Winter 2176cc Prerunner-Style Engine Build

[jimmyhoffa]

I'm starting an engine for my Chenowth Buggy that will be in my weekend warrior/high speed nature exploration car. It sees open sand washes and road use (street legal) and also needs some decent torque for climbing rocks in Moab trips and frequenting Colorado.

I already have a lot of the parts, and have played with several engines in my car enough to know what I want. I have a built 6-rib so I'm not super worried about transaxle preservation.

STUFF I HAVE:

Early CB aluminum case-stroker clearanced and 8mm case savers, center main shuffle pins. OEM VW oil pickup tube from a late scrap case.

CB 78.4mm 4340 crank, lightened 8-dowel flywheel with Berg gland nut

Scat 5.5 I-beams

Mahle Motorsport forged coated 94mm pistons in Cima 94 barrels

MOFOCO 042s buttered up + back-cut intakes to flow almost exactly the same as NON-CNC Panchitos (for the sake of discussion) with a ~63.5cc intake port

58cc chambers after re-work

Engle FK-42, Engle Phosphate Lifters, Magnum Straight-Cut Cam Gear set

Scat Slipper Foot 1.33:1 rockers with the 3/8" adjuster cups

Could get Spanish Weber 44IDFs, may dry sump float bowls. UMP aluminum intake boxes. (Optional intake is a Single 44IDF with a Tubular FAT or Cast CB center, and Guido Wensing End Castings matched to the MOFOCO 042 ports. This limits cam duration and pushes me away from something like a Web 163 towards the FK-42 for similar power profile with less .050 duration, at the expense of clatter and valvetrain life)

Ruddock's Pushrods Done Right and Beehives Done Right

CB 26mm Maxi-Pump Full Flow

Clark Callis' Heavy Duty Cylinder Tin

Here we go! I built a nice transmission and I'm being too easy on it. Time to crank the dial up a few ticks.
_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[Brian_e]

Doll up the heads some more to get them up into at least the 170cfm range. I would work the area above the guide boss, and then do a really good valve job with a nice big 4th bottom cut. That won't increase the port volume all that much, and you should pick up a bit.

I would stick with the fk42 cause you have it, and it will work good.

No way on the unheated FAT intake.

1 1/2" header and 9.5:1 as well.

Sounds great other than those few things.

Brian
_________________
www.type-emotorsports.com

[jimmyhoffa]

Ah yes, I have both an Al's Headers 1-5/8 race exhaust and a Tri-Mil 1-1/2 with a few muffler choices there, so I'll have plenty to play with.

I can get to 9.4:1 CR with a .040" deck so it looks like that problem solves itself.

The heads are at 164CFM at .500 (25") and 4 of those additional CFM came from the intake back-cut! Nice Easy money, baby! My I/E at .500" lift is 76.2% now. (125cfm exhaust flow) I'll have to decide if I want to try to break into the 170s at the expense of being compelled to touch the exhaust a bit more to stay in the Magic I/E Window.

With the FK-42 and 1.33's I'll be lifting right at/over .500" so those numbers are somewhat meaningful considering how fast the FK-42 gets the valve there.

I can maybe touch 125HP with a fat torque curve in any reasonable state of tune and I think that'll make me happy. It's "pretty fun" right now with my ~90HP in a 1300lb car. I've always believed 10:1 LB/HP is a tipping point, of sorts.
_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[Alstrup]

I think the heads flow sufficient for the centermount set up. But of course, if the seats can be improved it is "free" lower rpm torque especially.
If you go with dual carbs, keep the split rocker set up and go up in exh size.
_________________
https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[jimmyhoffa]

This build, like so many others, is now being influenced by supply chain issues. This might be one of those Dark Years builds where you look back in 10 years and try to remember what the hell you were thinking, until you remember the context. "It was a different time"

That FK-42 cam I have is on an SC-1 blank, and there is a small crack through the thrust flange on the inboard side. It's going to K.O. the thrust bearing faces immediately, and likely propagate quickly and result in a fractured cam. I expect I'll be taken care of by either one of our trusted vendors here, or Engle themselves.... who are currently both powerless to supply me another. Fair enough. You can't grind a cam out of air.

The plot was twisted slightly a few days ago when I got sent to San Diego on work, and checked two empty suitcases on the flight out, and then Southwest Airlines politely transported back 96.4lbs. of VW parts. I put all my clothes in my carry-on and threw away some of my undesirables at a hotel in Solana Beach.

The loot? 2 rebuildable model-similar 44IDFs, Redline linkage, CB cast air filter bases, an Old School set of UMP intake boxes for dual IDFs, Redline offset IDF manifolds, a WEB 218 and an Engle 100 on EP12 blanks, a SCAT fan shroud, 2 cam gears, some CNC brake rebuild parts, 2 type 4 stock carbs for a buddy, some engine tin for Kangaboy on here, 2 stock DP heads for a spare build, and a cool old school ring spreader tool. Here is a fraction of that as I was packing. There was more but I forgot what. I kinda lost my mind a lil bit.

