Possible 4.8L Build

[PolloLoco]

I am looking for the uniqueness factor .. but im also looking for the best bang for my buck. Its actually a cheaper build going with a 4.8 as the pistons are way cheaper than kb944's.

kb944 = 607.99
kb364 = 336.39

Arent the 944's just a standard "D" dish? cause its the same on the fords...

So you think i could get better performance with a 4.7L build? Even running on pump gas (premium is fine)? That may be the determining factor then ...

I came up with this post from googling "uem-kb945-060"
viewtopic.php?f=15&t=225#p2481
You listed $607.99, all 8-sets cost that much. It looks like you can order a set of six for $478.69, should help the wallet a bit.

Again my googling comes into question with my previous post in this threat.

[Mgardiner1]

KB945 have an 11.38cc dish (high compression ratio)
KB944 have a 21.73cc dish (lower compression ratio)

[oletshot]

I must admit, after clicking on the link to the ford pistons, they are quite interesting!

[Muad'Dib]

Now you got me all confused!! lol

[Muad'Dib]

Does anyone else have anything to add to this thread?

Can i really squeeze better performance / numbers (HP/Torque) out of a 4.7 build rather than a 4.8?

[mendelmax]

Can i really squeeze better performance / numbers (HP/Torque) out of a 4.7 build rather than a 4.8?

I'm a newbie here, and I've built only one stroker so far, but I'll share one thought. It is a HUGE estimation, and cannot be used for precise calculations, but gives an idea of what to expect.

There is an empiric formula about the performance gain from compression ratio rise. It assumes that all other parameters (timing, rods, pistons, fuel grade etc) are exactly the same. It is

NP= OP x (E2/E1) ^ (0.365 x n)

where:
NP- new power
OP- old power
E2- new compression ratio
E1- old compression ratio
n- number of cylinders

So, what I meant to say is that with for example rising CR from 8.8 to 9.2 on stock, 4.0 190HP I6 you can get 210 HP. A 10% improvement. To achieve the same from the displacement you'd have to bore it to 4.4 liters at stock 8.8.

What I mean is that doing engine properly, with really good quench and high CR you can easily outperform the 0.1L bigger engine that had to be made with certain compromises.

[jsawduste]

FWIW I went .080 over on my 93 block. No heartburn thus far. The engine has gotten HOT several times from slow wheeling in heavy mud plus forgetting to turn the electric fan on after a water crossing...... :doh:

[Muad'Dib]

FWIW I went .080 over on my 93 block. No heartburn thus far. The engine has gotten HOT several times from slow wheeling in heavy mud plus forgetting to turn the electric fan on after a water crossing......

What pistons did you use? Custom?

[Muad'Dib]

Bump ..

And i also found out today there is no one in the area who can sonic check a block! WTF!! im screwed.

[Plechtan]

I just saw a tester on ebay, only $1,095.00 Maybe uou can rent it out to the local engine shops. Also comes with a probe for heads to measure port thickness.

[yuppiexj]

I sense another "expensive tool" rental dealio coming up.

if only I had $1000 to invest in a sonic tester

[Muad'Dib]

Man .. i'm really sceptical about getting machine work done in my area now if they are all saying they don't have a sonic checking machine... I mean really what kind of machine shop doesnt spring 1-3,000 for something like this.

I hope i dont have to take my stuff over the cascades and into the valley just for decent machine work.

[Plechtan]

you anywhere near Salem? tru this http://www.salemspeedshop.com/ if they cannot do the work, they can tell you who can.

[Muad'Dib]

Salem is over the Cascades in the valley... im hoping to avoid that. (Salem is about 150 miles away over the mountains) Im "Central Oregon"... which technically can be considered eastern oregon. There is nothing really "decent" east of the Cascade mountain range it seems..

[jsawduste]

FWIW I went .080 over on my 93 block. No heartburn thus far. The engine has gotten HOT several times from slow wheeling in heavy mud plus forgetting to turn the electric fan on after a water crossing...... :doh:

What pistons did you use? Custom?

Diamonds, who are also the supplier to Hesco.

Moved the pin for the Eagle rod and set it for a zero deck. 9.56 calculated compression with a .042 gasket.