cap walk

[mally69]

what exactly causes cap walk  and why is it a big factor with stroker motors,    i thought cap walk was from running high rpms.    the reason why im  asking this is because im building a 512 stroker  that probably wont see anything over 6000 rpm and just wanted to know alittle more about why it happens

[Challenger340]

Boy, this is gonna be a Loooong thread !

How about # 5 main is the fulcrum, so number #4 gets the hammering ?
#3 holds again, and #2 gets walloped with whatever remains from #4,
and,
#2 again, gets whats coming from #1 as a fulcrum, to external load at the front.

Sorta Like when the old man was driving the Newport, He'd get mad at you kids in the back goof'in off, so he'd reach around and "swing" blindly, you'd DUCK,
but your brother get smashed "full pop" in the cakehole, with the old boys bankhand !

You'd start laughing at your brothers misfortune, turn around, just in time to get Pops returning forehand on the flipside !

Dunno how he did that either !

[mally69]

         im lost ,,  how could i prevent this from happening i was planning on using the stock main caps

[firefighter3931]

  how could i prevent this from happening i was planning on using the stock main caps

You can't ! By using a ductile cap and main studs you can slow down the capwalk issue. Metal transfer is inevitable a stroker power levels in a factory block. Some folks are using an aluminum main cap to help slow down the capwalk and it works pretty good. The aluminum cap also helps cushion the main saddles by absorbing some of the beating from the rotating assembly. A main girdle wouldn't hurt either. 


Ron

[mally69]

so, building a stroker is pretty much usless with my factory block  becuase all its gonna do is eat itself up quicker  right?

the BEST  bet your saying is buy a mega block or an aluminum block from indy???

[firefighter3931]

so, building a stroker is pretty much usless with my factory block  becuase all its gonna do is eat itself up quicker  right?

Nope, i'm not saying that at all. Many have built strokers with factory blocks and had good results. The "if it were mine" answer would be to upgrade the caps and use a girdle. I'm in the same boat and will be building a stroker in the future. Aluminum caps, main studs and a girdle is what i'll be using when the time comes.  Opinions may differ.....


Ron

[mally69]

oh ok       well im  gathering all the info that i possibly can before i jump into this, which will be  probably next week or the week after. 

Firefighter,  do you have any places in mind that sell aluminum caps main studs and a girdle  that i can buy before hand so that i have them ,, i know id have to get it line bored but no big deal really.

All help is appretiated 

[firefighter3931]

Firefighter,  do you have any places in mind that sell aluminum caps main studs and a girdle  that i can buy before hand so that i have them ,, i know id have to get it line bored but no big deal really.

Funny you should ask 


Main caps : http://www.bcrproducts.com/

Girdle kit > comes with studs and all related hardware : http://gearsandrears.com/girdle.html

* The girdle kit is available with a notch for an internal pickup which will work fine with the 4.25 stroke/2.20 rod kit from 440source 

Tha alum caps and girdle combo will make for a bullit proof bottom end good for 650hp. The only thing better would be a megablock or KB/Indy alum block but those are 4+ grand. 


Ron

[mally69]

yea those blocks are defintly costly,

i hoping to have around 600 to 650hp  tops  no more than that,, im planning on using indy ez-1 heads  with an indy manifold  2'' tti headers and  havent decided on a cam yet probably a costom grind from scott brown  or a new hyd roller cam from comp with 75cc heads i should right around 11.1 compression

thanks for those 2 pages defintaly going to purchase  both     

[Runner]

does cap walk happen all the time, or just under heave loads, id think it would be just under heave loads?  also isnt detonation suposed to cause some of the problems?   in a race motor that would be most of its life , but in a street motor would happen much less ( unless you drive like me  )      isnt cap walk more of a hp level problem than a stoke or cb inch problem?   i guess what im asking is, would a 493 making 600 hp experiance more cap walk than a 446 making 600hp?.      ive wondered weather my 452 is experiacing this from time to time, but im hoping i just dont make enough power, andeven if i do theres not much i can do about it sence the junk is screwed together. 

     do cross bolted blocks have less problem with this? i know someone makes caps for a factory block to get cross bolts.   if someone would just make   

    i always look back on biulds that i do and wish id done things different,  on my 452 i wish i would have biult a 470, aftermarket rods, and a higher quaility piston, and an aftermarket crank.  but then i remember what a finacial burden it was to get the parts that i did use  .     

[mally69]

firefighter,    would i need to get a 3/8 longer oil pickup  since the girdle is 3/8 thick

[mally69]

does cap walk happen all the time, or just under heave loads, id think it would be just under heave loads?  also isnt detonation suposed to cause some of the problems?   in a race motor that would be most of its life , but in a street motor would happen much less ( unless you drive like me  )      isnt cap walk more of a hp level problem than a stoke or cb inch problem?   i guess what im asking is, would a 493 making 600 hp experiance more cap walk than a 446 making 600hp?.      ive wondered weather my 452 is experiacing this from time to time, but im hoping i just dont make enough power, andeven if i do theres not much i can do about it sence the junk is screwed together. 

     do cross bolted blocks have less problem with this? i know someone makes caps for a factory block to get cross bolts.   if someone would just make   

    i always look back on biulds that i do and wish id done things different,  on my 452 i wish i would have biult a 470, aftermarket rods, and a higher quaility piston, and an aftermarket crank.  but then i remember what a finacial burden it was to get the parts that i did use  .     

