TheSamba.com :: View topic

Thu Dec 24, 2015 10:57 am

Since few people are discussing small stroker options lately, here is my latest idea for you to pick apart.

I recently got a '70 Fastback. It has a type 3 case dual port 1600 in it now with 34 ICTs and tuck-a-way 1 3/8" type 3 exhaust and Mexican 043 heads. I also have a Beetle with an 1835 in it, which will hopefully be replaced with a larger engine soon, so I'll have some parts to use for a larger Type 3 engine (1835's current case lacks the hanger bosses and oil hole for type 3). I also have a new CB 76mm crank and set of SCAT 5.5" i-beams.

I picked up a spare type 3 AS41 case and am thinking of setting it up as a 2021 (I have 4 AS41 cases now lol). I could just transfer my 1835 parts into this case, but wouldn't mind experimenting with more displacement. Here is the proposed type 3 engine I want to build out of it:

76mm CB 4041 crank, helicoil gear, 5.5" SCAT i-beams
AA 92mm thick-wall PCs, for 90.5 case and 94mm head. I have the cylinders now in my 1835, I'd have to buy "B" pistons.
AA 500-420 heads, 40x35.5mm valves, single HD springs, ports/chambers cleaned up. 51cc chambers (heads are on the 1835 now)
Web 163 cam, 1.1:1 rockers, CB shafts with swivel feet (have on 1835 now)
Stock flywheel, lightened/8-doweled, Kennedy Stage 1 pressure plate (also on 1835, balanced with the 69mm crank that's in there now).
36IDFs

I'd set it up for .050" deck height, which would put me at 9.5:1 CR. Instead of butchering the chambers, I'm thinking of having a machinist cut 4cc dishes in pistons to get the CR down to 9:1.

What do you think? Concerns are:

any issues with dishes in pistons?
will the stock Type 3 transaxle hold up ok without being abused?
exhaust -- is my current exhaust a big no-no with 35.5mm exhaust valve? I'm not finding a lot of 1 1/2" options, will a type 1 merged header fit a type 3? The more expensive "fix" would be buying the Vintage Speed type 3 exhaust in 125hp version.

Stan

Thu Dec 24, 2015 11:07 am

I'd do 2 things

cam on 105LC
.060" DH instead of .050"

That will work with your existing parts, bringing the CR down to 9:1 without dishing the pistons.

YMMV

Thu Dec 24, 2015 11:10 am

With regards to getting the comp down to 9.1, I would spend a bit of time unshrouding the valves instead of spending money on dishing the pistons.

Thu Dec 24, 2015 11:11 am

OR what John said :)

Thu Dec 24, 2015 11:21 am

Cam on 105LC would be a good idea, but this one I already own (108LC), and it's "broken in" with the lifters. I was thinking of re-using cam/cam gear/lifters, just keeping the lifters in the same number bores as current. I feel the current 1835 is a grunty SOB and may do ok as is, as long as I can keep it running cool.

I can play with unshrouding the valves. Maybe I can get 2-3ccs out of them without messing up the flow.

Will the 1 3/8" tuck-a-way make it run too hot?

Thank you,

Stan

Thu Dec 24, 2015 11:36 am

I couldn't tell from the OP what you had already, since you only posted what you planned.

Thu Dec 24, 2015 11:40 am

Yeah, most of this I already have, I'd just need "B" pistons and some machining. Maybe, exhaust.

Here's the car. I've been doing body work and started spraying it with Rustoleum Satin Fossil, but rains came.

Stan

Thu Dec 24, 2015 11:41 am

I'd change the DH to .060" and run it. You don't seem to be the least bit bothered by some experimentation. I think it will run great.

Thu Dec 24, 2015 11:46 am

Thank you.

How am I going to know what's happening without experimenting lol ;-)

Stan

Thu Dec 24, 2015 7:24 pm

I had one just like yours 20 years ago. It was a bit rusty so I scrapped it. Kinda regret that now...

Thu Dec 24, 2015 7:51 pm

so what is the 163? I think Ive used it before.but ...dont exzactly remember execpt for it was a way to sharp of a lobe for me. it was supplied by the costomer.so it went in after discussion and deburring. I would leave it @ 9.5 & possiably change the cam....but yes i know lots of people use it and like it. but your using it now so.....do you need or want a diferent cam??? nows the time to change. I also wouldent go above .050 deck.(personaly it would be between .030&.040 in mine). ..with that said I dont know how well the type 3 stuff cools...it looks like it should cool good but it's ugly and looks arnt everything and have zero to do with operation.

Thu Dec 24, 2015 8:43 pm

It's not very pointy, and gentle ramps, not too pointy. Nothing radical about it at all.
Set it a degree or two, or three, advanced verses what the card says. this will help retain some of the torque you lose with short manifolds.

Thu Dec 24, 2015 9:16 pm

.420" lift with 1.1:1 rockers, 249 degrees of duration at .050". Nowhere as pointy as the Web 109 I'm about to try in a larger engine. I like the cam a lot, I think it pulls great from 1K to 5K, but I'm limiting it's potential with stock rockers and 30mm vents. Would be nice to see how it does with more displacement, it would be a good learning experience.

