To gridle or not to Girdle, That is the question.......

[Dominic]

Correct me if im wrong but if you tie the pan rails to the mains wont that help hold it from splitting? You would think that tieing everything together would help stop that sort of failure???? Maybe im dumb??

Not if it cracks above the girdle

Kinda hard to explain but if you seen one crack where mine did you will see what i mean. If the girdle is bolted down and you cracked the block straight thru the upper mains the girdle will still be attached to the block but the block will still be in two pieces. Same problem the Ford guys have with stock 302 blocks. It's just too weak above the mains. A main girdle is exactly what it say it is, it just ties the mains together not the whole block.

From my expierences they break on the same plane as the bottom of the cylinders or in that area.

 

[87natl]

Forged stroker with steel mains, no girdle here. I ain't sweatin'....yet.

 

[BetMinesFaster]

I guess everyone is entitled to an opinion, but it should be qualified.

We have done MANY girdled 109 blocks and lots of these are in GN's running high 9's. With the girdle and forged internals, the weak link is then the block itself. We have 3 recent 109 blocks from 9 sec. GN's that have split the main webs.

A mid to low 9 sec. 109 build should be "checked" about every 25 runs, if it makes it. When you put 8-900 HP through a 109 block, it is way beyond its design limits and expect the worst in a short time.

For a mid-10 sec. build, if the tune is perfect, it should last with forged internals and caps. Push it harder than that, a girdle would be a must.

The 109 block is ~50#'s lighter than a stage block. All that extra metal is to strengthen the stage block, and many of them have given up at the 1100-1200 HP level.

Like was stated, why spend $10K or more on a 9 sec. build and NOT include a girdle.

Nick, im happy with your explanation here, Im thinking that when I deliver my engine I will be delivering it with an RJC girdle and will request it to be installed with my build, Its sure not gonna hurt and its cheap insurance!