Almost time to buy a longblock...

[classicfins]

Hey everyone.. I've got a well worn, stock 1600 single port in my trike. It has a LOT of blow by, smokes often, runs through a 1/2 qt of oil about every 50 miles when running 60 mph... I wanted to buy a turn key 1776, dual port with dual carbs, etc but my money is never going to get me there thanks to everyday life and bills. So, I'm thinking about going with just a plain jane 1641 long block and replace the old worn out 34 pict carb with a new Empi 34.

My main question is this... My top speed on this thing is about 74mph.. It's really hard to run on the interstate at 70. What kind of top speed, pick up performance, etc can I expect when I get a good, tight 1600 or 1641 in this thing. Will I see a notable increase in top end/cruising speed, or should I go ahead and try to work toward a 1776 somehow? I'm not worried about hot rodding, just want to be able to run with the other guys without dogging my engine to death trying to keep up. Unfortunaly money is an issue now, but I still have got to do something before riding season gets here.

[Doug D.]

I'm running a 1600 duel port with an Engle 110 cam, which was rebuilt last summer. Good, tight motor, purrs like a kitten. My top end isn't much better than yours. 80 mph and it's wound pretty tight.

Just my opinion, but I think the problem with the VW's top end performance is more in the gearing than the engine itself. You can shop around and try to find one of the later trannys with the slightly taller gears, or look for an aftermarket ring and pinion to change the ratio. Good luck on either. The cheapest fix for the gearing problem would be to go to a taller set of back tires/wheels.

Hope this helps.

[Rsw]

Doug’s got it right. Here’s the first thing you need to do.

If it's a swingaxle it's most likely got a 4.125 or 4.375 ring & pinion...if it's 4.125, 3rd should be 1.26 and if it's 4.375 3rd could be 1.26 or 1.32.
Most IRS Type I transmissions you'll come across in the US will be AH (4.125 R&P) or AT (3.875). 2nd gear will be 2.06 and 3rd will be 1.26 99.5% of the time, so for example if you put it in second with one wheel off the ground and it takes 4¼ turns of the crank to get one turn of the wheel, you have a 4.125 R&P. (2.06x4.125)/2=4.25
If it takes 4 turns it's a 3.875 (2.06x3.875)/2=3.99
If it takes 4½ turns it's a 4.375 (2.06x4.375)/2=4.51
This assumes that 1st and 2nd gear are still stock - considering the expense involved in replacing the mainshaft to get different 1st/2nd gears, that's a pretty safe assumption unless you're dealing with a trans built by/for a hardcore drag-racer.
If in doubt you can repeat in 3rd gear, if it takes just over 2½ turns it's a 4.125, if just under it's a 3.875. A 4.375 will take either 2-3/4 or almost 3 turns depending upon which 3rd it has. Since it's not uncommon to replace 3rd with an aftermarket shorter gear, keep an open mind when using 3rd to determine R&P. The most common is 1.48 but there are many others.

Once you've confirmed what the R&P ratio is you can check to see which 4th you have, you may need to rotate the crank enough to get 2 or more turns out of the wheel to be able to discern the difference between, say, a .89 and a .93 here. Late AH transmissions had a .88 4th, earlier were all .89 unless the trans started life in a bus in which case it could be .82.


I have a 4.12 ring & pinion and a .82 4th gear. It still turns to many rpms for me on the interstate, so I am having a trans built with the 3.87 ring & pinion and the .82 4th gear. Without running higher gears, your just stuck with running slower speeds or over revving your motor.

As for the motor, stick with a 1600 or a 1641 and for get about the dual carbs. Also forget about the Empi and stick with a Solex 34. Get a hold of Tim at VolkzBitz for your carb or buy a good rebuild able core off of TheSamba.com :: Volkswagen Classifieds, photos, shows, forums, and information and rebuild it yourself.
Here’s a couple motor builders you can check into.
Headflow Masters VW's of California
Scudders Performance
Volkwagen Parts & Machining - RIMCO VW
MOFOCO: VW Performance Heads, Rebuilt vw transmissions, air cooled vw engines, air cooled vw parts

[Loner]

Stock Type I beetle motors are designed to hold their revs to about 4400 RPMs. Even though a trike is substantially lighter than a car, VW's built-in limits typically hold them to about 80 MPH, which means we get blasted on the interstates. The best bang-for-the-buck that I've found for air-cooled VWs is to salvage a Subaru 1.8L, 2.0L or a 2.2L. Those motors have close to the same dimensions and layout as the 4-cyl VW, only about 80 pounds more weight, and are readily available for very reasonable prices.