Here's my half disassembled IDFs. Throttle shaft bores are good, bearings crusty. No problemo!

I had it in my head (because of some old tall manifolds I had) that Dual IDFs wouldn't fit in my car, and that turned out to be a big fat lie. The San Diego offset manifolds simply marked "B" position the carb juuuuust so. I'll even be able to fit my airboxes. So now I can try both my Wensing big end casting setup and my duals with the greatest of ease. The dual IDF stuff I had arranged to pick up if I ever made it out there, and luckily I did! I committed to buying that setup based on a hunch that the manifolds that Redline says WILL NOT clear a stock fan shroud would result in the IDF bodies being closer to the shroud and clearing my rear cage bar. They do!

_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[jimmyhoffa]

Regarding the WEB 218 vs. The FK-42 cam: It doesn't look like I'll be missing much. I have been running the 218/119 VERY reliably in another engine, hard off road as well as commuting, so I know the 218 to be quiet and reliable with 1.1:1 rockers and Porsche swivels.

DubDyno is of course a very rough estimate that leaves a lot of influential variables "out in the wind" but it is what I call directionally correct. If you under-head and over cam, it shows a very peaky engine that runs out of flow right as it comes on the cam. If you over-head and under-cam, it shows the torque loss. Exhaust way too big? torque loss. It's probably nowhere near accurate but it's fun to play with for $1.99 and would be great to teach a novice the basics. Gave me something to do on the plane.

218 with 1.1 versus (faded) fk42 setup

218 with 1.25 versus (faded) fk42 setup

So, I'm probably not missing much and it's a known quiet cam the way I have it set up. In addition, thanks to a lucky local purchase I now have a nice 1-5/8" Al's U-header, and a 1-1/2" tri-mil U-bend exhaust.
_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[fastfil]

Power where you need it - not just chasing a number. Looking good!
_________________
"...swingaxle...transaxle...same diff."

[jimmyhoffa]

We're moving right along here now. I got the 'Rona and it hit me hard, so I lost a few weeks of my life thanks to that. During my recovery I just had the energy to sit there and tinker and not much more, so I busted out the arts and crafts supplies to make my bolt-in sump baffle. First in CAD (Cardboard-Aided-Design)

Next, after some careful cardboarding, I moved up to the 3D printer:

THEN, after printing and tweaking several times, it was time for some cold hard steel:

Bolt location on the cam gear "wall" to hold the sump baffle in place

I have the cam degreed in after a few mock-ups and all of the cool parts like the pulley and reinforced alternator stand stolen off my other engine, so it looks like sealing up the cases is next. I had the CB crank and a stock crank balanced, and the CB crank was actually further out of balance than my stocker for my buddy's engine. It needed 7 grams off on the pulley end, but the flywheel end was floating around +/- 1 gram so it was good. The stocker was out 3 grams on the pulley end and 2 on the flyweel side. Probably would have been good for its purpose but we got it below 1 on both ends because it was already on the balancer.
_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[jimmyhoffa]

As for nifty parts, I have a nice low mileage set of Magnum straight-cuts I'll be running:

I also procured, from several sources, a full MSD setup with the medium/high power coil, and it came with the curve tuning kit. I have several RPM chips for the 6ALN unit.

I am giving the MAHLE North America forged coated pistons a shot. They seem very well made and I'm looking forward to fitting them.

_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[modok]

I always enjoy watching your progress. Should be pretty hot unit.
Collector volume and length on most of these off-road tri-mill types of headers might be far from ideal. You might think about experimenting with that someday.

[jimmyhoffa]

Thanks! Means a lot coming from you. I heard you've rebuilt a few engines in the past. I have a new dilemma which is that I have a perfect set of Cima 94mm cylinders and a perfect set of AA 94's as well. Which to use? The Mahle top ring is 1.2mm Nitrided stainless FWIW.

For now, here's a picture right before I added more center main assembly lube, more/smeared cam lobe lube, and sealed 'er up! I have gotten super good at the application of Permatex Aviation. Torqued up, the cases have that perfect little "bead" of barely visible brown goo with no dripping or running anywhere. The picture makes it look like a lot more than I actually put down.

_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[chrisflstf]

No orings on center case studs?

[Brian_e]

You already did all your rocker geometry?

Trimmed the head studs to length?

Brian
_________________
www.type-emotorsports.com

[jimmyhoffa]

Center case studs are shuffle pins with no provision for O-rings.

Rocker geometry is sorted, I had some "throwaway" steel pushrods of dubious origin to make a mock-up pushrod to dance around with and check. (I am using CB's 1.25:1 rockers.) I'm waiting on Ruddock's super-duper pushrods and Beehives. I think there's some sort of hang up with black-oxiding his new version spring retainer.

