Got a few pictures of the block before I take it to the machine shop. I finished the oil mods tonight so I'm going to drop it off at the machine shop tomorrow. Based on advice from the oiling link that Sleepy sent me and from Barry's book, I bored the pump-to-filter gallery out to 7/16" and used a die grinder to round and chamfer both holes at the filter boss mount. I'm planning to also install the #69 holley jets in the galleries to the rockers and run a Melling high volume pump for extra insurance. I think that should be adequate for this mild build. Here are the pics of the prepped block:







Check out the scratches in the bore! This is the reason for the bore job.



The crank shows some scoring as well. It will probably have to be turned .010" under.

 

WOW that cylinder is marked up ! any ideas what caused it ?

 

The way that cylinder is scuffed, I'd say there's a good chance it overheated, and the piston expanded to the point where it scraped the cylinder.

 

thanks for the info

 

krewat,
that explains the bottom scuff, but the piston skirt doesn't go as high as that really deep gouge.
Almost looks like a ring broke, or at the least had a sharp edge or something.

sucks, hope it isn't too deep.

Drew

 

True. However, there are marks way down below where the rings would stop, so the skirt did scuff the cylinder at one point. Without seeing the piston, who knows what happened

 

If you don't debur the ring ends, you can get vertical scratches like he did. The bottom damage had to come from the piston skirt.

 

Kinda makes me wonder if something else wasn't "roaming" around inside the cyls...... Something that shouldn't have been there.

 

There was no other damage inside besides the cylinders, but the thing has been apart, so who knows. The pistons/heads look great.

I called the machine shop yesterday and they said that 0.030" might not be enough to clean it up, but he is fairly confident that 0.040" will clean it up. I don't think I want to go to 0.060".

I need to buy pistons before they can cut the cylinders (he wants to measure the new pistons to get the clearances right). I want to get flat top pistons to get the compression up a little. I'm looking at these: Keith Black/KB Pistons 1131H-040 - Silv-O-Lite Hypereutectic Pistons - Application - SummitRacing.com

They are a hypereutectic flat top piston. Does anyone see any issues with running these? It says that these use press-in wrist pins, where the stockers are floating C-clip style. Can I reuse my stock wrist pins and press them into these pistons? Any advice would be helpful.

 

I can't comment of the pistons themselves, as I have no experience with them.

As for the pin, press in vs c-clip. The press-in pins float in the piston, it's the rod where they are a press-fit. Using the stock pins and rods with pistons designed for press fit pins would require cutting a groove for the c-clip, assuming the pin diameter is the same.
Press fit pistons typically require rods that are designed or modified to accept the press fit pin.

 

There are plenty of guys here that can give you some good information on this.
Remember that if you use hypereutectic pistons, they do not like any power adders. In a mild application they are very good pistons. It is not a good idea to reuse piston pins. In fact for my racing applications, exact tolerances are essential or piston failure can occur. Pistons normally come with new pins, and I always mic. the new pins and pistons, for the proper clearance. Sometimes you get pins that are to loose or to tight from the manufacturer. With a mild build and hypereutectic pistons, your machinist will bore and hone the block with tighter tolerances than with forged pistons.
Bad idea to reuse piston pins, if you want your engine to last.

 

Thanks a ton for the info, I was not aware of that with the wrist pins. This motor is just a mild build and I can guarantee that it will never see power adders. It is going into a stockish Highboy that will be a weekend street cruiser. It will not see hard use at all.

On a side note, how do you deal with a "too loose" piston/pin combo? Find another pin that is tighter? What is considered "too loose"?

 

Hypereutectic pistons require tighter piston pin tolerances. On Keith Black pistons, they suggest .005 to .008 for a stock application. On a race engine the tolerances for a forged piston pin would be above .010 depending on piston alloy and engine use. If the piston pin has to much clearance, of course you can not adjust for that, so you send the piston and pin back and get another one. When the piston pin is to tight, the machinist will ream the piston to the desirable size. Most people either don't know or don't care about clearances, and that is why some engines run smooth and trouble free, and others blow up. Look up information about "blueprinting" an engine. It takes a little more time, but is well worth it. I turn 7000 rpm with a two bolt main 434ci FE with no problems. Anyone could do the same, if they adhered to some specific engine building techniques. With nitrous, we will be about 850 hp shortly. At those levels, if I did not do my job correctly, the thing will fly apart. We will see.

 

I havent read Jay's book but I thought that I read here that the streetmaster stacked up really well against the dual planes due to the smaller runner size, no? Sheesh, and I am just about to buy one for my F100..........

 

The information that I am getting is that it works just as well as a Performer RPM in the upper range, but will make slightly less torque than the RPM does in the lower rang due to the shorter runners. From what I can gather they outperform a Performer (non RPM) intake greatly in the upper range and only suffer in the lower range. I am trying to maximize torque in the lower range for this engine, so I'd rather go with the Performer RPM. That is, as long as I can sell the Streetmaster intake...