Kennedy Engineering can provide an adapter kit to mate the motor to a swingarm VW tranny, so the only engineering challenges you'll have is to install the wiring harness/computer that controls the FI, plus adding a radiator since the motors are water-cooled.

Best benefit - those stock motors are rated at 138 to 180 horsepower, more that double the stock VW powerplant! You could get by for about six to eight hundred bucks out of pocket for the adapter kit ($430) and motor if you're careful when shopping for a motor.

[classicfins]

Great stuff guys.. Let me ask another question. If I just go with a stock 1600 would it be to any advantage to switch from single port heads to dual? Or should I just stick with a single port setup?
Doug

[Rsw]

Stock Type I beetle motors are designed to hold their revs to about 4400 RPMs. Even though a trike is substantially lighter than a car, VW's built-in limits typically hold them to about 80 MPH, which means we get blasted on the interstates. The best bang-for-the-buck that I've found for air-cooled VWs is to salvage a Subaru 1.8L, 2.0L or a 2.2L. Those motors have close to the same dimensions and layout as the 4-cyl VW, only about 80 pounds more weight, and are readily available for very reasonable prices.

Kennedy Engineering can provide an adapter kit to mate the motor to a swingarm VW tranny, so the only engineering challenges you'll have is to install the wiring harness/computer that controls the FI, plus adding a radiator since the motors are water-cooled.

Best benefit - those stock motors are rated at 138 to 180 horsepower, more that double the stock VW powerplant! You could get by for about six to eight hundred bucks out of pocket for the adapter kit ($430) and motor if you're careful when shopping for a motor.

Or you could just get the transaxle that I am having built for $850.00 and not worry about adapter kits, computers and wiring and be done with it.

[chromedome1964]

Great stuff guys.. Let me ask another question. If I just go with a stock 1600 would it be to any advantage to switch from single port heads to dual? Or should I just stick with a single port setup?
Doug

On a stock 1600 you will see almost no difference in single and dual port heads horsepower wise, but the single ports make a bit more torque low in the rpm range. If it's stock, stick with the single ports.

[DeathBySnuSnu]

I run stock first and second. A 1.26 third. A 0.82 fourth. And a 3.44 ring and pinion. It is a lot of gear and i don't think a stock engine would pull that much gear. If you want a set of 3.88 r & p. I have a spare set just laying around right down I20 from you.

[classicfins]

I run stock first and second. A 1.26 third. A 0.82 fourth. And a 3.44 ring and pinion. It is a lot of gear and i don't think a stock engine would pull that much gear. If you want a set of 3.88 r & p. I have a spare set just laying around right down I20 from you.

Thanks, but the more I read and think about this, the more I think I'll just got with a stock 1600, maybe 1641 and leave the transaxle as it is. I am wanting to build a whole new trike from scratch about a year from now, and I think then I'll play with some different setups.

[classicfins]

On a stock 1600 you will see almost no difference in single and dual port heads horsepower wise, but the single ports make a bit more torque low in the rpm range. If it's stock, stick with the single ports.

That's kinda what I thought. Thanks

[DeathBySnuSnu]

If you have the 4.12 r & p then changing tire diameter would be the easiest way to go if you are nearly stock. I had a self imposed tire size limit. So i did the re gearing.

[aussiepilch]

Thanks, but the more I read and think about this, the more I think I'll just got with a stock 1600, maybe 1641 and leave the transaxle as it is. I am wanting to build a whole new trike from scratch about a year from now, and I think then I'll play with some different setups.

Good idea Old Mate and while you are at it graft a Subaru donk into it and you will never look back.
Big thing down here now maybe because of the heat or then it just might be for reliability. I run a 1776 with a 120 cam but I have found it a big mistake (cam) behind a 3 speed auto, have to keep the revs up but no clutch so am always droping down a gear.

[classicfins]

I've been looking at the subaru setups and that seems like the way to go. I may do something like that on my next build. I'm wanting to build the next one, longer, lower, more stretched out, and I want it to scat!

