on the lookout for. Another consideration in this area is that the early endplay shims have a ~1mm larger I.D. and if used on a late crank have a tendency to sling around, actually cutting a slice right into the crank...if the shims drop into this groove one can get a false reading when setting the endplay. The thing about excessive endplay is that the worse it gets, the worse it gets - just a little too much allows the crank/flywheel to start pounding against the thrust bearing, causing it to beat itself into the case, increasing the endplay further. Once the bearing starts to walk in the case, things go downhill fast.

...I've had no luck, locally, on finding a proper case as you suggest. I'm pretty set on building a 1776cc with dual carbs...
JWS

If this case is even salvageable it's almost certain to need quite a bit of machine work just to be buildable as a stocker, let alone as a 1775 - you should keep looking for a later core engine to start with.

[jws]

I've had no luck locating a good (quality) 1600 engine, so I'm seriously considering a turn key 1776 replacement engine from either GEM or Strictly Foreign. Both have good reviews and are closely priced. I'm looking for advice on these companies or other recommendations. I seriously need your help.
Thanks much
Regards,
JWS

[Marc]

I have a low opinion of longblock-mill engines in general since they have to be built to a price point. I have no (recent) personal experience with any so I'm of no help on this question...hopefully others can offer recommendations.

[jws]

Hey. I've lucked out. I've purchased a 1971, 1600DP, dual relief, AS41case. I've disassembled it and checked all bearing, rod and thrust clearances and found all to be well within specs. After cleaning the case, I can find no cracks or defects, except for slight erosion on the oil drain plate mating surfaces. Again, all internal specs are good. The case has not been cut. With such good numbers, do I need an align bore? I don't think so, but I'm looking for help. My plans include a stroker kit to about 1800cc.
Thanks much for any advice,
JWS

[Marc]

Hey. I've lucked out. I've purchased a 1971, 1600DP, dual relief, AS41case...all internal specs are good. The case has not been cut...

Definitely a rarity for a 45-year-old engine...must've been sitting for a long long time (most cases I've encountered with more than ~80,000 miles on them have needed align-boring). Ordinarily I'd recommend pulling the head studs and having steel thread inserts installed, but this one may be good to go without that (assuming you won't be adding a turbo to it).