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Thu Aug 20, 2015 9:51 pm

I have been building a fiber fab avenger gt-12 that I pulled out of a field, last on the road in '74. It came with a transferable registration, which is the equivalent of a title for certain older vehicles in NYS. It's for a '62 beetle. The PO gave me a 1300 power plant from a '66 based on its serial number, that spun freely but was in need of complete tear down. This is only relevant so you know that I'm not looking to tow a full bodied beetle around, and that I didn't abandon the bug that once was for the kit... But it has been the spark o get me into the vw subculture. I am looking to build a motor that will get out of its own way (no issues on thru way on ramps) but is fairly budget minded. I'm under the impression that by eliminating the heater boxes and swapping out the stock pistons and cylinders for the largest bolt ons I can use, I'll be where I need to with this motor. My questions are, what sizes can I actually bolt on to this case without machining? I see 88mm sets advertised as bolt ons and I'm going to be angry if something comes to my door that will make my case need machining, because at that point your over the edge and should just go the extra mile for 92s or 94s. So what will really fit? The other question is, if I'm just towing around a fiberglass shell, does a larger set of pistons with stock 69 crank and flowed /ported heads, and the removal of the heater boxes become enough to create a fun to drive/peppy enough to get out of its own way ride? I think the buggy guys will possibly be experienced with this progression? Open to ideas but still trying to do my due diligence about combinations and specs building these motors, and honestly would like to have heat, but willing to sacrifice if it's that much of a performance improvement.

Thu Aug 20, 2015 10:53 pm

Londog,

You want more performance than a 1300, but have a tight budget - got it.

The largest cylinders which will fit in a stock 1300/1500/1600 case is 88mm.

Trouble is, there are two sorts. The 88 slip-ins have VERY thin walls and almost always end up warping and leaking at the heads - the sealing lip there is just too thin.

But these days you can get 88 machine-ins (don't stop reading!!!).

These are thin at the bottom so they slip into the unaltered case, but are stepped so they have nice thick walls and a good sealing lip at the top. You need to flycut the heads (hence machine-in) so they will fit over the larger cylinder tops. 1679cc and a good long life.

The other option is 87s (1641cc). They slip in too (case and heads), but there is no thick walled version so you still run the risk of warping if they get really hot - some folks get a decent run out of them, others get a short life.

BUT - your early 1300 case might not be suitable for other reasons - mostly the use of cylinder studs screwed straight into the case metal - these CAN pull out with larger capacities and older engines, and really would benefit from case savers (threaded collars) in the case, to increase the area of contact in the soft case material. Using a later double letter case (AB, AD, AS etc) are better choices. The best are those double letter engine numbers with either AS21 or AS41 cast into the side of the case - this tells you it's a later "aluminum" case which is much better for rebuilding and re-machining if needed.

With a light weight body, you dont need bags of power for a fun drive - 65hp or so from a 1679cc engine will feel just great, and keep you up with modern traffic just fine.

With that capacity you can still use a stock style carb - H30/31 is the largest which will fit on an sp manifold, or if you change to tp heads and larger flange manifold to suit, you can use the slightly larger 34PICT/3 - the engine will still look stock, and parts availability wont be a problem.

With that older case you might have other problems too - it might have the cam running directly in the case material rather than later practice of using proper cam bearing shells.

Depending on your choice of carb, you'll also need to choose a suitable distributor. The 009 is often chosen with a H30/31 carb as these carbs have a low vacuum signal which can struggle to pull in the vacuum advance component. So you might end up with some acceleration stumbles as the bug engine needs both a shot of advance from the distributor (missing with the 009) and a shot of fuel off-idle from the accel pump to spin it up smoothly.

If you end up using a 34PICT/3 carb (larger tp manifold), it works best with an SVDA distributor - both vacuum and mechanical advance. It does NOT work well with the 009 distributor.

You can't use the original SVSA (vacuum only) distributor unless you have a suitable carb with the correct vacuum signal - that usually means one of the smaller 30 series - 30PICT/1 or 30PICT/2, and the EARLY 30PICT/1s don't have a power jet which is essential for capacities greater than 1300, or the engine will run very lean at higher revs (can you say "might get hot and seize"?) So only the later 30PICT/1s or the 30PICT/2 would do there. Of course these smaller carbs will restrict airflow for a 1679cc engine and reduce your max revs and hp.

