I have a 3999289 P block that has been bored out .060. I have been told that it's possible to go out to .120, I just want to know if it can be bored out to .090 over?

Sonic check the cylider Walls is only way to know how big it can go.

quote:

I have a 3999289 P block that has been bored out .060. I have been told that it's possible to go out to .120, I just want to know if it can be bored out to .090 over?

As Green1 stated, sonic testing is the only way to really know. I have two "289" blocks and both would be stretching the limits at .060" over. My machinist prefers thick cylinder walls over a slightly larger bore, I have a few blocks he doesn't even really like at .030" for a decent effort race engine.

Keep in mind though, I wanna go 600 runs at least and this time around, I'm shooting for 800-1000 runs before a freshen up. Most of the people I know that go big on 454 blocks don't sonic test them and don't get nearly that many runs outa their stuff.

I have a 289 block, that the machine shop who sonic tested it, said it would easily be good for +.100" overbore. I went .060 to be safe. Later on, a dropped valve nicked a cylinder pretty good, so I had that bore sleeved. Now I am thinking about going to the +.100 overbore. How thick are the sleeve walls to begin with? (Does a sleeve for a 454-based engine begin with a 4.250" bore, and is then honed or bored to match the target bore size)?

While you have it Sonic checked, pay close attention to cooling jacket scaling. Specifically at head bolt area. Have had some on these early blocks pull the threads right out of the deck.
Has to do the Time-Sert deal. Like 4 on one side and 3 on the other.

If your machinist used a .090" wall sleeve then there should be approximately .060" of sleeve thickness left with a 4.350" bore.

If he used a sleeve based on the stock 4.250" bore the sleeve walls will only be .040" with a 4.350" bore.

.090" is kinda the norm because there isn't much original cylinder wall for support left with a .120" wall sleeve.

But either way, I'd be inclined to NOT use a sleeved stock block with a 4.350" bore.

You can usually buy a .060" over block pretty inexpensively. BUT try to buy it with the understanding it will sonic check OK for a 4.350" bore.

Good luck with your project...

We used to fill 4" stroke blocks with 6.135 rods to add some stiffness on blocks that checked a little thin. That was in the 80's with earlier, maybe better, blocks. Is filling a block an option for a marginal wall block these days?

Dave there are a couple of blower intakes on racingjunk.
https://www.racingjunk.com/Int...offset=3&from=search

quote:

Originally posted by Bruce Williams:
Dave there are a couple of blower intakes on racingjunk.
https://www.racingjunk.com/Int...offset=3&from=search

Yeah I saw that one Bruce...If I don't find one at the Long Beach Race Parts swap meet this Sunday I'll probably buy that one. Not exactly what I'm looking for but I guess BBC blower manifolds are rare now days.....

quote:

Originally posted by imakehp:

quote:

Originally posted by Bruce Williams:
Dave there are a couple of blower intakes on racingjunk.
https://www.racingjunk.com/Int...offset=3&from=search

Yeah I saw that one Bruce...If I don't find one at the Long Beach Race Parts swap meet this Sunday I'll probably buy that one. Not exactly what I'm looking for but I guess BBC blower manifolds are rare now days.....

What exactly are you looking for?
There not rare.
Just add to cart