69mm crankshaft quality: old SCAT vs. DPR.

[jimmyhoffa]

I am building two engines side by side for similar purposes: off road buggy. I have two cranks:

~1980 SCAT forged counterweighted, STD mains and .020 on the rod journals. This was BEFORE the groove around the mains for oiling. Main oiling holes are scalloped similar to later beetle crank.

-A recent DPR welded counterweighted, .010 on mains and .010 on rods.

One will be my lower-tune spare/daily engine, a 1835cc with rebuilt rods and stockish heads fed by a single 40 IDF on a CB intake. WEB 119.

The other will be my 1915 with full FAT intake and better heads fed by a single 44IDF. Web 218/119, I-Beams with 3/8 ARPs, CB rocker with elephant feet.

Which crank goes in which engine? Reasons? I can't decide because I don't know if either has any benefit for a given situation.
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1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[vwracerdave]

Flip a coin, it probably doesn't matter for either engine. If I hade to choose I'd put the DPR crank in the 1915.

What cases do you have and what align bore? bearing thickness might be a deciding factor.
_________________
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
Featured in Dec. 2001 HOT VW's Magazine page 63

Watch my racing video's http://www.youtube.com/user/okvwracer/videos

[jimmyhoffa]

Ooh thanks and good question!

Both cases are at .020 over line bore and one has a light thrust cut. Of course my AK case that was so young it still has a tight stock thrust is going to be the basis for my 1915.
_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[esde]

let the rods decide; if one set fits one of the cranks better than the other, there you have it. Should not be a difference, but there often is, even if it's just side clearance.
If there is no difference, flip a coin.
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modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that.

[jimmyhoffa]

I like it! That's one of those things I would have realized when I was putting them together but not now, so your advice gives me the chance to be smarter about rod bearing purchases.

I take it the old SCATs from the 80s are actually all-american? Of course their modern cast cranks are import and I'm assuming their mid-grade forgings are as well.
_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[mark tucker]

i wood go with scat every time if the cost is the same. if a welded crank is half the price it may be worth taking a chance if thats what you want to do. Ive had 3 welded cranks in my shop...all 3 were not right from the maker.... runout on the crank gear journal,weld filled oil galley holes and taper on the thrust surface...

[nsracing]

The old Scat cranks were forged one-piece and were very good! I used several full flanged ones and they held up to full drags.

The DPR with welded CW is fine for what you want. But the Scat is special if it is early 80's. I have 2-3 forged strokers from Scat still in cosmoline from way back.

I will use the DPR and save the Scat.

[jimmyhoffa]

Haha well, I'll probably put the SCAT in my "spicy engine" then here is the SCAT. My DPR actually checks out great too.

_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[nsracing]

Sorry to tell you... but that may be one of the Volkstroke cast cranks Scat came out before in their kits.

The Scat forged cranks were white almost in appearance. And they will 'ring' when you hit it just like any forged crank.

Also, Scat forged cranks had smaller counterweight profiles than what you got there.

That crank may be cast - someone correct me if I am mistaken.

By the way, Scat forged cranks were around $600 each back in the 80's.

[Dan Ruddock]

Use the DPR.

[jimmyhoffa]

So, the above crank is the likely even worse 80's equivalent of this:

https://vwparts.aircooled.net/SCAT-Volkstroker-III-Counterweighted-Crankshaft-p/10692.htm

That kinda sucks.
_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[Danwvw]

I have one of those early Scat cranks, It's a 74mm and after I got the engine all together I discovered the pulley moves up and down 20 thousandths every revolution it's been balanced and everything not sure I should keep it with the engine or not. Seems to run just fine and smooth and all.

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1960 Beetle And 1679cc DP W-100 & Dual Zeniths!

[esde]

[Danwvw]

It's the crank!
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1960 Beetle And 1679cc DP W-100 & Dual Zeniths!

[nsracing]

Or could be the pulley— are u sure the pulley snout is not bottomed out?

[Danwvw]

It's the crank, as I tried several pulleys, I can see it. The end seems to rotate at a little bit of an angle almost like it was bent. Pretty sure the rest of the crank is fine just the end is wacky.
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1960 Beetle And 1679cc DP W-100 & Dual Zeniths!

[jimmyhoffa]

Egh. Bummer for both of us. If yours is forged mine definitely is not. Also I guess yours is trash, maybe straighten the end and then have it reground to true it up?
_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[vwracerdave]

Your SCAT cast crank will be fine for your 1835cc street engine. My 1835cc with a cast crank has over 600 1/4 mile passes and many years of street driving.
_________________
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
Featured in Dec. 2001 HOT VW's Magazine page 63

Watch my racing video's http://www.youtube.com/user/okvwracer/videos

[jimmyhoffa]

Yeah buuuuutt... If something does happen then it's all over... I think I need to call Jose and get another DPR.
_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.

[jimmyhoffa]

Here's some better pics. In good shape, checks out dimensionally, straight when indicated and spun on #1 and #3 bearings in a case half, but I believe it's cast.

_________________
1974 Chenowth 2RL #1244 Street Legal
My other car isn't ridiculous.