Lifter Bores and Block Strength

[blackgn1]

Look at these lifter bores. Notice the material that has chipped away. From searching a old thread showing a similar block I too believe this is from the metal cooling too quick in the casting mold. The thread didn't go any further to tell if it was ever used to build the motor. I'm wondering if this block is safe enough to build a high horsepower engine. I'm going to take it and have it checked at the machine shop but looking for someone who has pushed a similar block to a high horsepower level.

 

[blackgn1]

Nobody?:biggrin:

 

[750H.P.V6]

It looks fine to me I'd use it.

Neal

 

[turbobitt]

This is very typical of iron castings. I wouldn't call it "Chipping". It is most likely from pulling the mold away, worn mold, or the sand wasn't properly packed. It also may have been caused by someone breaking off the extra material with a hammer after it leaves the mold.
Allan G.

 

[Just a Six??]

Mine has 1 chip out of one bore only & been fine for many rebuilds & like that since I remember. Thats how I know its My Block at machine shop after a year!

PS: I left it at the shop he is not taking too long & I didnt mean that. Finally starting the spare again over winter.

 

[blackgn1]

Thanks guys. Anyone else with any comments let's here them. Going to contact the engine builder soon.:biggrin:

 

[A2000RICH]

Thanks guys. Anyone else with any comments let's here them. Going to contact the engine builder soon.:biggrin:

the area you are concerned with contributes virtually nothing to overall strength in any way towards any of the general weaknesses of these blocks-------------if it breaks its not gonna be one of those lifter bores

 

[blackgn1]

I agree. There's alot of material in that area.

 

[Rich Scaz]

That will not present any problem. Need to clean the rust out. You may want to bush the lifter bores to pick up some oil pressure.

 

[Sam Colalillo]

I would smooth those edges out releiving any stress concentration points, if that is all that is wrong with it. in my opinion, if your valve train geometry is correct you wont have any problem. The lifter shouldn't create side loading in that area.

The 109 block splits right down the center under severe detonation. The cracked blocks I have seen have a crack all the way down the center of the lifter valley. (red dashed line shown below). It starts at a center main bearing cap (or main stud) , walks up to the cam bearing area, and works all the way up to this portion of the block.

In some instance I have seen this crack walk up the side of the lifter bore, but in my opinion this was not because the lifter bore was week. The block was trying to rip itself in half under severe detonation.

 

[Sam Colalillo]

Here is a photo of a 109 block that must have expierianced some massive detonation. I believe it belonged to Tony O.

Look close:biggrin::biggrin: and you can see the one crack which really put a damper on things.

 

[blackgn1]

Holy crap! Right down the center. The block I have is in such great shape. Stock bore and the bores look great. Just the lifter area chipping. Called the machine shop today. It has an appointment for a complete check up and cleaning.:biggrin: Going to have everything checked!