2084 Turbo Build

[John S.]

It only gets easier if you own a rail, Baja or buggy. Lol
I miss my buggy

[kangaboy]

It only gets easier if you own a rail, Baja or buggy. Lol

Yeah, I got a couple of them lurking around the property as well. There is nothing quite like jamming a turbo setup into a full bodied beetle...really makes me appreciate doing ANY work on the rail buggy
The thing that really gets me, it the fact that half the top end of the turbo motor has to come apart to do any kind of work on something that was a 10 minute job when it was a stock build. Oh well, it makes it all worth it when you get it back together and take if for that first test drive and nothing else breaks

[kangaboy]

Took a couple hours this weekend grinding out the combustion chambers a bit more and doing some more cc-ing of the heads. So funny story, the first two syringes we used to cc were kinda bum, and didn't really read appropriately. After getting my hands on some surgical grade syringes, and actually weighing their water contents on a scale compared to what their graduated markings read...we came to the conclusion that while we thought we were nearing 60cc chambers the whole time, the previous syringes were reading off by about 5cc's...so as it stands now, we have 55cc chambers (confirmed). That was a kick in the nuts, but whatever, I was going to use barrel shims the whole time to increase deck height anyway, so better to find the correct chamber volume now, instead of finding it a month down the road when I scorch a piston thinking my compression ratio was lower than it was.

Don't judge my work by my pictures TOO much...they still retain the general shape of the original chambers, and the majority of the additional cc's came from the spark plug side of the exhaust valve , and general blending and unshrouding of both valves.



After the cc-ing was completed, we did the final assembly of the valves. We went ahead and just did both the inner and outer of the CB 650 dual springs. I figured the cam was going to wipe or not on the first start up, so a little more spring pressure shouldn't matter. We have appropriately matched lifters and used the supplied lube...so just gonna send it and hope with the appropriate break in procedure that the valve train will survive and give me many miles down the road.



Just to note, the keepers were ground and a 0.030 valve spring shim was installed prior to assembly.

Ordering 0.060" barrel spacers today and we will have a deck of .099" and a compression ratio of 8.26:1...a .070" spacer will give .109" deck and a compression ratio of 8.01:1 though...so as I'm typing this now, I think I'll have to ponder on this a little more. My original intention was to get as close to 8:1...

The next fun task is getting these CB 1.4:1 slipper foot rockers shimmed appropriately to allow rotation, but keeping the side play to an absolute minimum. They only supply you with so many shims, so it's kinda like a puzzle.

[buguy]

All you can do is run it and hope for the best. Only real way to learn is by doing it. I bet it will be just fine.

[madmike]

I'd run .060 spacer and a .010 copper head gasket,, I've even re-use them coppers, just heat'em up and they re-seal just fine
I look at it like this ,, a ten dollar set of coppers are cheaper than Heads ,,if I torch one

[kangaboy]

Well, seems like I may have to take a route like that Mike. Apparently no one has .070" shims in stock. For what ever reason...I assume Covid supply issues...there is a shortage of .070 and .080 shims. I can't source any online.
Are you implying that the copper head shim would somehow save a head? Or are you just saying during the reusing process, that if you accidently over heat one, you can just get another set for $10?
For the time being, I know my heads and cylinder barrels are perfectly flat, so I have no concern about the combustion chamber sealing. With that logic, and the fact that I have a set of .020 barrel shims on the work bench, I may just order a set of .050 shims and stack them up to get my .070". It's not ideal, but from a wallet sense it sure beats getting a custom set ground from Rimco/FAT for $125

[buguy]

I have mine stacked too. I don't like it, but it is what it is.

[madmike]

Yes the gasket will melt before the head does ,, never had any issue with sealing ,, I lap them with valve grinding compound also

[kangaboy]

Yay, update!!!
Finally got the 0.030 and 0.040 cylinder shims in that we needed to get the motor to ~8.0-1 compression ratio, and after mixing and matching them for quite some time, we got 4 similar stacks ~0.070”.