All of that assumes you are using the stock exhaust. You'll get a could of extra hp if you change to a header style exhaust and drop the cabin heaters, but that means more re-tuning of the engine due to the change in back pressure. You COULD go with the stock system first and see how if feels on the road, and then try for a couple of extra hp with a fancy exhaust system if you want later - as the budget allows.

So there are a few things for you to think about.

Fri Aug 21, 2015 7:56 am

Pass on the 1300 and get a 1600 single or dual port... Even in stock form it would be enough to get around in. In the future it would be easier to modify with bolt on performance.

Fri Aug 21, 2015 9:53 am

Londog wrote: The PO gave me a 1300 power plant from a '66 based on its serial number, that spun freely but was in need of complete tear down.

The best thing to do would be to evaluate what you have now, and then decide what you really need (or just want).

Re tourque the heads to factory specs and adjust the valves. Then do a compression test.

Measure the crankshaft endplay.

Knowing these things will help when deciding on what to do with this engine.

Wed Aug 26, 2015 8:59 pm

I guess the difficulty is that the expense of building the entire car is so much that cutting cost of certain things like the motor will get me in it faster. I know many minds would say do it once, do it right. But I am a modest guy who wants to drive something I have built in this lifetime. My wife has battled stage three breast cancer and has a high likelyhood of a recurrence in the future, so I face the world differently in that I don't want to spend so long waiting on funds to finish this thing, trying to go over the top on everything like we all would love, but instead to finish it at all so I may drive it and improve it along the way. At no point do I intend to cut corners and be unsafe, please know that also. I'm interested in what will make this thing peppy enough as I said. If there are better suggestions on where the money could be spent to make power, I'd love to hear them. I hear these suggestions and do rationally believe that finding a functional 1600 off Craigslist for a few hundred could be a viable option. But that too will need investing in. Not to mention I still have a '62 transmission and I don't know how much trouble it will be to grind out the bell housing to fit he flywheel in. I've seen it done, but don't know about the dependability of the combination. In the event I do build this motor, I could continue it here as a build thread, and possibly do a separate whole car build thread (even though I can't imagine I'll turn out anything as nice as the yellow one jspbtown built). I appreciate the feedback thus far, but again. How much power is legitimately enough to drive this thing with some confidence? I need to check for the cam bearings yet and look at the serial number again.

Wed Aug 26, 2015 9:11 pm

I have to add, the motor is currently on a stand torn down to the block about to be split. It sat in a garage for the past 30 years. I figured at least bearings and seals were necessary, so a tear down was too. So I could reassemble and do a valve adjustment, but I guess while I have it apart, what's the best way to spend money getting it back together? I guess I fear picking up a 1600 someone pulled to change the rear main seal or had a shot bearing and they wont inform me of that, and trying to just rebuild the carb and drive it, only to have to tear that all the way down too. I don't know, I guess everything is a crap shoot until I've done the work myself right?

Wed Aug 26, 2015 9:46 pm

Here's a bit of reading for you:

http://www.aircooled.net/1800cc-vw-engine-no-machine-combo/

While thats not exactly a budget build that John outlined in that tech article the point of it is you can build a bigger motor than a 1679 no-machine motor. I built a 1641 years ago that was pretty damned fast for what it was. I ported/polished the DP heads myself using Bill Fisher's How To Hotrod Your VW book. I had the heads flycut .125" deep and a three angle valve job - I hand lapped them for a nice mirror finish. Compression ration was right around 10.5:1 compression. I had to saw the last fin off the heads to allow the cylinders to seat in the heads. I reworked the crank for max oil flow to the bearings. I installed a Norris hydraulic cam/lifters - added an S&S header and a pair of Kadron 40mm carbs. Fire came from a German Bosch 009 dist. The car was a 64 Deluxe Bug with stock gearing of 4.37. I had over-sized tires on the back - IIRC they were an F70-15" 'wide oval' something or another on stock wheels. The taller tires gave me some great gearing for the freeway. I could easily peg the speedo which went to 90mph! According to a brother in law's speedo in his 66 GTO I was doing 105 flat out when he paced me. Bugs aren't exactly aerodynamic so it was quite the speedster. The front end got real light at anything past 80mph.

