470 machine work

Ok people, what are the minimum machine work requires on a 470. I know the following but what am I missing
Oil mods
Square Deck height at 10.550
Bore 4.35
Offset grind crankshaft 0.050 (2.200)
Polish crank

For a 500ish hp build should the cam crank tunnels be align honed?

I plan to balance the rotating assembly but do I need to get the internal balanced flex plate and harmonic balancer or can the originals be reused if they are ok

 

crank should be alone honed for sure......everything else done on the block like decking, boring, etc all is based off the crank tunnel being corrected. its step 1 in building after the block has been inspected and measured.

internal balance isnt needed. in fact it cost a good chunk to go that way, the metal used isnt cheap.

stay external, but a better balancer and flex plate are good investment in the long run

 

Thanks Larry and Ben. Yes I have Jim’s 470 combo on order along with TAs alum heads.
Ben appreciate the advice.

 

We just did a complete block work job for a board member in Wi.. we took videos, and I am going to post those on the new TSP website we are working on, and then link them from the board here, it goes thru the complete block work process in detail.

Services are:
Sonic Check cylinder walls
Align hone mains
Square and deck to 10.550 with BHJ fixturing
correct dowel pin placement for transmission
Re-positing cylinders with regard to the sonic test results to maintain max cylinder wall thickness possible
Overbore engine
Hone with Deck plate
Balance rotating assembly

This block also had the cam tunnel and lifter bores Blueprinted.. the cam was tipped down .008 in the block, it also had the lifters resized and squared to the cam.. angle was off considerably in the block, it is the first one we have seen that left a shadow in a few bores after being corrected.. the angle seems to be more of a concern than placement laterally. The average lifter bore to lifter clearance was .0025, with several past .003.. this is your low oil pressure at idle issue, ideal lifter bore clearance is .0015.

Cam tunnel/lifter angle correction becomes a concern when we start putting higher spring rate valve springs on the heads, to deal with the needs of a performance camshaft. The factory, using valve springs with 80-90 lbs on the seat, and 200 open, could get away with a lot.. increased spring pressures, and more aggressive profiles often result in excessive cam wear, that can lead to premature failure. And for sure it is changing cam timing, cylinder to cylinder, and costing you power.

Cam tunnel location/angles also cause excessive distributor gear wear, which shows up as a failed gear at worst, or at least timing jumping around all over the place, costing you power.

Worst yet, if the lifter angle is wrong, this can lead to lifters not spinning on the lobe, and will result in failure at break-in, or shortly thereafter.

Buick engine builders have long speculated that cam tunnel problems/lifter angle problems were causing those cam failures that could not be pinned on anything obvious. All proper procedures and supplies/oils were used, yet the cam still fails.

In addition to this, cam angle issues compromise valve timing, costing you power.

"Can you check and repair a cam tunnel and lifer bores in a 455 Buick"

Until recently, the answer to this question was NO.... Regardless of who you were talking to.. in fact, it was very rarely even checked, because the shop owner/builder on the other end of the phone did not have the tooling for a low volume engine like anything that says Buick on the valve covers. Exclusive Buick builders like myself had not made the investment in the tooling to do it.

Now the answer is Yes, we can.

At TSP, we can now do you a fully blueprinted iron block, we are able to offer this service now, because the expensive tooling required to do it, was purchased because Ken Betts decided that he wanted to bush the lifter bores in his New Wildcat block, for long life and maximum versatility. Thus the tooling had to be purchased. It also allowed him to insure the placement of the cam tunnel and lifter bores.. CNC's are not perfect, nor are the folks who run them. It was decided in the engineering phase of the project that the cam tunnel and lifter bores would be left a couple thousandths small, and the more precise process of finishing with the cam tunnel and lifter tru tooling would be used.

And now everyone can benefit from that Wildcat block project, even if your doing a factory block... you no longer have to leave these critical dimensions and fits to chance.

In the future we will be stocking fully machined blocks, for immediate delivery.


JW

 

Is this something that can be done to a v6 block or is it just for the big block?

 

Is the cam/lifter alignment an issue or could be an issue with the 350 block?
Or you don't know yet as Im sure you do WAY more 455's than 350's
A lot of the issues you mentioned as far as higher spring pressures and such makes sense with the lifter/rocker/valve clack issue I've had for years.
The only thing that remedied the issue was removing the inner spring, resulting in lower spring pressure.
NOTHING else helped or changed anything.

 

Mark,

Your correct, due to the low volume of 350 Builds, it will be tough for anyone to justify purchasing the tooling to do the cam tunnel work to the 350. One would have to check and see if the 350 and the V-6 share the same main to cam tunnel dimensions, it would help if they did, even though we reached the peak of the V-6 turbo stuff a while ago.

Yes, valvetrain noise that cannot be addressed without dramatic changes, and unexplained cam/cam bearing failures are some of the symptoms of cam tunnel/lifter angle issues.

JW

 

350 and V6 are the same cam to crank centerline. We have this tooling. I had Mike make it along with the 455 stuff.