Subject: Curiosity regarding capacity vs cases vs cranks...
benny_acko
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posted on June 23rd, 2015 at 07:58 PM
Curiosity regarding capacity vs cases vs cranks...
Hi all,
Please excuse my ignorance.
I am trying to do some research around having a larger than stock engine built down the track.
However I was wondering:
- could you use a case that has been clearanced for a larger crank (eg 82mm) but still run a 69mm? I admit I am still trying to work out what size
capacity but was wondering if you could buy a case that has been clearanced and machined already, run a 1915 and then if I wanted to go larger down
the track it would be already done. My thinking is that a stroked motor may not have to not work as hard and potential for more torque.
- what impact does deck height have on building an engine? When looking online at cases there are multiple options available.
Apart from a budget, is capacity the first variable to be figured out?
I understand that people like Rod Penrose and others sell packaged motors with this all figured out however I would like to develop my knowledge a
little also and potentially look at buying parts separately over time.
If anyone can point me in the direction of some reading or previous threads that may assist that would be appreciated.
Many thanks,
Ben
1967 VW Beetle Deluxe
fish26
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posted on June 23rd, 2015 at 09:11 PM
Yes
I like close to zero deck 0.060" is the norm you can achieve this by shims and/or machining, you can order a case with correct deck once you've
calculated the combination.
No, car weight and driving purpose will determine engine configuration
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posted on June 23rd, 2015 at 10:24 PM
Benito's advice is good. Read, read, watch then read more.
The books suggested are excellent, there are other titles by Keith seume that are also ok for reference. There are also some good dedicated vw
channels on YouTube. Look for " vwDarren" and also "theEzGz" (as in eeezeegeezee). Both American guys with funny accents but helpful videos.
Don't get me wrong - I am no gun mechanic, or vw guru. I am possibly a year in front of you as this time last year , got itchy to learn about vw
engines... Now I'm up to my eyeballs. Reading all the books again, still thinking, planning and learning heaps.
Good luck with it.
hus22l
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posted on June 24th, 2015 at 07:25 AM
..If your going to buy a new case, might as well buy a clearanced one. I don't see any issue with it. Then, if you have a clearanced case... Might
as well put a stroker crank in it. All comes back to what you want. You won't need a clearanced case for smaller size stroker cranks.
Deck height will depend on the combo of crank, rods, pistons and cylinders ..and heads, it's calculated as part of the way to measure and set your
compression ratio. Depending on where you want that will guide you as to what deck you will require. Tricky to explain, but I hope that helps.
Maybe start with an engine size you think you might ultimately want, then look up existing build combinations. See what parts they used and how they
went together.
benny_acko
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posted on June 25th, 2015 at 01:43 PM
Thanks for the responses and I will look at getting copies of the books.
Cheers