I also have a 2000 Honda CRV suv (FWD) that has been totaled from the rear. I am thinking about running the engine/trans from the Honda. It's a pretty good chunk of weight, but plenty of power, and built low and stretched out it should move down the road pretty good.

[Rsw]

I run stock first and second. A 1.26 third. A 0.82 fourth. And a 3.44 ring and pinion. It is a lot of gear and i don't think a stock engine would pull that much gear. If you want a set of 3.88 r & p. I have a spare set just laying around right down I20 from you.

Where did you get the 3.44 R&P at?

[DeathBySnuSnu]

The 3.44's came from Rancho Transaxle. They only come in splined shaft style. You have to convert / change to splined gears to match the pinion shaft. It takes a different bearing also but Rancho has a conversion / adapter bearing race that makes it fit the case.

classicfins:
Sound like a good plan.
The VW's were geared so low due to the low hp they had back in the day. They were intended to be an economy car. If you put a modern engine like the Suby on the VW transaxle you will still have the same gearing. You will have more HP and torque for sure. But if you were turning 4000 rpm at 70 with the VW engine, then you will be turning the same with the Suby. The Suby can just handle it better / for a longer time.
I put a lot more HP on mine (165hp) and then re-geared to make the hp increase more usable to me.

[matman1972]

Sound like a good plan.
The VW's were geared so low due to the low hp they had back in the day. They were intended to be an economy car. If you put a modern engine like the Suby on the VW transaxle you will still have the same gearing. You will have more HP and torque for sure. But if you were turning 4000 rpm at 70 with the VW engine, then you will be turning the same with the Suby. The Suby can just handle it better / for a longer time.
I put a lot more HP on mine (165hp) and then re-geared to make the hp increase more usable to me.

Agreed, we went through changing gearing on 4th with a stock 1600, and not even being able to pull up hills on the interstate in 4th due to lack of power, making the gearing useless. changed it back and enjoyed the 1600 for a while before finally deciding to go with a 1915, and put the taller 4th back in. 4th is now a comfortable 75-80 with almost no need to downshift on highways at all anymore.
Deathbysnusnu, I'm not making quite as much hp as you (around 105) and I usually feel like I have plenty. I am thinking however, that when I hit the time when my 1915 is getting a little worn, about going a little larger. I'd just like a little extra oomph on longer hills, and for passing. Got any suggestions on stroked crank size that will run nice and smooth for long trips?
BTW, I love your user name. One of my favorite shows ever.

[Rsw]

Agreed, we went through changing gearing on 4th with a stock 1600, and not even being able to pull up hills on the interstate in 4th due to lack of power, making the gearing useless. changed it back and enjoyed the 1600 for a while before finally deciding to go with a 1915, and put the taller 4th back in. 4th is now a comfortable 75-80 with almost no need to downshift on highways at all anymore.
Deathbysnusnu, I'm not making quite as much hp as you (around 105) and I usually feel like I have plenty. I am thinking however, that when I hit the time when my 1915 is getting a little worn, about going a little larger. I'd just like a little extra oomph on longer hills, and for passing. Got any suggestions on stroked crank size that will run nice and smooth for long trips?
BTW, I love your user name. One of my favorite shows ever.

What R&P gear was you running with the taller 4th gear. My stock 1600 pulled some pretty big hills in WVA with the 4.12's and the .82 4th gear.

[DeathBySnuSnu]

Hey matman1972:
So as to not completely hi-jack classicfins thread I will start a new one. Strokers.

DBSS

[matman1972]

What R&P gear was you running with the taller 4th gear. My stock 1600 pulled some pretty big hills in WVA with the 4.12's and the .82 4th gear.

I'll check. I had a guy named Ron Hunter build the engibe and transaxle. Plenty of power, but I would like a little more pickup in the 80-90 mph range.... or maybe i just need to slow down.

When we were waiting on the engine to be built, we put the old 1600 in it for a little while. I had the new transaxle in it with thetaller 4th but that engine was not all that healthy to begin with. Changed out 4th thinking we wanted stock but when the new engine went in, it was pretty obvious we wanted the gearing changed back for highway use. Your 1600 is probably running a lot healthier than that one was.