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455 Update

I got some time off today so I went to the shop with a buddy who works there and we worked on the 72 455. We measured the deck height and checked the balance on the rotating assembly. It doesn't sound like much, but it ate up a lot of the day and we were interrupted a few times.

The new pistons are sweet and only weigh 465 grams. The Eagle rods are pretty heavy but the bob weight is less than 2300 grams. For comparison, an aluminum headed, roller cam 454 that went out a few days ago weighed in around 2500 grams. The crank was cut 0.50 on the rods (IIRC) for the BBC rods so the rotating assembly is a lot lighter than the stock setup; this engine should rap up pretty quick. In addition, the crank is going to lose a lot of meat to make up for all these changes so it gets lighter still. ;^)

The heads aren't done but the combustion chambers are looking pretty good.

Here's a link to a couple of pictures:

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Dave

Reply to
poncho462
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Nice work, what pistons are you using? Look excellent to me.

Reply to
BarracudaDesigns

They are custom manufactured by BRC Performance in Florida. Basically a Pontiac .030 over piston with a BBC pin diameter. The pin height is based on the stroke and rod length. BBC rods are not only stronger but they are cheaper that Pontiac rods. These pistons have a thicker crown since they will see a lot of nitrous use. The valve reliefs are good to .700 lift at a zero deck. I only know one shop that currently sells the custom line of Pontiac pistons.

Dave

Reply to
poncho462

poncho462 spilled my beer when they jumped on the table and proclaimed in

Looks good man! Let us know how it turns out.

NOI

Reply to
Thund3rstruck_n0i

I think I must be missing something here. I looked at the picture of the combustion chamber, which looks a good shape and nicely polished, but the valve seats overlap each other. If the valves are the same size as the seats they will trip over each other. The only way round this that I can see is that the exhaust valve is as big as its seat so that there is a good sealing width and the inlet valve is very little bigger than the port bore giving line contact on a radiused seat. But the seat doesn't look radiused or three angle. What have I got wrong?

Regards,

Reply to
David Toft

It's just an optical illusion. What you are looking at is replacement intake and exhaust valve seats. Click on the picture to see it larger and you can see where the intake valve seat has been cut into so the exhaust seat could be replaced.

...Ron

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68' Camaro RS 88' Firebird Formula 00' Mustang GT Vert
Reply to
RSCamaro

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