gregrobbins
May 21 2005, 01:29 AM
QUOTE |
What is offered is a Type IV- 78 mm stroke performance crankshaft made from an original German VW forging, shot peened, stroked, counterweighted, machined, precision ground, and dynamically balanced. The main bearings are either .010 or .020 under standard and the rod journals are 50 mm diameter. If you are building a high performance engine for street or off road, where you want the incredible torque and power of a full counterweighted crankshaft, this is the crankshaft you have been waiting for. |
This crank is being offered by a shop that builds off road air cooled race motors. Would this work on a 2270? Or are you better off with a crank that has 55 mm rod journals and uses type I rods?
This crank is priced at $300 which seem reasonable.
skline
May 21 2005, 01:41 AM
I am not sure about the 55mm but I know you can get a DPR crank for about $375 or so new. Keep that in mind when you go to buy.
SLITS
May 21 2005, 01:42 AM
Greg...in order to get to the 78 mm stroke, they have to decrease the size of the rod journals as they are offset ground. 50 mm is what you wind up with.
You will need the matching rods and pistons. The rod length is different and the piston pin height is different from stock.
As I remember, the 78 mm stroker will fit into the case without clearance issues (no grinding on the case).
Bleyseng
May 21 2005, 07:27 AM
50mm is the 2.0L rod size so hmm, what is available in a 2.0L rod size. Nothing that I know of....Jake goes to a Type 1 rod cuz of all the different rods available and high quality rod bearings.
jasons
May 21 2005, 08:34 AM
I think Demello stroked my crank(insert Beavis and Butthead laugh here) for right around $300 maybe $350. If you have it done, you can get chevy or VW T-1 journals which offers the best rod selections. Incidentally, I didn't so I plan to use the 2.0 rods.
LouisCypher
May 21 2005, 08:35 AM
You can have the stock rods lightened by 200 grams, shotpeened and polished.
Louis
jasons
May 21 2005, 08:36 AM
QUOTE (SLITS @ May 20 2005, 11:42 PM) |
Greg...in order to get to the 78 mm stroke, they have to decrease the size of the rod journals as they are offset ground. 50 mm is what you wind up with.
|
They also weld the crank....
Jake Raby
May 21 2005, 09:59 AM
It has stock 2 liter rod journals..
Like mentioned above you only have 3 choices of rods with it
Stock 2 liters- They are too short for even the stock stroke crank, heavy as hell and generally suck for making a good combo. You can lighten them and do whatever you want and you are still stuck with a 650+ gram rod with a 24mm wrsit pin that limits the piston selections, especially those with higher pin heights.
Pauter- 800 bucks and still heavy
Carrillo- 1450 bucks.
The other issue is that the best bearing made for this journal is the std 2 liter VW bearing by Kolbenschmidt. These bearings suck for performance because they are only Bi Metal.
By using my crank or any other with a TI rod journal you are capable of creating a good rod ratio and the selection of rods is broad and a set of H beams is about 300 bucks instead of 1400!
Also we have Clevite Tri Metal rod bearings for the TI journal- these bearings are tough as nails compared to the 2 liter bearing. The piston selections are broad and much lighter with their 22mm pins Vs the 24mm pins
Doing this my way is cheaper, easier and creates a combo that not only is proven to work but also is correct mathmatically- its a much smarter way of doing things.
Type 4
May 21 2005, 10:02 AM
2.0 Rod Modded for 78mm Stroke.
Cunningham makes a 2.0 Rod for Strokers that Fat uses.
LouisCypher
May 21 2005, 10:35 AM
Stock rod weight = approx. 800 gr.
Lightening = approx. 200 gr.
Result = approx. 600 gr.
Joe Bob
May 21 2005, 10:43 AM
Been over 10 years....but I remember doing a stroker crank, Rabbit rods and Chevy pistons....great fun.
Verruckt
May 21 2005, 10:45 AM
Jake
What about the SB Chebby rods? Do they not give as good of rod ratio as the type 1 rods? Just wondering becuase I know there is an abundance of sb chebby rods available, with different lengths too, and they are fairly inexspensive.
Jake Raby
May 21 2005, 05:29 PM
Chevy rods are generally too wide on the big end and they are designed to run as pairs on the journal..
There are other rods that can be used, but all of them either cost more or create an engine that is more difficult to assemble.
The TI journal with an H Beam rod is very difficult to beat in price, simplicity to assemble and the powerband they create when matched to the correct cam...
I use the Cunningham rods in only one application, and thats my Powerstroke Bus engines.
Always remember that the selection that you make on one part, will effectively change the selection of every other part inside the engine that works in conjunction with it- just like a recipe for a cake....
Type 4 Unleashed
May 22 2005, 12:53 AM
QUOTE ("Z" @ May 21 2005, 08:43 AM) |
Been over 10 years....but I remember doing a stroker crank, Rabbit rods and Chevy pistons....great fun. |
Here, is a pic of a rabbit rod, bushed for a chevy .927 pin, the bolts have been turned around, and the bolts are 3/8 big block chevy ARP Wave loc Bolts, in it's present form, the rod weights 662 grams, it can be lightened at least 100g, the length is 5.355. These are going in my motor next week.
The other rod, is out of a Jetta or Gulf, it is 5.670" long, and the piston pin, is oiled from the rod bearing through the beam of the rod.
My current engine is 105.7 x 75, I was going to have my 75mm stroke crank, offset ground from 2.0 ltr journal size of 1.967 to rabbit journal size of 1.805, taking my 75mm stroke to 78.4mm, but I just got a line on a 80mm crank with rabbit journals, I may go that route instead.
Stroke and rod combinations are limited, only by the imagination
Mark Henry
May 22 2005, 06:18 AM
Jakes cranks and rods cost a couple of bucks more, but all the work is done. Why would you skimp on your bottom end?
Hey I build engines, I know some of Jakes basic crank/rod combos and I still get my crank/rods off of Jake.
Why piss around with unproven crap.
Type 4 Unleashed
May 22 2005, 11:55 AM
QUOTE (Mark Henry @ May 22 2005, 04:18 AM) |
Jakes cranks and rods cost a couple of bucks more, but all the work is done. Why would you skimp on your bottom end?
Hey I build engines, I know some of Jakes basic crank/rod combos and I still get my crank/rods off of Jake.
Why piss around with unproven crap. |
What skimping?
With the Rabbit Rod, I don't have to weaken the Cam by having it ground to a 1' Base Circle, for clearance for a stroker.
I, don't have to weaken the rod bolts, by clearancing for a stroker.
I, don't have weaken the case, by clearancing, for a stroker.
The Rabbit Rod, has a better Rod to Stroke Ratio, than the 2.0 ltr rod, and in stock form there 150g lighter each than the 2.0 Rod (1.34 pds total savings).
And as "Z" said this was done years ago, and this rod is still being used in Europe, in off road, there cheap, and plenty around.
The ouside dia. of the rods is directly proportional to the dia. of the rod journal.
A type 1 journal is about 2.160, chevy small jrl 2.00, 2.0 ltr 1.967 honda BMW 1.888 & 1.850, rabbit 1.805. with smaller outside dia of the rods, more clearance, and less clearancing you need in other areas, such as the cam, rods, and case.
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