I still have that Fisher book - its almost ready to be punched and put in a ring binder - the pages keep detaching from the spine. I've read it front to back many times. What Fisher wrote back then still applies to motors today: motors are air pumps - get as much in and out as you can while maximizing every power stroke.

Years ago I knew a guy that had one of those low swoopy looking kit cars. I don't remember the name of it but it was similar to a Porsche 917 - it had a stock 70 1600 single port motor and weighed somewhere around 1400# IIRC. It had plenty of zip.

Tue Oct 20, 2015 9:12 pm

So as it has developed, another motor came up for sale in my area, and i picked it up on the super cheap. It's another 1300 based on the serial number. The pros are that it has a Holley 2100 carb on it, and a bosch mechanical distributor. My motor had a stock vacuum distributor. The tin and block are also in way better shape. The cons that two of the four pistons were frozen in the cylinders, but they are off already. At this point I think I'm just gonna swap my other pistons and cylinders onto it, clean it up, put new plugs, wires and piston rings in. Rebuild the carb, replace with a 12v coil. Clean/port the heads and adjust the valve clearance and run it. Im wondering based on the initial reply, if I go to use the Holley "bug spray" carb, is the Bosch distributor the better option, or the vacuum advance style? Im assuming the bosch, but that could be the inexperienced fool over here. I will be checking crank end play and connecting rod bearings. I really appreciate everyone's feedback this far. It's been motivating. What pitfalls should I expect if I follow through with this plan?

Wed Oct 21, 2015 4:44 am

A set of pistons and cylinders are about $150.....BUT you have the expense of having the heads machined. I dunno - if I was tore down that far, I wouldnt just throw a used set back in unless they were at least re-ringed and the cylinders honed. Just my 2 cents.

Fri Oct 23, 2015 10:51 am

I did mention I would be putting new rings in, and did/do intend to hone the cylinders. Going to replace the connections rod bearings too. Sorry, should have said those. Still uncertain on distributor choice, or if the Holley is even the better choice.

Fri Oct 23, 2015 4:27 pm

OLD VW NUT wrote: Here's a bit of reading for you:

http://www.aircooled.net/1800cc-vw-engine-no-machine-combo/

While thats not exactly a budget build that John outlined in that tech article the point of it is you can build a bigger motor than a 1679 no-machine motor. I built a 1641 years ago that was pretty damned fast for what it was. I ported/polished the DP heads myself using Bill Fisher's How To Hotrod Your VW book. I had the heads flycut .125" deep and a three angle valve job - I hand lapped them for a nice mirror finish. Compression ration was right around 10.5:1 compression. I had to saw the last fin off the heads to allow the cylinders to seat in the heads. I reworked the crank for max oil flow to the bearings. I installed a Norris hydraulic cam/lifters - added an S&S header and a pair of Kadron 40mm carbs. Fire came from a German Bosch 009 dist. The car was a 64 Deluxe Bug with stock gearing of 4.37. I had over-sized tires on the back - IIRC they were an F70-15" 'wide oval' something or another on stock wheels. The taller tires gave me some great gearing for the freeway. I could easily peg the speedo which went to 90mph! According to a brother in law's speedo in his 66 GTO I was doing 105 flat out when he paced me. Bugs aren't exactly aerodynamic so it was quite the speedster. The front end got real light at anything past 80mph.

I still have that Fisher book - its almost ready to be punched and put in a ring binder - the pages keep detaching from the spine. I've read it front to back many times. What Fisher wrote back then still applies to motors today: motors are air pumps - get as much in and out as you can while maximizing every power stroke.

Years ago I knew a guy that had one of those low swoopy looking kit cars. I don't remember the name of it but it was similar to a Porsche 917 - it had a stock 70 1600 single port motor and weighed somewhere around 1400# IIRC. It had plenty of zip.

The "no machine motor" referenced above actually has some clearance work, and may require the heads to be bored. It is technically not a "no machine motor". Not a bolt on change.