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Sat Mar 26, 2011 6:14 am

So after my recent engine issues i went out and bought a replacement crankcase to build another engine. Its an AS41 mexico / brazilian case so its dual oil relief.
Whats the biggest engine i can build without having to machine the case?
I have tried reading about strokers but cant work out if these just use another crank or whether they use different Barrels and pistons or can i just use standard equipment?
I have also read that the case needs clearancing to take the crank can this be done at home or is this a machine shop job?
Is everything else standard, heads / cams etc?
What carb / carbs can i run?

Sorry for all the questions but building a stroker is new to me

Sat Mar 26, 2011 6:55 am

If you use rods that are clearanced for a stroker motor you might get a 76mm crank in there without having to clearance the case, but you will probably have to do alittle grinding.
If you try to use stock rods you will have to clearance quite a bit.

Sat Mar 26, 2011 7:14 am

Do a lot of home work. Are you doing it or an engine builder?
76mm balanced crank. Keep it simple.

Sat Mar 26, 2011 11:43 pm

worton75 wrote: Whats the biggest engine i can build without having to machine the case?
1849cc. Use 88's with the barrel bases turned down and a 76mm stroker crank. http://www.thesamba.com/vw/classifieds/detail.php?id=806472

worton75 wrote: I have tried reading about strokers but cant work out if these just use another crank or whether they use different Barrels and pistons or can i just use standard equipment?
Any crank larger than the stock 69mm is considered a stroker crank/engine. 69, 74 and 76mm cranks use "A" pistons. 78mm and larger use "B" pistons. There are exceptions but keep it simple for now. Stroker cranks can be a reworked (stroked and counterweighted) stock German crank or a brand new crank (the vast majority are from China) that is forged to the stroke with counterweights built in.

worton75 wrote: I have also read that the case needs clearancing to take the crank can this be done at home or is this a machine shop job?
With a 76mm crank and aftermarket I or H beam rods clearancing really depends on the case you have. Some require light hand clearancing, some require no clearancing. A 76mm crank and stock VW rods would require a lot of clearancing, probably similar to what you would normally do with 78mm and larger strokes. It's worth it to have this type of clearancing done at a good VW machine shop as they have all the fixtures/cutters/machines needed to do it right plus it makes a hell of a mess cutting out all that metal.

worton75 wrote: Is everything else standard, heads / cams etc?
What carb / carbs can i run?
You'll need to get the heads cut for barrels 88mm and larger. Headwork is always a plus as better airflow can lead to better power, performance and even gas mileage depending on application. Carbs/heads/exhaust and cam should be considered as a complete system and will depend on what you want to accomplish with the motor. You can't change one part without affecting the way the others work and it's not economically wise to buy what you can now and upgrade later - just save up till you can build the best motor you can afford.

Sun Mar 27, 2011 5:19 am

I built my 1850cc in 1988 and still run it today. I did have to notch the cylinder holes in the case a little to clear the rod bolts.
76mm bugpack crank 12lb flywheel
88mm cima piston/cylinders
Scat I beam rods stock length
041 heads ported my self
FK 8 Engle (Iknow, too much cam)
36mm Delloratos
009 w/points
! 5/8 merged header w/single chamber Flowmaster
It ran 15.16 (9.51 1/8)in my full body/interior 65 bug on street tires and stock trans and stock clutch and pressure plate.
I drive it daily unless the weather is nasty for 20= years.
Tim

Sun Mar 27, 2011 5:44 am

Wow rgdedge, thats awsome!! I will be happy if the stroker I am building lasts half as long as that?? 8) 8)

Sun Mar 27, 2011 7:58 am

The costs associated with building a stroker motor of 76mm vs 82mm isn't all that much compared to what you get in return. If a competent machine shop clearances your case (have them open the cylinder spigots for 90.5/92 or 94mm while their at it) assembly procedures are very similar for the 'no-machine' stroker you are considering. The benefits of having those extra 3-500ccs are very apparent in the seat-of-the-pants when you are done and will put a smile on your face. Machining is a few hundred more - the cranks and pistons/cylinders will cost very close to the same - be it 85.5x74mm or 90.5/92x84mm. You will still have to figure out which barrel spacers to use - set valve train geometry etc - same as in the 82-84mm stroker. Even for a stock motor these things need to be done to ensure a reliable motor.

May as well step up and go big if you want a stroker - you'll spend a lot of time second guessing your 85.5x76mm build vs what could have been. Forget the 87 & 88 no machine piston & cylinder 'slip-in' sets unless you like replacing them on a regular basis. I've used them with mixed results - but I've used stock 85.5 and had very good results nearly every time. Sealing at the head is especially bad with those thin wall cylinders even using a copper gasket.

I'm sure there are a dozen guys that can step up and tell you how great those 87s have been for them - but there are hundreds more that will tell you why you shouldn't use them. What they give you in increased displacement is lost in so many other areas - sure - they run great - for about 20-30k.

Sun Mar 27, 2011 9:02 am

Cheers guys, looks like i need to do some reading and work out exactly what i want out of the engine (which is for my 69 Bay so just want something reliable that will pull a fully laden bus along without me having to get out and push on hills :lol: )

Sun Mar 27, 2011 9:27 am

Check out Krusher's build and dyno sheet for his 88 x 74 Bus motor, he seems very happy with his combo:

http://www.thesamba.com/vw/forum/viewtopic.php?t=447590&postdays=0&postorder=asc&start=0

Sun Mar 27, 2011 9:29 am

Love that TQ curve!
Just can't beat a stroker motor for the street! 8)

Mon Mar 28, 2011 6:17 am

Wow that's one bad little motor.

