78mm crank?

we carry 3 different 78mm cranks. The Flanged one is like $1400
(totally overpriced IMO), but we have a 4340 crank for $300, and a
precision welded crank for $450 (it specs out nuts on, that's why they
cost more).

http://www.aircooled.net/new-bin/viewproductdetail.php?keyword2=pos0004

I strongly suggest you stay away from the 4140 cranks.

John
Aircooled.Net Inc.
 >> Stay informed about: 78mm crank? 

"Joey Tribiani" <Joey.RemoveThis@yahoo.com> wrote in message
news:yDIjk.4811$LF2.3819@newsfe09.iad...
>
> "Anthony W" <technojock.RemoveThis@yahoo.com> wrote in message
> news:usyjk.317$aA5.98@trnddc05...
>> any recommendations on where to get a good 78mm crank. The one at
>> Aircooled.net is rather expensive and I'm not yet convinced that I need
>> to spend that much.
>>
>> Tony
>
> is your heart set on a 78?
>
> I hear good things about DPR welded cranks...
>
> john has the bugpack(4340 chromoly) for 300....
> CBPerformance has their super race crank(4340 chromoly) for 290
> CB has their 4140 chromoly in 76 and 74 for 180...
>

to add to my own response, i've read(I.E. no personal experience) that the
4340 cranks sold by Darren at DRD are really good cranks and a heck of a
deal.... 230 bucks
http://www.thesamba.com/vw/classifieds/detail.php?id=310738
 >> Stay informed about: 78mm crank? 

"AircooledJohn" <john.TakeThisOut@aircooled.net> wrote in message
news:a45329cc-d189-40a5-ba3c-b300fb4d4138@b1g2000hsg.googlegroups.com...

>
> I strongly suggest you stay away from the 4140 cranks.
>
> John
> Aircooled.Net Inc.

John...good to hear from you... never heard too much about the 4140's
longevity or performance... can you give us some insight? there were folks
on other forums that bought them and promised reports back about quality of
machinework, performance, etc... never heard back...

good information from someone with the knowledge of parts and your
experience would be great for all of us...
[/asskissing] <G>
 >> Stay informed about: 78mm crank? 

Joey Tribiani wrote:
> is your heart set on a 78?
>
> I hear good things about DPR welded cranks...
>
> john has the bugpack(4340 chromoly) for 300....
> CBPerformance has their super race crank(4340 chromoly) for 290
> CB has their 4140 chromoly in 76 and 74 for 180...

78 mm is as far as I can go without too much bottom end work or I would
go 80mm. I'll have to check again but the forged cranks I saw on John's
site were all around $600. I would like to explore all my options
before spending that much...

Tony
 >> Stay informed about: 78mm crank? 

"Anthony W" <technojock.TakeThisOut@yahoo.com> wrote in message
news:BZMjk.356$wS4.307@trnddc03...
> Joey Tribiani wrote:
>> is your heart set on a 78?
>>
>> I hear good things about DPR welded cranks...
>>
>> john has the bugpack(4340 chromoly) for 300....
>> CBPerformance has their super race crank(4340 chromoly) for 290
>> CB has their 4140 chromoly in 76 and 74 for 180...
>
> 78 mm is as far as I can go without too much bottom end work or I would go
> 80mm. I'll have to check again but the forged cranks I saw on John's site
> were all around $600. I would like to explore all my options before
> spending that much...
>
> Tony
>

bugpack 4340:
http://aircooled.net/new-bin/viewproductdetail.php?keyword2=ECR0006&ca...d=07292
 >> Stay informed about: 78mm crank? 

AircooledJohn wrote:
> we carry 3 different 78mm cranks. The Flanged one is like $1400
> (totally overpriced IMO), but we have a 4340 crank for $300, and a
> precision welded crank for $450 (it specs out nuts on, that's why they
> cost more).
>
> http://www.aircooled.net/new-bin/viewproductdetail.php?keyword2=pos0004
>
> I strongly suggest you stay away from the 4140 cranks.
>
> John
> Aircooled.Net Inc.

Thanks John, I must have missed the welded crank when I was looking over
your site last night. So far this sounds like my best option. I'm
building a low RPM high torque engine and I should be able to get away
with stock con-rods.

I was also looking at that torquer Web cams you carry, do they produce
more torque than a stock cam?

BTW, it's good to see you posting again. Take care.

