| View previous topic :: View next topic |
| Author |
Message |
neil68
Samba Member
Joined: March 17, 2007
Posts: 2228
|
 Posted: Mon Apr 30, 2012 4:38 pm Post subject: Re: engine build on an as21 |
 |
|
| Schatzi wrote: | First time long time. I've used these forums many times for reference, and I guess it's my turn now.
I'm finally getting around to building my engine. I'm going from the ground up, and my build style is going to be to try to balance the living piss out of this thing and try to eek as much mileage as I possibly can.
-The Problem-
My case to build with is a fuelie case ca. late '79 that's been stroked to almost 76mm (with small rods) and bored for 94mm
So, AS21, had 3 out of round lifter bores. bored and sleeved all 8 to repair. Line bore is now 20 over.
I want to build this motor to last my penchant for twisty back roads. I'm not a drag strip launcher, but I do intend to buy lots of quality guts in the hopes that by building with good gear and taking the time to balance and blueprint frigging everything, I'll be able to make good mileage on this old case and still have fun tearing up Hwy 112 in the summer and daily driving the rest of the year.
Am I wasting my time? Is a line-bored as21 with repaired lifter bores capable of providing a second go-round of use, given a quality build?
INPUT?! |
This thread seems to have been side-tracked.
Getting back on track: I would recommend that you check the case and then if in doubt get a reputable machine shop to check/sleeve the lifter bores. There's nothing wrong with an AS21 '79 Type 1 case, as long as it hasn't been abused too much. There are many reputable crankshaft suppliers as noted: CB, Bugpack, Scat, DPR, etc. You're better off asking some local Type 1 suppliers/builders to assist, or go straight to the suppliers...just make sure that they will work with you if there's an issue.
FWIW, I've used CB 78.4 mm crank in the past, and it spec'd perfectly (also using their 84 mm now, also perfect...just needed balancing). Check the engine combo sticky above as well, for more details. I'm not a fan of 76 mm cranks...might as well go to the 78.4 mm, but that's your decision.
Good luck!
_________________
Neil.
"Real men run drums."
Der Kleiner Rennwagens
68 Beetle 2332 cc
12.8 seconds @ 104 mph
http://www.youtube.com/watch?v=FF2gCti3dro |
|
| Back to top |
|
 |
Schatzi
Samba Member
Joined: April 29, 2012
Posts: 12
Location: Seattle, WA
|
| Posted: Mon Apr 30, 2012 6:39 pm Post subject: Re: engine build on an as21 |
|
|
| neil68 wrote: |
I would recommend that you check the case and then if in doubt get a reputable machine shop to check/sleeve the lifter bores. |
Already did. Like I stated in the first post.
| neil68 wrote: |
I'm not a fan of 76 mm cranks...might as well go to the 78.4 mm, but that's your decision. |
The case was already clearanced for 76mm with a small rod like a chevy rod, or a really expensive VW rod like a Carillo. Or I could run a 74mm crank with any rod.
As far as the chevy journal cranks, mightymouse, could you explain why they suck?
Also, I may be wrong on the flycut, maybe it was a hundredth that got shaved off the spigot holes and #1 main thrust area. |
|
| Back to top |
|
|
mark tucker
Samba Member
Joined: April 08, 2009
Posts: 8509
Location: SHALIMAR ,FLORIDA
|
| Posted: Mon Apr 30, 2012 8:28 pm Post subject: |
|
|
| I kinda like the honda journel it's even smaller for more stroke.if your breaking cranks you need to find the issue,not blaim it on the chevy size.the bearing & crank dont know what size they are, nor do they care that chevy uses the same size or did in the past. |
|
| Back to top |
|
|
modok
Samba Member
Joined: October 30, 2009
Posts: 8628
Location: Colorado Springs
|
| Posted: Mon Apr 30, 2012 8:34 pm Post subject: |
|
|
Try the crank and see if it fits, it may or may not
I've had 78 stroke and 2" journal eagle rods fit with no work done at all.
