Knotching cyllinder walls

I have oversize valves on a 429, heads are D3ve-A , intake 2.25 and was wondering if I should notch the cylinder edge next to the intake valve?

My compression ratio is around 9.8:1.

Bob
Tucson

Not in my opinion.

+1 no reason for it.

Put the head on the block, make a hook scribe and scribe the chamber around the cylinder. Might give you something to think about.

Not needed with that combo.

Do any heads need that to happen on a stock block?

Meaning do the SCJ's or P51's with the larger valves?

or even the A460 with the 2.35 valves?

wilmus wrote: Do any heads need that to happen on a stock block?

Meaning do the SCJ's or P51's with the larger valves?

or even the A460 with the 2.35 valves?

I think KJett notched his for his A460 build. I'm not sure of his valve size though.

wilmus wrote: Do any heads need that to happen on a stock block?

Meaning do the SCJ's or P51's with the larger valves?

or even the A460 with the 2.35 valves?

I don't look at it form a valve size point of view, I look at how the cylinder fits the chamber (or vise verse). It might help cylinder head flow a little but how about flame propagation from the chamber into the cylinder?

wilmus wrote: Do any heads need that to happen on a stock block?

Meaning do the SCJ's or P51's with the larger valves?

or even the A460 with the 2.35 valves?

The TFS A460 chamber is the one that is wider that most bores.

I guess what I was asking is would there be any valve contact on a stock block with stock bore if any of those heads were used?

I saw a pic that Lem posted (I think) that showed a fairly large amount of space between a cyl bore and the SCJ heads and its valves

I was wondering if the TFS A460 heads had enough room as well ?
As to not have the valves hit a stock BBF 460 bore?

75truck wrote:I have oversize valves on a 429, heads are D3ve-A , intake 2.25 and was wondering if I should notch the cylinder edge next to the intake valve?

My compression ratio is around 9.8:1.

Bob
Tucson

Some cylinder heads have chambers bigger than the bore ... I believe that the D3VE chambers are not.

My Motorsport A460 heads with a 2.35" Intake valve had to have notches on a 4.39" bore block. No notches were needed when I switched to a 4.44" bore block.

FWIW Mark

68formalGT wrote:

wilmus wrote: Do any heads need that to happen on a stock block?

Meaning do the SCJ's or P51's with the larger valves?

or even the A460 with the 2.35 valves?

I think KJett notched his for his A460 build. I'm not sure of his valve size though.

I did on my 4.42 bore block. The valves did barely cleared the walls, but we did it more to help unshroud the valve more with such a small bore and big head. It worked out well for my application/build, but may not be needed for another.

wilmus wrote: I guess what I was asking is would there be any valve contact on a stock block with stock bore if any of those heads were used?

I saw a pic that Lem posted (I think) that showed a fairly large amount of space between a cyl bore and the SCJ heads and its valves

I was wondering if the TFS A460 heads had enough room as well ?
As to not have the valves hit a stock BBF 460 bore?

Factory heads with 2.25 valves do not need notched on a 4.36 stock bore

Just curious, I have had to notch small bore with blue thunder heads is this normal? I just copied the notches from a 351c. Still pretty close with a 4.390.

slurm wrote:Just curious, I have had to notch small bore with blue thunder heads is this normal?  I just copied the notches from a 351c. Still pretty close with a 4.390.

Can't speak for the BT heads if they had 1.88 exhaust valves and Chevy ports never played with those, factory type stuff dosent need it to work.