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Post by johnc118 on Nov 24, 2009 9:15:40 GMT -5
Ok, anyone know who makes the lifter valley girdle.. We split the block on a 347 yesterday on the dyno.
Had 553hp at 7300 and 427 lbs tq and on the forth pull the block split..
After pulling an all night disassembly and clean up, the parts seem ok and then someone mentioned they had seen a valley girdle setup for the smb that is suppose to stop this crap.
The only thing that held it together was the heads and intake, even busted the timing cover.
Back this am to steam clean the dyno room.
Same 347 build made 779hp on alcohol and a carb. The guy that built the fuel motor is thinking about a turbo.. Finalliny getting his act of the drag strip and circle track..
Salt fever!!!!!!!!!!!
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Post by w2zero on Nov 24, 2009 11:54:36 GMT -5
There was a lot of discussion of the valley girdle pieces that came to the conclusion that you are better off buying an aftermarket block. You would have to buy and install a bottom and top girdle and that still wouldn't make up for a lack of material around the mains in a stock block.
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Post by johnc118 on Nov 24, 2009 20:49:50 GMT -5
Had the bottom girdle, miced the crank and its bent, three rods bent all were forged eagle units. Thats $1500 shot. two pistons have the wrist pins bent... $5587.00 shooooot to hell in an hand basket...
Talked to Kieth Craft today and think I will go with the Man O War block, lots more nickle in the block and other things I did not understand. Man O war blocks are suppose to be stronger in the areas than even the Dart blocks.
Thought we were at 9.1 on compression,flat tops.lift on the cam was 615 and 598 with 307 duration. yea pretty bumpy but it was to put a super chager on later..
Back basics it will be cheaper to just buy a built block
The heads AFR 225 are fine, have some valve damage but the heads are fine..
So much for going to Bonneville next year, maybe 2011. My Procharger money is now going back to the motor.
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Post by w2zero on Nov 25, 2009 2:33:45 GMT -5
That just sucks so bad.
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Post by roy on Dec 12, 2009 19:48:21 GMT -5
I feel your pain
on the Dyno -
Final numbers for my little 342 are: 494hp/410lbs.
Using a 70 block.
The plan was to add a paxton but, because of the good dyno numbers we don;t think the block can handle the xtra omph of a blower or the Hellion single turbo system
In hindsite, we should have sprung for an aftermarket block.
We will be on a chassis dyno next week, see what the real workd numbers are & will post results
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Post by johnc118 on Dec 13, 2009 17:42:26 GMT -5
NOt even with the web valley gridle and bottom end girdle. The one short comming if the SBF..
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Post by w2zero on Dec 13, 2009 19:03:42 GMT -5
A further note on blocks. The Mexican block with the "knobs" sticking out on the front and heavier appearing main caps is NOT a stronger choice. While it appears to be heftier, it is just a result of castings from a different foundry. These blocks are also attributed to have "higher nickel" content too. Pure BS to drive up the price.
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Post by roy on Dec 15, 2009 14:41:24 GMT -5
Not totally true
I have a Mex. block & the main caps are larger than my 70;s mains caps, as far as nicket content, i think your right as i;ve never seen any proof of the extra nickel content rumor.
I didn;t use the Hencho de Mexico block because of a nasty gouge in cylinder #3, that i thought i could fix by sleeving, but, my engine builder, who has built engines for the likes of Force racing, agrees with you on Mex blocks
By adding a main girdle to the 70 bottom end, that also attaches to the block, an alum oil pan that is almost 1/4" thick that helps bottom end rigidity, screw in freeze plugs, forged internals, he says i;ve done all i can to help it live at around 400hp, but no blowers, turbos or nitros!
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Post by w2zero on Dec 15, 2009 18:13:08 GMT -5
At 400 hp, I wouldn't bother much with extra bottom end stuff. We used to run a 283 chevy with a 6.71 blower on it with a fabricated bottom end girdle but it definitely needed one. Your choice of a bottom end strap bolted to the mains is a good idea though. The guys splitting blocks in sbf's are mostly circle trackers pushing the limits to the maximum and limited to the stock block. They are dynoing right at 600 hp. Otherwise, the problem won't occur unless you are using power adders and run into detonation, which will blow the bottom end or side of the block out of anything.
I had a Mexiblock here and sold it to a Fairlaner for his 65 build. Yes the main caps are thicker appearing and there is extra iron in the block but it only amounts to 3-5 lbs. I sold him a complete engine intake to pan in a plastic shipping container for a hundred bucks. I got it for free from a Meteor guy who wanted to clear some space at mom and dad's place. Basically just stored it a while to keep in the hobby.
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Post by roy on Dec 17, 2009 11:58:05 GMT -5
I paid ALOT more than that for a Mexican block, only to find a huge gouge in Cylinder #3.
I may sleeve it in the future, just to save it.
Your right about the weight, mine is 4.5 pounds heavier than my 96 block, but, only 3 pounds heavier than my 70 block, go figure!
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Post by ca on Dec 17, 2009 14:39:33 GMT -5
i've read where the 68-70(?) blocks are spose to be the strongest due to metal content and that the mexican blocks were warranty and service items and were used primarily in trucks and vans. since there are variations visually couldn't they use the same amount of material and reinforce areas that may need it and i've read that the main webbing looks stronger/beefier in these things. just askin...........
why wouldn't you use a 351 block if you wanted a bigger stroke and could fit it? more meat in it and the taller deck would allow for longer rods to help reduce side loading which would help the block live.
maybe the cranks aren't made as good these days compared to the old stuff. nuthin worse on a block than a crank wigglin and flexin in a block along with high side loads.
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Post by roy on Dec 18, 2009 13:12:00 GMT -5
We;ve always wanted to build a hi winding little stroker motor that will buzz to 6500rpm safely.
And thats exactly what we got.
But, until we get on the street & track to actually expierence the dyno numbers, we won't know if we should we have pulled the Cleveland out of mothballs & built a big small block.
With 2 feet of snow on the ground its gonna be sometime until we know if we've gone in the right direction
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Post by ca on Dec 19, 2009 3:06:17 GMT -5
kinda hard to use stroker and high revvin together, no? you wanna do short strokes for high revs and strokers are for more grunt.
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Post by roy on Dec 19, 2009 12:30:07 GMT -5
Well, it makes
494@ 6500rpm
410 ft/lbs@5500rpm
at 2500rpm its making 380hp
We know it could go to 7K, but i;ll never visit there!
We consider this a hi-reving small block.
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Post by STU on Dec 19, 2009 19:30:10 GMT -5
Getting ready to build a 347stroker myself....The blower setup won't fit in the Merc without a pile of friggin around so I'm selling it to finance a stroker kit....I have a Hawk main girdle here with ARP studs.
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