If you had 2" journals and carillo or eagle rods you could fit WAY more stroke than 76 
if you see that the case is clearanced somewhat then it may fit 74 stroke with stock clearanced rods, or 78 with aftermarket rods that use bolts but no nuts. The aftermarket rods fit better because the bolts are more compact and the caps are thinner. |
|
| Back to top |
|
|
Schatzi
Samba Member
Joined: April 29, 2012
Posts: 12
Location: Seattle, WA
|
| Posted: Wed May 02, 2012 2:56 pm Post subject: |
|
|
whatever rods I go with needs to be ARP-bolted.
So, you guys think the GSC ebay-special cranks are not as good?
new chinese 4340 forging? < reground/wleded unit from machine shop? |
|
| Back to top |
|
|
homebrew_86
Samba Member
Joined: October 16, 2011
Posts: 4
Location: Seatlle, WA
|
| Posted: Wed May 02, 2012 4:19 pm Post subject: |
|
|
Go into NW Con-Rod and talk to Jerry about all this stuff. He will sit down and build your whole engine on paper if you want and answer all your questions as you go. I just gave him my plan and my budget and he pointed me in the right direction. I'm in the middle of my first build so he's been a huge help to me. Also lurking about in these forums doesn't hurt.
Cheers |
|
| Back to top |
|
|
Schatzi
Samba Member
Joined: April 29, 2012
Posts: 12
Location: Seattle, WA
|
| Posted: Wed May 02, 2012 10:11 pm Post subject: |
|
|
thanks homebrew! Ya, I think I'm gonna go with the ebay special. It's a newly forged nitrided jobbie, so I think that'll work well, especially after a through balancing.
So I guess the general concensus is that this as21, despite a line bore, sleeved lifters, and flycut spigots and #1, is still going to provide me with 100,000+ miles of spirited daily driver type driving, provided I balanced the shit out of everything? |
|
| Back to top |
|
|
modok
Samba Member
Joined: October 30, 2009
Posts: 8628
Location: Colorado Springs
|
| Posted: Thu May 03, 2012 9:44 pm Post subject: |
|
|
Like I said earlier, the best gauge of how beat the case is is to measure how warped it is, and your guy gave it the ok, so it probably is fine. It does not matter how old it is or what it looks like or anything, if the round parts are still round and the flat parts are still flat then it is still young 
It is unlikely that an e-bay crank would be any cheaper or better than any other. If you wish to roll the dice and buy a china crank from a discount house then why not go to the source? AA......... revmaster.......... century distributors.........ect |
|
| Back to top |
|
|
homebrew_86
Samba Member
Joined: October 16, 2011
Posts: 4
Location: Seatlle, WA
|
| Posted: Fri May 04, 2012 6:48 pm Post subject: |
|
|
| Schatzi wrote: | thanks homebrew! Ya, I think I'm gonna go with the ebay special. It's a newly forged nitrided jobbie, so I think that'll work well, especially after a through balancing.
So I guess the general concensus is that this as21, despite a line bore, sleeved lifters, and flycut spigots and #1, is still going to provide me with 100,000+ miles of spirited daily driver type driving, provided I balanced the shit out of everything? |
That's my plan too.
There are no guarantees with 20+ year old cases, but I'd say that if you build it right, drive it smart, and stay on top of your maintenance you'll be just fine. There's a reason these things have been around for so long.
Keep me posted on your build if you feel like it, I'm in the middle of a 2276 build (slow paced budget style). Might help to bounce ideas and questions back and forth.
Just realized that was my first post, too. I've been lurking on these forums for at least a year and a half... shy I guess.  |
|
| Back to top |
|
|
Schatzi
Samba Member
Joined: April 29, 2012
Posts: 12
Location: Seattle, WA
|
| Posted: Tue May 08, 2012 4:50 am Post subject: |
|
|
| homebrew_86 wrote: |
2276 build (slow paced budget style). Might help to bounce ideas and questions back and forth. |
I was gonna do a 2110, but it's sounding more and more like I should just go with a 78 and choose my rods carefully.... So many decisions to make with this build still....
| homebrew_86 wrote: |
I've been lurking on these forums for at least a year and a half... |
lurk moar! |
|
| Back to top |
|
|
|
