Thread: need help, pisron hits valve

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Originally Posted by Dave Severson

I'm certainly no BBC guy, but should the piston be that high out of the block or am just seeing things in your picture????? Looks like the top of the piston is dang near 1/8" above the block?????

NO dave there ok he doing some thing worng with the way he checking his PV them are not big look at them 638 or 632 on my photos them are big domes

when i did my farm boy rebuild on my cadillac engine i put the head on and put a piston at tdc and carefully let the valve down on the piston and actually measured the distance of valve drop without a gasket ugly and fast, but it worked to see where i was in relation to valve clearance with calculating lift and rocker arm ratio. I wasnt anywhere close to a clearance problem but it gave me an idea of where i was at.
I agree Pat he has to start somewhere cause it wont work the way it is now. I deferr any thoughts to you cause any advise you have ever given has been spot on.
If i ever want to build my 454 i am going to ask you for shure for some good advise

Stupid question but hard to tell from pics: is piston in backwards?

well after reading thru here and looking at the pics I have come up with the answer-----first it does look like the piston is out of the hole some and it could possibly be a 427 piston instead of a 454 piston--the putty is NOT marked from valve contact----I think he cranked down too far on his adjuster nuts and the retainer hit the guide/seal, never touching the piston

Originally Posted by skids72

Stupid question but hard to tell from pics: is piston in backwards?

water ports for heads cooling are in back of the mark 4 block and open so your looking at the front of the block os that number one hole and is right ? from what i can see ???????????????????? mark 5/6 are open front and back but the mark 5 cnc bowtie is plug in front to make the water go thru the back of block