Tony
 >> Stay informed about: 78mm crank? 

my recommendation is a 82mm 4340 crank with 5.4" H-beam rods. It's
easier to build than a 78 IMO.

John
Aircooled.Net Inc.
 >> Stay informed about: 78mm crank? 

How so? Wouldn't the case have to be releived more for the extra 4mm of
stroke?

BTW, when you posted the link to the welded type one crank on your site
I was able to see it but I can't seem to browse to it from your home
page. Any idea what am I doing wrong?

Tony

AircooledJohn wrote:
> my recommendation is a 82mm 4340 crank with 5.4" H-beam rods. It's
> easier to build than a 78 IMO.
>
> John
> Aircooled.Net Inc.
 >> Stay informed about: 78mm crank? 

yes you have a touch more clearancing, BUT pistons are setup for 82mm
strokes, so while you have less clearancing, with 78mm strokes you
have another problem which is excessive deck height. That solution is
to shorten the cylinders. I find it much easier to get the case
clearanced by a place like RIMCO and you simply deburr and clean, then
you do not have the headache with the piston being in the wrong place.
The 82mm is an easier build than a 76 or 78 IMO. When guys are
building 76 or 78 it's almost always because they are afraid of the
clearancing work, and it's not a big deal, really.

John
Aircooled.Net Inc.
 >> Stay informed about: 78mm crank? 

I think building a stroker 85.5 is a complete waste of time and money,
and have stated this for years. You should increase the bore size, and
if you have $ leftover in your budgeting get an 82mm crank and 5.4" H-
beam rods.

John
Aircooled.Net Inc.
 >> Stay informed about: 78mm crank? 

AircooledJohn wrote:
> yes you have a touch more clearancing, BUT pistons are setup for 82mm
> strokes, so while you have less clearancing, with 78mm strokes you
> have another problem which is excessive deck height. That solution is
> to shorten the cylinders. I find it much easier to get the case
> clearanced by a place like RIMCO and you simply deburr and clean, then
> you do not have the headache with the piston being in the wrong place.
> The 82mm is an easier build than a 76 or 78 IMO. When guys are
> building 76 or 78 it's almost always because they are afraid of the
> clearancing work, and it's not a big deal, really.
>
> John
> Aircooled.Net Inc.

Are you referring to the 85.5mm stroker piston and cylinder set or the
stock cylinder set? I was thinking about using stock cylinders with
spacers with the 78mm crank. One advantage of more stroke would be that
I could possibly have more low end torque and that would be good.

Would the Webcam torquer cam give more low end power than a stock cam?

Ton
 >> Stay informed about: 78mm crank? 

AircooledJohn wrote:
> yes you have a touch more clearancing, BUT pistons are setup for 82mm
> strokes, so while you have less clearancing, with 78mm strokes you
> have another problem which is excessive deck height. That solution is
> to shorten the cylinders. I find it much easier to get the case
> clearanced by a place like RIMCO and you simply deburr and clean, then
> you do not have the headache with the piston being in the wrong place.
> The 82mm is an easier build than a 76 or 78 IMO. When guys are
> building 76 or 78 it's almost always because they are afraid of the
> clearancing work, and it's not a big deal, really.
>
> John
> Aircooled.Net Inc.


I built a 78x90.5 with B pistons, and 5.5" rods. Everything came
somewhat close to where I wanted it with minimal shimming, I can't
remember if I used any shims. I may have shortened the cylinders, and
around the same time I shaved some material off of piston tops too but
it could have been a different engine... LOL.
The longer than stock rods should help it run stronger at higher rpms.
Redline is around 8000.
 >> Stay informed about: 78mm crank? 

Jan Andersson wrote:
> I built a 78x90.5 with B pistons, and 5.5" rods. Everything came
> somewhat close to where I wanted it with minimal shimming, I can't
> remember if I used any shims. I may have shortened the cylinders, and
> around the same time I shaved some material off of piston tops too but
> it could have been a different engine... LOL.
> The longer than stock rods should help it run stronger at higher rpms.
> Redline is around 8000.

I'm building a low RPM torquer and I neither need nor want the engine to
rev over 4k RPM. OK, I'll fess up, this is for an airboat and it will
be running it flat out most of the time. Peak HP is of little use to
me, I'm looking for maintainable low RPM power to drive a prop.

The 82mm crank sounds interesting if I can use it with stock cylinders...

Tony
 >> Stay informed about: 78mm crank?