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pig-pen
Samba Member
Joined: December 04, 2012
Posts: 570
Location: United Kingdom
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 Posted: Mon Dec 01, 2014 3:57 am Post subject: |
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Is that crank made form solid gold ?  |
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txoval
Samba Member
Joined: January 23, 2004
Posts: 3552
Location: The Woodlands, TX
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| Posted: Mon Dec 01, 2014 1:34 pm Post subject: |
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My vote is DPR...have Jose balance your crank, flywheel, and pressure plate at the same time.
HP cost $$$ |
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spencerfvee
Samba Member
Joined: August 19, 2004
Posts: 3071
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| Posted: Tue Dec 02, 2014 9:35 am Post subject: |
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Tell that to some formula vee guys that rev a 40 hp motor to over 6,000 rpm with a stock vw crank .theres a lot of fast 40 hp motors out there a lot of guys like old speed motors .any one can build a big motor .and go fast but not many guys can build a fast 40 hp motor .lol line boring a 40 hp case does not cost any more than line boring a1600 cc case .a 1600 crank will fit into a 40 hp case your machinist is not up to date on vws .he sounds like a nice guy he's just not up to date on vw motors spencerfvee
| jasengine wrote: |
I have just had a long conversation with a local engine machine shop who have advised me that it is not worth 'suping up' the little 40hp engine, especially with the 64mm crank! He when on to say that the 3 bearing crank in inherently week and adding counter weights to it will not really help with the strength at high revs, due to the boxer engine layout. Now something doesnt ring true here as CW cranks are common on the larger stokes for high performance applications.
I also asked about line boring of the case and he said this was a very costly operation, especially for this type of case!
Have I just been blinded by a lot of machinist talk or is there some truth in it? |
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earthquake
Samba Member
Joined: January 10, 2008
Posts: 3984
Location: SANDY VALLEY, NEVADA
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| Posted: Tue Dec 02, 2014 2:24 pm Post subject: |
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jasengine
Are you looking for a 36hp or 40hp crank? Have you checked into shipping to DPR, you might find some body that will supply a core to Jose if he does not have one. Do you have to pay VAT on labor?
Casey
_________________
74 CLASS 11 LOOK-A-LIKE
69 DUNE BUGGY
79 INTERNATIONAL SCOUT II
05 SCION XB SERIES RELEASE 2[#437]
95 Chevy C3500 dually
98 Ford E150
Link to Kelly J. Nolte 3/20/53 - 11/6/08
https://time-zonelabs.blogspot.com/p/about-kelly.html
DEATH TO CHINGERS!
[From a military recruitment poster in the novel "The Stainless Steel Rat" By Harry Harrison] |
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jasengine
Samba Member
Joined: June 07, 2012
Posts: 95
Location: Wales
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| Posted: Sun Jan 04, 2015 3:56 pm Post subject: |
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I didn't go with a counter balanced 64mm in the end; just had the whole assembly dynamically balanced. I couldn't justify the cost for counter weight version.
I will see how this one runs: the cranks are strong, as formula vee run theirs up to 7k rpm without breakage, but the cases take a beating! |
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spencerfvee
Samba Member
Joined: August 19, 2004
Posts: 3071
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| Posted: Wed Jan 07, 2015 6:35 am Post subject: |
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Hi here's my two cents when you put your crank in your case use two sets of steel back split bearing use the second set on the cranks cam gear end .this helps keep the crank from flexing at high RPMS .i have done this on all my motors .i like the way a stock crank revs .over a counter weighted crank .over the years I have built a lote of 40 hp motors and I have never had a crank break in two that was a 40 hp crank . My friend that worked at vw dealers ships in the 1960s told me when the 40 hp motors first came out that they did have cranks that did fail . My self i stay away from the early cranks .I try to use a 1964 or 1965 40 hp crank good luck with your 40 hp build . Spencerfvee
| jasengine wrote: |
I didn't go with a counter balanced 64mm in the end; just had the whole assembly dynamically balanced. I couldn't justify the cost for counter weight version.
I will see how this one runs: the cranks are strong, as formula vee run theirs up to 7k rpm without breakage, but the cases take a beating! |
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jasengine
Samba Member
Joined: June 07, 2012
Posts: 95
Location: Wales
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| Posted: Wed Jan 07, 2015 12:47 pm Post subject: |
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Thanks for the info. I have installed all Silverline bearings, not sure if these are steel backed! The crank is a 1970 unit, as is the case etc.. A late dual relief unit. The engine is almost complete now.
Edit: Yes Silverline bearing are steel backed!! |
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470robert
Samba Member
Joined: September 04, 2009
Posts: 2
Location: Wisbech. UK
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| Posted: Sun Feb 22, 2015 3:08 pm Post subject: 64mm Crank |
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| jasengine wrote: |
I didn't go with a counter balanced 64mm in the end; just had the whole assembly dynamically balanced. I couldn't justify the cost for counter weight version.
I will see how this one runs: the cranks are strong, as formula vee run theirs up to 7k rpm without breakage, but the cases take a beating! |
Formula V use a 69mm crank not the 64 1.2 one. I am going to build a 1200 using a stock crank, I through bolt and shuffle pin the centre main this gives the crank more support and reduces the chance of it breaking. You also need to seriously lighten the flywheel. Robert |
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henry roberts
Samba Member
Joined: February 24, 2003
Posts: 1275
Location: australia
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| Posted: Mon Feb 23, 2015 4:21 am Post subject: |
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| the formula vee rules vary from country to country. in australia the historic vees still run 1200's. the modern ones changed to a 1600 class with 4 lug wheels and 4 wheel disks 6-8-10??? years ago but they kept a 1200 class for people that didn't want to update thier cars... no idea if the class still exists, but you get the idea. |
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