Will it live?

[Bob Brugge]

If I effectively double the hp/torque of my engine, will my tranny live?
70 beetle stock everything, wanting to go 1800 to 1900 cc motor build. The trans runs fine now, and the axles seem like they are in good shape, but the mileage and wear on them are unknown.

My other question is this: If I use shorter rods, say 40 hp rods so I can go 76 or 78 mm crank with A pistons, which option is the best short of trying to find rods with a bigger wrist pin hole?
Option one is use a rod with no bushing.
Option two is to use 40 hp rod bushings in the pistons and having the wrist pins turned down 2 mm, but will they still be sturdy up to say...5k rpm?
Option 3 is to have the center of the wrist pin turned down the width of the bushing and press it in when the wrist pin gets pressed in, but same question, will it be sturdy at say 5k rpm?
I know I can get lightened gudgeon pins, and I read on here that I can get 40 hp rods with the bigger 22 mm wrist pin bushings. Can't find them anywhere tho. Just not sure what is going to be the most cost effective solution.
My goal is to follow John's recipe for an 1800 cc motor. A motor that is real close to stock width. My theory is that if I can use 74mm crank, 5.325" rods and A pistons, I should be able to use 40 hp rods with an even bigger crank, say 76 or 78mm, still have a stock width motor but be able to get another 50 or 100 cc's out of it.

Or am I dreaming out my ass?
_________________
Keep on Dubbin'!

[modok]

I am glad you are thinking about it, but it's not going to be cost effective to pay other folks to do custom work for you, when you can make a 88x78 or 90,5x78 stock width with all off the shelf parts.
i might consider making shortened rods, but it will not cost less than new Chinese rods. Modified stock rods might run 200$....total for lightening, balancing, re-sizing, and boring for new bushings or shorening 1600 rods. if you could have cb H-beams for 50$ more.....then do it! Why would you not?

I agree, 74 stroke and 5.3 rods should be a nice combo, but further shortening of the rod the piston will be running into things worse and worse, so isn't practical.

late 40 horse rods should be common in Europe.......hey i know, call Roy at Mofoco... DPR, those guys have a lot of cores!

88B pistons are available from some sources, possibly berg, old guys, the classifieds, and so forth, but you will need a 80mm stroke, and is that a bad thing? I don't know.
B pistons are 35 or 34mm pin height, so stock width with 78 or 80 stroke
How big do you want the engine? Are you limiting yourself to tiny carbs, heater boxes, or something?

[Bob Brugge]

[ach60]

Study the Engine combos at CB Performance to get an idea
http://www.cbperformance.com/Engine-Kits-Engine-Parts-s/39.htm
Stroking a VW motor is not a easy job, even a 74mm stroke requires design and planning for success.
With Thick wall 92mm Pistons & Cylinders I don't see the point of using small bore P&C sets.
Stock width or close to stock width is a matter of planning your build with A or B pin heights with your desired stroke, and rod length.
You have Stock 220 mm to work with from the crank centerline to the top of the Cylinder.
The amount you Piston sticks above that 220 is how much more shim you'll have to add.
There are some beautiful tables in the Forum that factor this all out in 4 color glory, I'll search to see if I can find them, and post them.
_________________
Good Luck
Al

[modok]

The cheap AA rods are quite terrible, I would not recommend them. I have run them, but that does not mean they are good, it just means rods are not as critical as most think.

Yes the bottom of the piston runs into the case and crank. Very common for 40 horse engines for the #3 piton to hit the case shelf at BDC, and it's not even a stroker yet, just stock, or big bore kit.


I have a 2007cc engine that has lasted 75K miles and still going......... 88 or 90.5, not a big difference, but it's narrower than stock since the heads are milled, but uses stock lengh pushrods since I have porsche swivels, so

what part of the engine needs to be stock width?
the tops of the pistons?
pushrods?
exhaust ports?