[Chryco Psycho]

you should be able to Adjust the pick up 3/8" down

[firefighter3931]

isnt detonation suposed to cause some of the problems? 

 in a race motor that would be most of its life , but in a street motor would happen much less ( unless you drive like me  )     

isnt cap walk more of a hp level problem than a stoke or cb inch problem?   i guess what im asking is, would a 493 making 600 hp experiance more cap walk than a 446 making 600hp?.      ive wondered weather my 452 is experiacing this from time to time, but im hoping i just dont make enough power, andeven if i do theres not much i can do about it sence the junk is screwed together. 

 do cross bolted blocks have less problem with this? i know someone makes caps for a factory block to get cross bolts.   if someone would just make   

    i always look back on biulds that i do and wish id done things different,  on my 452 i wish i would have biult a 470, aftermarket rods, and a higher quaility piston, and an aftermarket crank.  but then i remember what a finacial burden it was to get the parts that i did use  .     

To answer Runners questions :

(1) yes detonation contributes to cap walk and it also kills bearings, pistons etc...Detonation should be less of an issue on a race engine assuming the tuneup is good and the correct fuel is being used. Street guys trying to push the pump gas envelope are probably more likely to experience detonation than an all out race type build that is well scienced out.

(2) High hp combos are more prone to the capwalk issue, inmo. Strokers also create increased load on the bottom end and make more hp/tq because that's their purpose. Those caps are fluttering at high engine speeds and metal transfer is inevitable....but you can minimize it. Using a softer cap will protect the block and the girdle should keep evrything all tied in together.

(3) Cross bolted blocks are not immune to capwalk, unfortunately. 


(4) High end parts don't necessarily guarantee that there won't be capwalk. I've seen pics of a well built megablock race combo that was suffering from severe capwalk which is disheartening given that the crossbolted mains are supposed to eliminate that issue. Perhaps it was detonation that caused it....who knows 


This is a subject that will get beaten to death and debated forever.....there will be lots of opinions either way. Based on what i've seen and read : the aluminum cap/girdle is the way to go for a stout factory block build in the 600+hp range. Some might argue it's overkill and hey, that's their opinion. I prefer to err on the side of caution. 

Additionally : any block being used in a stroker build should be sonic checked to verify structural integrity. 




Ron

[firefighter3931]

you should be able to Adjust the pick up 3/8" down

[defiance]

As a note, I've noticed that Mancini sells a pretty reasonably priced caps/girdle combo
http://chucker54.stores.yahoo.net/400440blgi.html ($600) -
Anybody have any opinions or experience with this set?  I was looking at getting them seperate, but that price is hard to beat if they're a pretty good set (which they look like to me, but I'm no expert )

[firefighter3931]

As a note, I've noticed that Mancini sells a pretty reasonably priced caps/girdle combo
http://chucker54.stores.yahoo.net/400440blgi.html ($600) -
Anybody have any opinions or experience with this set?  I was looking at getting them seperate, but that price is hard to beat if they're a pretty good set (which they look like to me, but I'm no expert )

I noticed those as well...looks like a nice setup. The only thing i'm not sold on is the caps....the ones in the Mancini kit are ductile iron. As stated previously, my preferance is for an aluminum cap.




Ron

[kamkuda]

I noticed those as well...looks like a nice setup. The only thing i'm not sold on is the caps....the ones in the Mancini kit are ductile iron. As stated previously, my preferance is for an aluminum cap.


Ron

Ron Sold on Aluminum Now.  Hmmmm, I recall this conversation a number of months ago buddy LOL

Ron would you agree that the aluminum caps allow for less stress on the main webs of the block and absord /cushion some shock from the Crank.

Just a quick note, if you add a girdle, you will have to look at your pan clearance.  My stock pan and milidon pan are already pretty close to the centerlink with stock motor mounts.  The girdle will drop it lower requiring some oilpan work.

[firefighter3931]

Ron Sold on Aluminum Now.  Hmmmm, I recall this conversation a number of months ago buddy LOL

Ron would you agree that the aluminum caps allow for less stress on the main webs of the block and absord /cushion some shock from the Crank.

Ya, i wasn't so convinced awhile back....but now i am !  The alum is just better at absorbing harmonics and protecting the main webs than ductile iron. My initial apprehension to the alum was due to durability concerns....some alum caps were prone to cracking. Still a cracked cap is better than a wasted block that has had thousands of dollars of machine work performed to it.   

The latest generation T6 caps seem to be holding up pretty good in race applications. 


Ron

[kamkuda]

Still a cracked cap is better than a wasted block that has had thousands of dollars of machine work performed to it.   

I am with you brother   

[Blown68Coronet]

Hey Ron/Kamkuda
I'm going the same route for my blown 446. Alum cap with girdle, already have the stud kits. This way i'll have peace of mind as far as the bottom end goes, it's my weak link of my build.

I'm waitin to see if BCR products comes out with his new design alum cap/girdle which should be ready in next couple of months.

Kamkuda
Next time your up we(Ron,you & myself) so grab some & wings!

[kamkuda]

Hey Kevin.  It would be a sound investment in that bullet of yours!  I have some parts that I will need to get from Ron in February.    and wings is 

Rob