Building a Stroker, what should I build?

[sactojesse]

[Ghia72]

I read something about that, what material is being removed? making the hole larger for the cylinder to sit? taking material out so the cylinder can sit deeper? I'm not familiar with this process. In your opinion, is this less desirable then having the cylinders bored out leaving less wall material?

[sactojesse]

Not my picture, just something I found in the gallery here, but you can see, with a case cut for 94 mm/92 mm thickwalls, how close the case savers for the studs are getting to the bore where the cylinders are inserted into the case:

Stock 85.5 mm and slip-in 87 mm pistons and cylinders require a 90 mm opening in the case. 90.5 mm and thinwall 92 mm cylinders require a 96 mm case opening. 94 mm and thickwall 92 mm cylinders require a 97.25 mm opening. That said, there's not much difference on the case end between 94/92 thickwalls and 90.5/92 thinwalls. The real difference is at the head end, where 94/92 thickwalls require a 3.1 mm larger cut.
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1966 Karmann-Ghia convertible

[vwracerdave]

If I were building an engine that was expected to go 100,000 miles or more I would not use anything larger then 90.5mm pistons. The larger pistons will run hotter and they will not last as long. DO NOT get sucked into the 'bigger is better' crowd or the Internet crew chiefs that say '94's cost the same as 90.5's so why not go bigger'. You will not notice of feel a HP difference between a 78X90.5=2007 and a 78X92=2074. Just remember bigger gets less fuel mileage and with a 60 mile daily commute that can start adding up quickly.

Take a few days and read all the technical material from www.geneberg.com
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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

[Ghia72]

this has a lot of good info, I had no idea those lower priced gauges where so far off (almost bought some). So lets say I do go with the 2007, living in an area with hills and temps up to 120 in the summer, should the .148" = 90.5mm compared to .163" = 85.5mm stock not be a heat concern?

GBSKIT-1-78 -- 2006CC
http://www.geneberg.com/cat.php?name=Engine%20Kit%20Deals&cPath=551

is this a 2007???

Still reading tech info, thanks!

[c21darrel]

I agree w/ racerdave and sactojesse...2007...
Another great source of quick learning are the tech articles john at aircooled.net. wrote. Breaks everything down starting at square one. Teaches you about how to budget, what to do first, how to plan your build, how as you change one engine part what other parts are affected.
Good luck.

[Ghia72]

I've actually gone through that site a few times for information, good site. any answers on the questions i sent in before? I'm almost sold on the 2007 just making sure its not going to be more prone to overheating then my stock 1600 because of the thinner cylinder walls.

[vwracerdave]

I can assure you there are thousands and thousands of people that have gotten 100,000 miles out of 1776, 2007, and 2110 engines with 90.5mm pistons the last 40 years. The 90.5's have proven to be just as durable as the 85.5's Keep your compression ratio moderate around 8 to 8.5 and you will not have overheating problems.
_________________
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

[DET]

Hi all, I am a newbie here. Great information here. Please excuse me if I hijack the thread. But could someone comment on what rod lengths are good for 74 x 90.5 and 78 x 90.5 and what type (A or B) piston for each (Mahle)? for each? Thanks.

[Ian Godfrey]

I would suggest VW length with either cylinder. Or in an aftermarket rod say 5.4 or 5.5"
with a 78 stroke use B pistons, goes together fairly easily, but the case needs more work
74 is trickier, you could use A pistons and spacers under the cylinders, or B pistons 5.5 rods and shorten the cylinder length. either way there is more work making cylinder tin fit and getting push rods the right length.
I suggest either counterweighted/balanced 69 crank and A pistons or
78 crank and B pistons.
either way you will need to build and measure it to add cylinder shims or flycut heads to get the compression you need.
have a look at the CB kits which take a lot of the guesswork out
https://www.cbperformance.com/Builder-s-Choice-Engine-Kits-s/116.htm

[DET]

@Ian Godfrey ... Thank you for the feedback. It's greatly appreciated.