[vwracerdave]

You would have been a hell of a lot better off building a 1835cc or 1915cc with a stock crank & rods than playing around with those 88's and 74's. A $100 set of I-beams rods are plenty strong enough for your needs.

A stock transaxle will handle daily driving the100 HP you are gonna get out of your 1800cc engine IF you do not have any wheel hop, do smoky burnouts, or dump the clutch doing drag race starts.
_________________
2017 Street Comp Champion - Thunder Valley Raceway Park - Noble, OK
2010 Sportsman ET Champion - Mid-America Dragway - Arkansas City, KS
1997 Sportsman ET Champion - Thunder Valley Raceway Park - Noble ,OK

[modok]

IMO AA makes cylinders and pistons, forget the rest. I mean it.
You want LONG service then you need OE or better components. Scat rods are decent. mexico heads, good bearings lifters and cam.

Stock rods, re manufactured well, should cost at least 120$
I see them for less, but they suck. They don't know what they are doing.
I'm tired of it.
Bushings loose, not aligned, not balanced, all different lengths. Do it right or don't do it at all.

[YDBD]

As racerdave stated the stock transaxle will handle it. But add solid mounts for the transaxle and straps to hold it in place.
_________________
'56 pan Dune Buggy since '69
don't live in the past...but when I did:
'67 bug
'64 baja
'60 dune buggy
'73 Personenkraftwagen Type 182 "Thing"

[oprn]

Rule of thumb back in the '70s used to be that stock trans axles were good up to 150 HP. That was before the big Bus ones came out.

[[email protected]]

idiots can break a crowbar in a sandbox while naked. If you aren't an idiot the trans will hold up to this power level, no problem. Just make sure you don't "launch" the car, and don't have wheel hop.

Also, I feel it's a better idea to simply bore the engine for 92s or 94s, and use a bigger piston. These ARE available in B pin height, so you have more flexibility with strokes and rod lengths to get what you need. It will cost the same in the end, shipping 2x (to/from), and the actual machine work.
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[Multi69s]

A stock transmission will handle it fine as long as you don't launch from a start. My 2110 DD has about 75K on it, no problems, and I'm using rubber mounts. I don't know if Berg still has them, but they are his heavy duty models. If you drive it like a sport car and not a dragster, you can even get by with a stock clutch.
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
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[Alstrup]

A couple of things.
If you just want to double the hp of a stock 1600 , why go to all that trouble???
Also, the 40 hp rods are rather annoying to install. If you absolutely want you can rebush them to accept 22 mm pins, but i don´t see the point in such a build. And as Modok states, there will be a lot of other issues during assembly.
If you have the heads ready for 88 mm thick wall cylinders and they are massaged to support the power go with John´s 74 x 88 ministroker kit using H beam 5,325 rods.
Use the Web 163. Set CR to 9-1, Use a set of 36 mm Dellorto or Weber IDF. Use a good exhaust. F.I. a regular 1 3/8 header with a good muffler (NOT the typical cheapo thunderbird type) or maybe a CSP super comp. or a 1½" A1 sidewinder.
If the heads are done well this will pull 100 hp easy.
I agree with Dave though. a 1776/1835 would do the same, maybe with a hairswith less bottom end torque.
AND,,, of course, balance balance balance.
If the trans is decent it will hold 100 -120 hp with out problems. Use the rubber mounts from WW. They are good. It will be a good idea to replace the rear transmission brace to a beefed up one. Empi has them at a decent price. Use the upper brace, but once it has been clamped down for getting the shape, loosen it so it doesnt mash the rubber mounts but still supports the trans housing and you´ll be good.

