Thread: Need our engine experts to help me out.

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Originally Posted by jerry clayton

two items come to mind that haven't been mentioned---Bolts that hold cam plate on may have heads that are too thick to clear the gear--- some aftermarket cam gears are wider and hit block area above the oil galley area, plug you put into galley may not be deep enough causing back of chain/gear to hit it,and also some strokers have interfernce at where the oil pump mount area is on block(counter weight hits.

also ---fuel pump eccentric????

ok maybe more than 2 but I'll only charge for two!!!!!

well if that was so that would make for bad things as the timming set would be hitting cutting in the back of the cam gear making iron as well as you may have seen this when you TQ the cam bolt up the gear would of only turned 1/2 way and hit the bolt ?? or not at all . but if so you would have had a false TQ read on the cam bolt and would in time make the cam gear loost and you would have a loose chain or the added load would work your chain set making it loose

well on all engine after boring i roll the lower bore so that will not happen i use a 80 grit flap wheel if you do not do this it will shave the pistons skirts the outer ring is loose but this will have a load on it as the fule pump arm is loaded

That makes a lot of sense Pat. What do you think about the scoring on the same 2 areas of each cylinder. Is that from piston slop or what?

Don

I just thought of something. Maybe the piston skirts rubbing on those sharp edges is where my black dirt is coming from?

Don

the piston skirt comes out of the bottom of bores the bigger stroke on some of the big engines you can allmost see the oil ring landas for the mud i hope that your piston did not get tore up that bad them bore sould of never left the machine shop like that.... some one needs there nuts nailed to there chin for that one .. it could be from that

I saw some walls like that in a Boss 302 engine once----the pistons were press fit on the pins and when it was put together the piston boss was squashed on one side from the pressing in of the pins----it was so tight that the piston did not want to wiggle on the rod, in fact they were so tight that the engine was hard to turn over by hand---I took the piston/rod assemblies apart for the guy and honed the pistons to remove the squash area and reassembled with my sunnen electric pin deallie and the engine was then fine

Luckily Pat, the pistons show no scuffing anywhere. I think with more time they might have. You know, I have used the same machinist for 25 years or more and he has been good, but I think I am going to try the other guy in town next time. Strike one was the galley plug popping out. He blamed in on "oil pressure momentarily spiking." I was watching the gauge, it never got over 60 psi. Strike two is the sloppy bores. Like you said, he shouldn't have left them in that condition.

I will do the flap wheel routine you mentioned, good idea. Now Pat, what about those vertical scuff marks at 12 and 6 oclock on every cylinder. Are my pistons rocking as the stroker crank travels out to its full sideways position, or what?

Don

Sorry Jerry, I missed your post. These are full floaters and they move extremely easily. I checked for locking clips not staying in and all that stuff, and they are fine. It just looks to me as if the increased stroke is for some reason pulling the piston to the 12 and 6 oclock side of each cylinder. Could it be too much piston to wall clearance? I can take a couple of them and very slightly move the piston up and down in the bore. Not a lot, just like it is moving on the rings a tad. By up and down I mean sideways in the bore.

Don

yep jerry i fixed pistons like to to many times nothing like seeing black death in the pin bores from to tight lack of oil ... i have guys from FL send me up there parts and engine to fix that kind of dip $hit stuff .as for the bores, break the bottom of the bores with the flap wheel on a air grinder stuff rags in the cam bearings so not hot stuff gets stuck in them if you can hang your finger nail s in the marks in the bore s you may want to hone them bores out with a hone with stones or a ball hone you may never get them you with out making the bore way big .did you use file fit rings ? what happens don with the 12 and 6 is some of the metal hanging off the bores gets inbeded in the skirts an cut in the walls will show up on the skirts as shinny small marks on the skirts you need to pick all of them out of the skirts

I'm heading over there now again with my camera and will take some pictures and also take a second look at the pistons and the bores.

Thanks guys,

Don

Now that it is Monday and some businesses are open, I called Scat this morning and also Keith Black Pistons. (I thought I had Probes, they are actually KB) Told Scat guy about noise/ odd pattern I am seeing on cylinder walls, he was some help, but suggested I check all the clearances and go from there. KB guy was more help, also told me to check clearances and that I might have to start over with a virgin block and bore each cylinder to match the pistons.

I called a local engine builder who has been there for about 40 years, and I have an appointment to drop off block and parts tomorrow to have him check the clearances and all. When I mentioned the vertical scoring on the walls he said trash in the oil + washing the cylinder walls could be the cause. I KNOW I am running way too rich with the 2 600cfm Edelbrocks, there is some black carbon already building up in the insides. What I am going to do there is store the 2 x 4 setup for a while and buy a new single 4 barrel aluminum intake and run one carb until I can get this thing dialed in, then try to jet the carbs or something so I can reinstall the 2 x 4 setup. I have too much money in this engine to wipe out stuff just because I want the looks of multiple carbs.

The Keith Black guy told me one of the prices you pay with a stroker kit with forged pistons is that they can be noisy until they warm up, and the short pistons accentuate the noise. I asked him if it would sound like a knock, knock, knock, and he said yes. He said he knows of 331 and 347 strokers that sound like that normally until they warm up! I may have to run with my headers open all the time so I don't have to listen to that.

The machinist I spoke to agreed with Pat that the bottoms of the bores should have been polished smooth, and if the block turns out to be savable he will do that and anything else he sees. If not I will be hitting a junkyard looking for a standard bore 302 so I can have my NEW machine shop bore it to fit the pistons.

Here I thought I was being so good in buying cool parts that I have never used, and I never thought it would create other problems. I'll let all of you who helped with suggestions know what I find out when they mic the parts.

Thanks again guys,


Don

Don

We build and ship those all the time, generally have Dart blocks on the shelf, get scat and callies cranks by the dozens, etc--any time we can help you with parts I am generally on here all the time.

Thanks Jerry, I may take you up on that. I thought I might just buy a brand new bare block and have it bored 30 over and start anew. Then I priced them! I'd like to be able to afford food for the next year or so. If this block is not savable I may hit the local pick and pull and try to score a virgin 5.0 out of a Crown Vic or something that was setup for a roller cam. I'd sacrifice the engine out of my own Crown Vic as it only has 76,000 on it, but it is a pre roller cam motor.

Thanks again for the offer.......we'll see what happens tomorrow. I hate to scrap the one I have because it has been bored, align bored, decked, etc. But of it is out of spec I have no choice.

Don

I dont know what the block has been bored ,but I am sure you could sell it to someone who could bore it further or clean up the bores and order some pistons for it.....not a total loss anyway if you have to get another one it might help offset the cost a little.

Don. Don't give up on that block yet. With the new honing machines they have now, they may be able to clean up the bores without creating too much piston to wall clearance. And the forged piston can stand the extra clearance, but they will be noisy as mentioned. Let us know what piston clearances you have. Maybe you will be set up on the tight side and have some room to clean up further.