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Project Muscrate

Part 3: Life goes on

by Jay Roeder
5/7/04

ello again and welcome back! First off, I would like to thank DRO editor Jeff Burk for his patience and understanding in waiting for my article. My father passed away on April 2 from complications of heart bypass surgery, so I have had other issues to deal with. While I'm at it, let me take this opportunity to ask each of you, when was the last time you had a physical? My dad waited too long, and now my family is without him. It is a horrible pain, and times such as these can really be a wake-up call. I am going to get a physical. Thank you for listening.

Here you see the 89 302 HO 2 bolt block being used for the 302/320 hp "crate motor ". Nothing fancy about this one.

Now, on to a better topic, racing! In the last installment I explained some of the rules and specifications involved in the preparation of the cylinder heads for "Muscrate". One thing I forgot to mention was that there is also a spec. for the minimum combustion chamber volume on any Stock Eliminator cylinder head. Every different head allowed for Stocker duty has its own specs. as per IHRA/ NHRA blueprint sheets. My old combination, 89 302 HO, used an E7TE-PA casting number head and had a 60.6 cc minimum chamber volume. In most instances, there is NO room for error; 60.5 cc's would be illegal. Obviously, most people will mill their respective heads down to the smallest volume they believe will pass tech. The smaller you go the more compression you have. In Stock every little bit adds up. Muscrates heads however, are a bit different. The heads for Muscrate are a Ford Performance X302 casting and have a minimum chamber spec. of 64 cc's, +/- 2 cc's. I have never seen a + or - before associated with chamber volume; must be a "crate motor" thing. Anyway, my heads cc at about 65 cc's so I am just going to leave them alone for now.

Here we see the old pistons from the 302 HO combo. They were made by CP PISTONS and are part # F5CP. The new pistons will also be made by CP and will look pretty similar but not have a dish.

Next, the short-block. In the photos I show you a picture of my old 302 HO pistons, made by CP Pistons. They were required to be a dish piston with four valve relief's and have a total negative volume of 4.6 cc's. The new pistons that I am expecting shortly, also from CP Pistons, are listed as flat tops with four valve relief's and a negative volume of 3.4 cc's. Also, the combined piston and pin weight must be a minimum of 709 grams each. I will post pictures of the new slugs as soon as I can. CP Pistons makes some really nice pistons. The accuracy of dimensions and attention to detail is second to none.

Also, I have a couple of pictures of the block I'm using. It is a standard duty lightweight casting that comes in everything from Mustangs to pickup trucks. It is also the same block I have been running the last two seasons and has not been apart since I built it in 2002. It is UGLY. With approximately 250 plus runs under its belt, it needs a fresh cylinder wall finish. I am actually quite surprised it ran as good as it did last fall after looking at #3 cylinder especially. Oh well, thatÇs partly due to the crappy soft cast iron the factory used when they cast it. Trust me, there is a BIG difference in the quality of iron used in old (mid å70s back) blocks and the new "stuff". In order to even have a chance at minimizing cylinder wall distortion in these blocks, I have the water jackets filled to the bottom of the water pump holes with Hard Blok block filler. It actually helps quite a bit.

This UGLY picture is of cyl. #3 after teardown. The marks are mostly from moisture accumulating in the cylinder over the last two seasons of use. In Iowa we get to race in some VERY humid conditions at times and just letting the engine set for a week with an exhaust valve open can let in enough moisture to do this. This will clean up with about .002" of honing. Not COOL!

Another stocker rule is that you cannot overbore more than .070" from stock size. I am going to be at .062" oversize. That is absolutely the limit for one of these blocks with block filler. The cylinder walls get pretty thin when you bore past .030" over. But, it is the block I'm using, and it is already .060" over. It will take a good .002" more to clean it up with a hone.

Also pictured is the block with a deck plate attached. The deck plate will help simulate the distortion the block sees when the cylinder heads are bolted on. The plate makes a big difference when you try to get the cylinder's round and straight within two ten-thousandths of an inch (.0002") top to bottom. Ring seal and low friction is the key in any racing engine short-block. The connecting rods and crankshaft are stock Ford pieces from my old engine which used the 89 302 HO externally balanced assembly. The crankshaft is so spindly that it could easily be mistaken for something out of a Briggs and Sratten. The good part is that it is really light. The potential bad part is that it might break under the stresses of my hopefully newfound horsepower. I guess we'll find out!

Here we see the deck plate bolted to the block. This helps simulate the stresses on the block that the cylinder head bolts exert when torqued to spec. It is VERY important.

Also, I am using an ATI Super Damper to control the harmonics. I use ATI dampers almost exclusively at my shop because they are the best. The bearings of choice are Federal Mogul "H" series pieces. The "H" bearings are affectionately nicknamed "ugly" bearings because they come from FM without the silver flash plating you normally see on standard bearings. The reason for this is that the silvery tin plating can actually peel off under high stresses and try to become "as one" with the crank journals. For bearing clearances I will run about .0025" on rods and .003" on the mains. The factory Ford standard pressure oil pump is plenty adequate and takes fewer horsepower to turn than a high volume or high-pressure pump does. Also, it is made from aluminum so it weighs less. Remember, every little bit adds up. I can add weight in the rear of the car if it comes off the front. The piston to cylinder wall clearance will be about .0055" total. The unique shape of the CP Pistons skirt allows me to run a tighter clearance than would normally be associated with a racing piston and still have very low drag. The rings are Speed-Pro Plasma Moly file fit types and I will set the

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end gap of the top rings to about .016". A stock or possibly stock replacement type oil pan will be used and a few baffles added for oil control.

In the next installment I will cover the selection and installation of the custom ground Comp Cams hydraulic roller cam I am using and the intake manifold selection, show some engine assembly and hopefully have a finished powerhouse to install in Muscrate. See ya next time! Remember, life's too short.

When in doubt, DO
A WHEELIE!!