Type 3 is a neat car, feels different than a swing axle Beetle, feels more solid and stable.

Stan

Fri Dec 25, 2015 3:54 am

Hello.
Increasing the deck height is the easy way. I would do as you menthion yourself, dish the pistons. You will get a much better burn control. The ICT´s will definitely be the limiting factor. Also I think you will get a somewhat rough idle. WRT the cam on 105 LC. Well 3 years ago I would most likely have said the same. Today I would much rather have the cam on 108 LC and ten advance the cam 2 or even three degrees. It gives better overall power. The 163 "likes" 2 degrees advance.
Exhaust is a nono. you have to increase tube size to 35 mm ID. or you will soon run into heating problems when you use the power more than just between the stoplights.
Other than that it sounds like a nice combo.

T

Fri Dec 25, 2015 7:29 am

Just don't forget the T3 is over 2000lbs vs the beetle, so low end torque is a big plus. I have a 1904cc I built, with the web 163 on 105lc from John, and it pulls hard from idle to 5k. Which has made for a great daily driver, most of the time I just use 1/4-1/2 throttle VS WOT with the 1600 all the time to keep up to traffic

Fri Dec 25, 2015 8:43 am

Congrat's on the Fastback! You'll probably very soon realize that it's a wonderful long-distance cruiser compared to a Beetle. The front axle is attached to the frame head much further apart than a Beetle, which increases the stability and ride quality. Even though it has the same wheelbase as a Beetle, you are using the full width of the body for interior space so that you are not driving shoulder-to-shoulder with your front passenger.

Car has an excellent stance now. Adding your stock bumpers takes away the "toothless granny" look in front when there is no bumper.

You should try to get your engine, either one, reliable so that you can drive it to the Type 3 Invasion next June in Prescott, AZ. I attended the Invasion in 2004 which was in Hershey PA which was just under 3 hrs from me; was a really good group.

My deep sea green '70 FB had its original fuel injection slowly die on me a year after I bought it in 2000. After some minor and not diligent troubleshooting I switched to dual carbs, starting with earlier T3 stock Solex 32PDSITs. In 2003 I tore the engine down to make it a 1679cc with full machine-in 88's, an Engle 100 cam and home-ported stock-valve heads. Weber 42DCNF carbs with 30mm venturies, stock heater boxes and an "over the top" 1 3/8" header/muffler. Ran decently but had bad fuel economy. It has mostly sat since then, even experimenting with 40IDFs and 28mm venturies. It developed an oil leak so I need to tear it apart once again. At that point I'll upgrade to a 74mm crank (for 1800cc) and the Web163 cam which I bought from AC.net a few years ago.

Fri Dec 25, 2015 9:28 am

Thank you everyone for the comments, it's very helpful.

As much as I like ICTs, I like IDFs much better and am working on on getting a set of 36IDFs for the Fastback. I'll plan on getting the Vintage Speed Type 3 exhaust as well.

Stan

Fri Dec 25, 2015 9:40 am

I went to the shop and looked through the cam boxes, it's the 163 on a 105 that I used and that sucker was sharp nosed,more than any oe cam I have ever seen. I was uncomfertable using it, but it was dfl coated and the owner was sold on it by some exspert on buss stuff. I used 1.25 rockers on it and 9.4cr and he's tickeled shitless.that was about 5 years back. I personaly dont know how it runs as I havent driven it. if you like it use what you have. but I personaly would not lower the cr below 9.3 or more deck than .045" unless you just want a engine to run on reg fuell anddont mind chamber deposits. I would also use total seal rings on it. I dont see addvancing the cam then lowering the cr below what would run good, better low end by addvancing it then lower cr and loose some mid&top&mpg&tq just dosent make sence to me.on a cam that small.bigger cam ...I could see addvancing but I am a firm beleaver on clean burn chambers&higher cr.not race car high but not low . I also like alsurps way of doing it with the 108&2 degree addvance. there are somany ways to go about all of this and even more openions. but if you like this cam now and it's good when it comes out...dissission made&done.execpt for lowering it to 9.3 with a dish of your choice.(Im going for the smoked turkey)

Fri Dec 25, 2015 10:39 am

With your big valve heads and the displacement your planning I would go with the bigger 40idf's.

Dan

Fri Dec 25, 2015 10:40 am

stan_tichomirov wrote: Thank you everyone for the comments, it's very helpful.

As much as I like ICTs, I like IDFs much better and am working on on getting a set of 36IDFs for the Fastback. I'll plan on getting the Vintage Speed Type 3 exhaust as well.

Stan
For that much displacement you should go 40 mm. the engine does not like small carbs with so short intakes.
Also don´t worry about torque. That displacement will pull the type 3 with ease.

I do not understand why people think the Web cams a sharp nosed. In fact the accelleration and decelleration rate of most of the street cams are milder than the industry standard (Engle) So don´t worry about that.

T