Mon Mar 28, 2011 6:20 am

Think i'm going to stay at standard stroke as the machining costs on top of the other parts needed doesn't make this an economically viable at the moment, maybe at sometime in the future i will re-think but for now it stock stroke :(

Mon Mar 28, 2011 6:55 am

I would recommend building a 1915 to anybody that is building a performance vw on any kind of budget..

if money is no object then stroke away!!! stroking your engine opens a can of worms that has all sorts of costs and head aches associated with it..

boring your engine opens a considerably smaller can of worms! the money you save on machining and clearenced rods, you can spend on a nice set of heads..

before all you strokers have a stroke, i'm not suggesting against stroking engines! I'm just saying that on a budget, one can save money on parts by keeping with the 69mm stroke (may as well have it counterbalanced) and using 94mm A pistons, and use the money towards real nice ported and bigger valve heads..

that is how I would do it if I had it to do over again.. I ended up with a 2110 (95cc bigger than 1915) and no money left over for real nice heads. next engine will either be built with no budget or a nice simple 1915 with the nicest heads i can find..

Mon Mar 28, 2011 9:31 am

cptcliffhanger wrote: I would recommend building a 1915 to anybody that is building a performance vw on any kind of budget..

if money is no object then stroke away!!! stroking your engine opens a can of worms that has all sorts of costs and head aches associated with it..

boring your engine opens a considerably smaller can of worms! the money you save on machining and clearenced rods, you can spend on a nice set of heads..

before all you strokers have a stroke, i'm not suggesting against stroking engines! I'm just saying that on a budget, one can save money on parts by keeping with the 69mm stroke (may as well have it counterbalanced) and using 94mm A pistons, and use the money towards real nice ported and bigger valve heads..

that is how I would do it if I had it to do over again.. I ended up with a 2110 (95cc bigger than 1915) and no money left over for real nice heads. next engine will either be built with no budget or a nice simple 1915 with the nicest heads i can find..

Your suggestion of keeping with the stock stroke - then suggesting a CW crank - flies in the face of reason. Since a 69mm CW crank is going to cost very close to the same as a 74 or 76mm stroker anyway I say go with the stroker. A set of I beam rods aren't that expensive and they usually fit with no problems. Cylinder shims and cut to fit pushrods are something you need for a 1915 anyway. I certainly wouldn't bolt up all the parts from the parts bin and call it neat.

1915 may be only 195cc away from a 2110 but the 2110 has more torque - everything else being equal. And the 2110 will last longer and very likely cost less to rebuild. 1915s are hard on cases. Costs associated with 'doing it right' are very close to the same regardless of size until you get into 86mm and larger strokes.

Just MHO.

Mon Mar 28, 2011 9:50 am

Worton, take some time to think about it. Even a 74mm stroke will make a dramatic improvement in torque and drivability over a stock crank. With larger P/C's it's even more pronounced. A 74 crank with, for instance, CB Uni-Tech HD Plus rods will probably drop in most cases or, at most, need light hand clearancing that you could easily handle.

Thu Mar 31, 2011 2:04 pm

Have been in contact with some machining companies here in the UK and i'm looking at about £125 to open the case up for 90.5mm barrels and about the same again for the heads and About £50 for having the case drilled for an external oil filter.
So thats £300 just for the machining alone (is this a good price?)
90.5mm Barrels and pistons brand new cost about £280
So looking at close to £600 for 1776cc build , if i then decide to stroke it a CW crank is another £300 minimum, add on a few odds and sods (push rods and tubes, spacers, new oil pump etc) and your probably talking close to £1500 for a home built stroker :shock:

Might be able to get away with the 1776 items but dont think i will convince the wife about finding another £1000 + on top of this :oops:

Thu Mar 31, 2011 2:23 pm

Go ahead and add an additional 30% to 40% to your numbers.....it is always more than you think it is going to be....no matter how much you plan ahead.

Thu Mar 31, 2011 2:32 pm

scottvw wrote: Go ahead and add an additional 30% to 40% to your numbers.....it is always more than you think it is going to be....no matter how much you plan ahead.
Yeah i know thats the scary thing, what was meant to be a cheap homebuild could soon become a very expensive home build, and it seems that here in the UK we are paying a lot more for our performance parts than over in the US.

Sat Apr 02, 2011 1:47 pm

DarthWeber wrote: Worton, take some time to think about it. Even a 74mm stroke will make a dramatic improvement in torque and drivability over a stock crank. With larger P/C's it's even more pronounced. A 74 crank with, for instance, CB Uni-Tech HD Plus rods will probably drop in most cases or, at most, need light hand clearancing that you could easily handle.
How would this compare to either a stock set up (1584) or a 1776?
A counterweighted crank works out cheaper than the machining of a case so if i was to use say a 74mm stroker with 85.5 C&B's what would this give me compared to the above?

Wed Jun 22, 2011 6:21 pm

If you look at the build & Dyno sheet above for the 88 x 74.

It looks like you could try any of the slip-ins & have a pretty peppy motor.

That's probably the route I'd take with my low budget build.