[Alstrup]

Just for shiats & giggles I let the analyzer chew a little on what is needed to make 100 flywheel hp while I was having lunch. - In Missoula, on an average warm day, (85-90F.) And I see your point with wanting more displacement. It takes a rather stout set of stock valved heads and 9,5 Cr to make 100 hp with 1800 cc displacement.
With this in mind I would say don´t bother. Take the plunge, spend your money different and go at least thick wall 1835 or 1914 instead. Use a stock crank. Lighten the stock flywheel 2 lbs. and get the whole assembly balanced. Send the case out for machining. remember to get case savers installed (for 8mm studs) get Scat or CB cromemoly head studs and 9-1 CR. Then you´ll be at about 100 hp in your city.

T

[Bob Brugge]

Trying not to be an idiot. I drive like I know how, I don't launch it or fry tires. I just really want something that can do 75 or 80 all day with a little extra.
Here is my hang up with my 1800 cc proposal.
I already have most of the parts. I need internals, cam, crank, bearings and then I am off to build. I like the thought of having something different than everyone else.
So I can scratch the shorter rods, no big.
Lets talk a little about the considerations one must make when building a stroker, just in case I am missing stuff in my thought train.
Width is my biggest concern right now. I gotta get the valve covers off to adjust valves. Since it is a fight now, I don't want to have to fight it anymore. I have been seriously considering getting hyd lifters to stop the fight. I think I will have to have the lifter bores bushed so hyd lifters will fit. Not sure what that would cost tho.
I understand that with a longer throw crank, like a 74, there may have to be some clearencing. Rods and counterweights may come in contact with piston skirts. Shims may have to be added to get the right cr.
Pushrods may have to be cut or lengthened, I have a guy that can do that.
Did I miss anything? When I have assembled v-8's my biggest concern, with all of them, was getting the hood to close again. Clearly this isn't the issue on these vehicles, where the intake isn't going to cause the carb to sit higher.
What else am I missing?
_________________
Keep on Dubbin'!

[Pruneman99]

Lots of ways to make a stock width engine.

Stock everything
74 crank, a pistons, 5.325 rods
76-78 crank, b pistons, 5.5 rods. (Might have to cut barrels down for 76, small spacers for 78 )
82mm crank, b pistons, stock length rods

There are other ways depending on getting crazy with machine work, etc, but these get close. Heck, if you have a machinist on standby, pretty easy to o make a narrow engine. But same problems with going to wide fitting tins, exhaust, etc.

This has all been done before, no reason to try to reinvent the wheel. If you follow the 1800cc directions you will be fine. If you want to use parts that don't fit together without modifying everything just to have something different, you can do that too. Seems like smashing your head into a wall to cure a headache to me.

[vwracerdave]

[Bob Brugge]

[slalombuggy]

Bob,

Making the engine a bit wider is not that big of a deal. A bit of sheet metal trimming and everything will fit with a lot less effort and money that what you are trying to build. I just finished installing a 2332 I built in a friends 64. I had to trim the sides of the head tin and a bit of the body around the bumper brackets. The engine is almost 1/2" wider.

I'm currently building a 1904 (90.5A pistonsx74) and it's only 1/8" wider with 5.4 rods. That will fit easily inside the seals on my Ghia

I had over approx. 230hp in my street driven LSR car and a basically stock transaxle. Treat it with respect and it will live.

brad

[[email protected]]

there is less clearancing needed for 94mm pistons than 88mm, FWIW.
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[Max Welton]

Not everyone understands the being different impulse. I happen to because I are one.

But I'm not running a busy shop where a "different" engine for a customer would require that I rethink the combination the parts involved. I'm just a hobbyist who can afford to spend all my hobby time on one car. When I do want something different that involves machine work I need the help of a good machinist who is willing to work with me and I am prepared to compensate that machinist appropriately. The assembly and all the risk is mine..

If I were running a shop intended to make money I would stay with tried-and-true combinations that I could crank out one after the other without having to rethink anything. Time is money.

Btw, I can't imagine having time to be posting a lot on the Internet if I was running that busy shop. Maybe if I was retired from that. Dunno. Wouldn't want to do this for a living.

Max
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