TF-1 92x86

[babysnakes]

I'm interested in building an engine. A hotrod so to speak for my baywindow single cab. The truck is going to be a toy, not a work truck or daily driver. I want a big engine that is very reliable. I know what I want is going to be big $s. I also have all the time I need for this build,there is no hurry. I've read up on the TF-1 case and contacted the manufacturer. I also got the chance to see one being built in person. The builder said it was one of the nicest cases he'd ever seen. I like the idea of the dropped cam to provide clearance for the crank. For some reason I came up with the idea for a 92 thick wall cylinder and 86 stroke. I have not yet purchased anything, just trying to sort out an idea. Please give me some feed back on my foolish project. I am confident I can accomplish this build correctly. Just looking for advise on this combo.

Thanks,
Erik

[Bruce2]

You don't need a TF-1 case to build an 86 stroke engine. You can do it in a stock 1600 VW case.

The longer the stroke, the greater the rod angle. The greater the rod angle, the greater the side load on the pistons. The greater the side load on the pistons, the greater the piston rock. Lots of piston rock = short engine life. IOW, an 86 stroke isn't going to be "very reliable", depending on the definition of very reliable.

[babysnakes]

Thanks, this is the stuff I'm looking for. I was going for the TF-1 because the case is already clearanced and would need no machining. Plus the TF-1 is tough as nails.

[bug66]

You don't need a TF-1 case to build an 86 stroke engine. You can do it in a stock 1600 VW case.

The longer the stroke, the greater the rod angle. The greater the rod angle, the greater the side load on the pistons. The greater the side load on the pistons, the greater the piston rock. Lots of piston rock = short engine life. IOW, an 86 stroke isn't going to be "very reliable", depending on the definition of very reliable.

But that's with the same rod..? Longer rod = less rocking of the piston. But the crank is way stronger as a short stroke

[Clatter]

HHmm.. If it was a bus it wouldn't be revving to the moon anyways, right?

Maybe, since you have the room in the compartment, go with really long rods, like 5.8 or more,
And you could run some A pistons even.. Albeit with some skirt clearancing work no doubt..

[babysnakes]

Skirt clearancing, I was looking at PCs balanced from Aircooled.net. If I had to clearance the skirts I'd have to balance all over again. I'm not stuck on the TF-1 case. I have been kicking around other options, 2180 (82x92 thick wall) w/alum buble top case from CB. Clatter, since you have chimed in I also have T-4 cases and cranks 1700 bus, 1700 914, and 2 2.0 buses cases. Weather I go TF-1, 2180 or T-4 they wont be cheap. Just looking to hotrod my single cab and trying to plan the best I can. I want it "one and done".

[wreck]

If you already have a good type 4 case then I'd build a 78x96 .Using a crank with chev journals .(cheaper rods ) . Is it an early or late bay ? If a late bay then even easier as the type 4 cooling system will bolt right in . If an early then what you save on a TF case and go to a DTM shroud . 30% bigger heads for cooling is what you need . the difference in longevity of the bottom end between a Type 4 ,an alloy bubble case and a TF 1 would be negligible . The total cost per HP wouldn't be that different .
I've a friend with a type 4 powered bay panel . 4.040 X 78 using a Mopar profile hydraulic cam(similar to a C35) 10.5 to 1 comp . 48 IDF's making 165HP at the wheels with only a 1 5/8 header . It's reliable and can be driven in 35C tropical summer days . I've a 103x78 . 180 WHP in a Ghia that is a daily driver . I've just done a little head development and a cam change from a scat C55 to a CB2300 so hoping to get a little more power .

[babysnakes]

Thank you wreck. The truck is a '69. I knew if I went T-4 I'd be going to use an upright conversion. I have Joe Cali's book and I have looked into the DTM. Is the DTM that much better? The shortest Chevy crank offered by DPR is 80mm,but The Type 4 store has a 78. I have always wanted to do a T-4 build, but I played the wuss card and was trying to stay in my T-1 comfort zone. I guess it's time to change flavors.

[wreck]

I'm using an AA 78mm with type 4 journals . no issue with the crank but I did have minor rod bearing wear at 20,000km . (Now trying KS bearings that are coated) . Over 78mm with type 1 or chev journals you need 5/16th rod bolts (not an issue) and a smaller base circle cam . the smaller base circle causes faster wear . Which probably in you case being a weekend driver would not be a big issue . AA have new bare castings of the 914 Porsche head . I'd go for those and get some good valves /seats etc to match the size /rpm you end up with .

I've had a little experience with Upright Conversions https://www.shoptalkforums.com/viewtopi ... 1&t=149141 . The cali type work OK but won't cool the cylinders evenly ,unless you fit some clever ducting to direct more air to #2 and # 3 cylinders like VW did with the 1600 TP type 1 cylinder covers .That bit of tin just below where the shroud bolts up is there for a reason. The DTM gives more even cooling which means you can run a power pulley because you engine is only as cool as the hottest cylinder .

[Bruce.m]

I've had a little experience with Upright Conversions https://www.shoptalkforums.com/viewtopi ... 1&t=149141 . The cali type work OK but won't cool the cylinders evenly ,unless you fit some clever ducting to direct more air to #2 and # 3 cylinders like VW did with the 1600 TP type 1 cylinder covers .That bit of tin just below where the shroud bolts up is there for a reason. The DTM gives more even cooling which means you can run a power pulley because you engine is only as cool as the hottest cylinder .

Hate to go OT but you’ve lost me on the 1600TP tin you mention above, & I need to know

[wreck]

On genuine tin's there is a deflector that sits over the top middle head studs/nuts .If you have a look at it ,you will see left and right are shaped differently . The deflector is often not fitted to aftermarket reproduction cylinder tins .
https://www.thesamba.com/vw/gallery/pix/1177598.jpg

[babysnakes]

Thanks for the pic wreck. These tins are sometimes plentiful in the swaps and sometimes not. Bruce, you most likely know but TP is twin port were as in other parts of the globe it is called DP or dual port.

[babysnakes]

Seeing as I will abandon the TF-1 build and most likely go for the T-4, I will not continue this thread. I'll post on the Type4um. Thanks for all the help.

[Bruce.m]

On genuine tin's there is a deflector that sits over the top middle head studs/nuts .If you have a look at it ,you will see left and right are shaped differently . The deflector is often not fitted to aftermarket reproduction cylinder tins .
https://www.thesamba.com/vw/gallery/pix/1177598.jpg

Not seen that before. Thx.
Back to topic

[Passatman]

No issue with the crank but I did have minor rod bearing wear at 20,000km . (Now trying KS bearings that are coated) . Over 78mm with type 1 or chev journals you need 5/16th rod bolts (not an issue) and a smaller base circle cam . the smaller base circle causes faster wear .

Wreck did you ever find out what really caused the rod bearing wear, could it be that the clearance wasn't right also about the small base circle cams this is the first i am ever hearing about this.