? Maximum Bore 454 Bow Tie Block

[ashbros]

I have a Mark IV Bowtie Block 454 Hy Per Series 9.8000 Deck
Numbers on Block are:10051107
4 Bolt Main
9.800 Deck Height
Siamesed Cylinders,

Anyone know what the Max Bore Size is on this block.

[nofear57]

GM Performance Parts books say 4.500"

[coloradoracerguy]

I had one that I bored to 4.600. Thinest cylinder wall after sonic check was .385". 4.625" is max safe.

Mark

[hammertime]

Have on thats 4.625 thats limit

[RonOwensRacing]

I don't think i would even try to take it out that far i had one and we bored it out to 4.460 and went thru on one cyld. and the four corners went to 4.500 .
so we went back sleeved them and i got another set of pistons and redone it .

[Tod74]

Wow I think I'd sell it and get a Big M or Merlin that is already 4.5 then you have room for some rebuilds. JMO

[fishmanjoe]

you will be taking away the shelf life of that sbc if you go boring it to the max.If I were you if you want big inches,go big block.FISHMANJOE

[hammertime]

hmm a bit confused a gm bowtie block is used as much as dart/merlin around here for 540 + builds and tall decks are very common to use for 632s for ts/td guys. The block is good and less money then a dart.

[Tod74]

Nevermind I misread the post. :oops:

[tcarda]

I have the same block and casting number, but mine started as a 502 and now it is a 540. How much hp can these Bowtie blocks handle?

[ashbros]

Well, I have ran over a 1000 hp 902 ft lbs torque
but I filled the block just below the freeze plugs
studded mains

[obsessedtruck]

We are dynoing some blower motors of my bosses. A 540 with a 14-71 on it and its at 2600HP. That IS with a bowtie block. He has had several in the past at 1600-1900hp using them.

[tcarda]

I just want to get close to 1000 hp with a Bowtie block and not have any worries and block filler.
On a different note, I just received my new Edelbrock 24 degree heads from RFD and I cannot wait to put them on my 540 and go to the dyno.

[alexu]

We just did an OLD Bowtie ProMod done by Gene Fulton . I contacted him to find out how much I could hone. His response was no more than needed. It was 638 ci. We decided to resleeve it and there was more cylinder wall to spare. Installed sleeves and went on with life.

[Rupturedduck]

I have the same block and casting number, but mine started as a 502 and now it is a 540. How much hp can these Bowtie blocks handle?

MY:cool: BLOCK IS AT 4.625/4.250 STROKE=572 cu.in/850hp AND Iam TOLD THE BLOCK CAN GO 4.750.

[lmgator56]

I would have it sonic checked to see how thick your cylinder walls are that will tell you how big you can go

[curtisreed]

I would hope since 2009 that he figured it out. LOL

[oldandtired]

MY:cool: BLOCK IS AT 4.625/4.250 STROKE=572 cu.in/850hp AND Iam TOLD THE BLOCK CAN GO 4.750.[/QUOTE]

Not sure why this string came back to life but you will never get 4.75 out of a Bow Tie block.
Oh wait, use the water jacket as the exhaust and run it 2 cycle.

[zimmer626]

I just want to get close to 1000 hp with a Bowtie block and not have any worries and block filler.
On a different note, I just received my new Edelbrock 24 degree heads from RFD and I cannot wait to put them on my 540 and go to the dyno.
11 years later I have an old pair of 24 degree Victor heads. How did they do on the dino?