Head studs ended up needing no trimming, I restored some OG 8mm studs. The thread quality is just so high on those it's hard to ignore. I bought some Brazil 8mm head studs from Berg and I guess they're fine but I'm going to use them on my buddy's engine for his beater buggy. I just don't like them as much. Threads feel looser, they're unnecessarily long, and they're softer by a little.

The 94mm cylinders needed a .030" base shim to get a tidy .042" deck all around so that was easy breezy! Both my AA's and my Cimas are exactly 114mm long I just have to figure out which metallurgy I think I like better for this purpose.
_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[jimmyhoffa]

Wow, so that escalated. After a brief 6 month delay I am making good headway here. Aggressively so, I'd say. I ended up waiting a while on miscellaneous dumb pieces, and I was able to change heads to something new I wanted to try.

I worked with our very own Type E motorsports and am very fortunate to now own these AA502 heads, which Brian has flowing 172.9 CFM @ .500" and 179 @ .600" with a 70cc port volume. I think this was the biggest shift in the whole build. I'm lifting to .510" with my Web 218 and 1.2:1 stock style rockers with Mahle/Porsche swivels.
On to the top end: Unfortunately, since my rocker/cam combo is very much not "Dan Ruddock Approved" I was unable to use his pushrods for this build, since the longest ones he offers are too short. No biggie at all, I needed a little more pushrod tube clearance and I'll use his VERY NICE BRICK SH!THOUSE pushrods on another build without a doubt. They only came up .125" short, but I ordered them before the head change and all that, so I'll transition them to another build. They looks extremely stout, stouter than the dual taper design for sure, particularly due to the side of the land of the tip. CB/Manton dual tapers it is for now, then! Cut and assembled them in my nice new mill in under 15 minutes. I started after my wife got in the shower and finished before she was out.

Now it was time for some top-end assembly and mock-up. This was all figured already, so it was a assemble-n-torque situation. I skim, very lightly, a coat of Permatex Right Stuff Gray on the cylinder base and shims, and then dab a mini-blob at the studs on larger bores. I'm careful to form the cylinder deflectors just so around the cylinder profile. I have a teflon bar I just roll up the side of the deflector to form it, takes a little under 5 seconds each.

Next, I have two ignition systems I want to run, the MSD and my CB Magnaspark, and they both mount differently. I used a long distributor stud and then the spacer I machined from a bicycle axle spacer either serves as the standoff for the MSD straight clamp, or the spacer for the CB stepped clamp! YOU'RE A WIZARD, HARRY!

_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[jimmyhoffa]

Moving along here, I got it pretty much good to break in except for wiring and some very miniscule plumbing. Ignition for break in will be the centrifugal CB Magnaspark with their wires and coil and plugs.

I got that mocked up enough to take it out of the basement, around the house, and up to the garage for install! That... was not straightforward since my usual "easy button" (my Bobcat) is out on loan to a good friend. Instead, I decided to push the sketchy button. I'm a good bit under 200lbs and it wanted to nose straight over if you touched the front brake.

Then I got it in the car, installed some plumbing and random sensors after I made my oil temp plate and the -8 AN hoses.

_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[oprn]

I am just curious about the "winter" part of the title as that is what caught my eye on this thread. Nothing so far about winter so - is it just that the engine was built during the winter? Or is it going to be run in the winter weather?
_________________
We had the stone age, the bronze age, the industrial age and now we are in the age of mass deception and mind control for corporate profit. (The mass media age)

[jimmyhoffa]

The plan was to build this over last winter and run it all summer, but parts shortages and problems with the parts I did have turned this into a year-long affair because people don't want to work these days, so we can't have cool stuff anymore.
_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[jimmyhoffa]

Frustration level is at an all-time high here - hoping to break this thing in tonight if all the stars align, which they almost certainly won't.

First off, I went to plumb this filter up and it looked totally great. I was using a Derale brand remote filter mount. Maybe Chinese cast and U.S. finish machined? but more likely cast and machined in China. Spent forever porting and de-flashing it, plumbed it in and went to screw the filter on, and....

Well that's not gonna seal. Figures, the ONE TIME on this engine where I was like "whatever, I'll just get the China one it'll be fine I'll get a Setrab or something after break-in." Good news! I bought the CB performance branded equivalent for a customer engine, and BAM! Great news, it's also trash. It was tapped on an angle too! A-maazing surface finish!

So, I got that figured out by re-machining the Derale one and making a custom nipple for the filter to thread onto and now no spark.... So... now I'm trying to figure that out. EVERY SINGLE problem I hit basically takes me a day to fix. It has got to be just a maximum pain experience trying to make money building these. Never have the words "Labor of Love" meant more to me. You gotta WANT IT if you're going to build performance VWs these days.
_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[Dan the workingstiff]

What a POS!
The quality of that piece is embarrassing. Sorry man, that sucks
_________________
'69 Beetle
'66 FG buggy
My other air-cooled's
'76 IH 1200
'75 IH 1200