NOTE: Sorry these pictures are annoyingly big...I'll try to keep them "scroll" friendly next time





Shims in, push rod tubes in place, heads bolted down.



Gland nut was next after we had a good handle on the compression ratio…which was the most time-consuming thing on the build. After finding a nice 6pt 1 ½” socket to fit the CB Gland Nut, Jim performed the art of applying body weight to a 2 foot breaker, so were looking at roughyly 370lbs-ft of torque. End play set at 0.004".



Next was push rods. I have the CB dual tapers so Jim threw them on the mill and got them all chopped up and looking real nice. A couple firm and what you might think were excessive whacks with the brass hammer on a Delrin block and they were all ready to slide in their new homes.




Bolting down rockers was a treat. Those 650b springs are pretty durn stout. After that, we slapped the valve covers on (with just a liiiiittle bit of contact from the 1.4:1 rockers without the cork gasket in place), and lugged it out to the GTI to take back to my garage where the beetle was waiting.



I got the clutch and PP in place with the help of a torn down transaxle from a couple weeks ago. Looking forward to seeing how the Kennedy Stage II pressure plate and the Copperhead disc hold up to the new motor.



Somewhere along the line of building the motor, I removed the rear apron….man oh man does this make things easier…and I wish I had done it years ago.





Slid right in with plenty of room to work around in. What a treat.
I got the motor dressed with just a couple things after I got them cleaned up from their previous use. Also tried to put the header on, just to see how it lined up from the previous 1776 build. Seems its just about ¼” wider. I plan to just heat up the header at the two curves and bend it into place. I’m also thinking about relocating the wastegate like so many have done previously. It really gets in the way of the sled tins on the 1/2 side and just kinda seems out of place. It was fully functional, but that doesn’t mean it cant be improved.





Next steps is just getting tin cleaned up and painted, and getting all the top end swapped over from the 1776. I have just a few parts on order and need to get a few oil lines situated, but I'm optimistic in getting this thing on the road in the next week or so. I'll have plenty of downtime this holiday week, so I'll see how far that gets me.

[madmike]

Location? I don't recognize that license plate
Great Idea to re-locate the wastegate

[kangaboy]

It's weird that I have St. Louis listed in my profile under location, but it's not showing up under my avatar anymore.

[madmike]

[kangaboy]

Finally got everything put back together this weekend to try and get the cam broken in. It was a nerve wracking couple hours making sure all of our ducks were in a row prior to turning it over. My biggest concern was hoping that the 1776cc tune would work to keep the 2084cc alive long enough to give us a 2000rpm/20minute break in. Took us a little bit to get enough battery power to turn the fresh motor over fast enough for it to catch, but after we got that sorted, and added a little more fuel to the map, she kicked over and we got a 20 minute break in!



We primed the lines prior to trying to start it, and once it started, oil psi shot straight up to ~60. At the end of the first 20 minutes, pressure hung around at ~30psi at 2000rpm...so cant be disappointed in that. I couldn't get it to idle with the current tune, so I don't know what the idle pressure is, but will work on that after I get the oil changed and check valves. No weird sounds during break in that would be cause for concern...but MAN are those straight cut gears loud. Left our ears ringing...

I drained the oil while it was still warm and then ran a magnet through it. Just a little bit of grit, but nothing that suggests failure anywhere. I'll cut the filter open just for reassurance.



I have a lot of "it'll work for break in" loose ends to clean up before I can take it out and seat the rings, but now that the bottom end is broken in I feel like a huge weight has been lifted. Time to get things buttoned up and see what this new beast can do

[Schweg]

Nice! I was just wondering how this is gonna work as I start to build a new EFI set up and engine so your post gives me hope.

Are you gonna run it at Gateway?

[kangaboy]

Are you gonna run it at Gateway?

That's the plan!!! I looked up the track date the other day and I think it's scheduled for April 10th. Should be ready to rock by then and get some time slips to see how we're runnin'.