for you guys using high boost

[Revere sho]

well i have a project car that im starting now and i was just wondering what block you guys are using for ure blower cars. im looking to run around 18psi but i was just wondering what blocks you guys are using. i heard a 94-95 block has better cooling passages than the 93 and under. are any of you running 93 and under blocks or are u running 94-95 blocks and what are ure thoughts on using a 93 block.

thanx for ure input in advance.

 

[sho_sc]

well i have a project car that im starting now and i was just wondering what block you guys are using for ure blower cars. im looking to run around 18psi but i was just wondering what blocks you guys are using. i heard a 94-95 block has better cooling passages than the 93 and under. are any of you running 93 and under blocks or are u running 94-95 blocks and what are ure thoughts on using a 93 block.

thanx for ure input in advance.

I'm running '89 internals (3.0l LC Wiseco Pistons). The engine had 200K miles on it when I pulled if from the SHO.

 

[Revere sho]

how much boost are you running? and does ure car run pretty cool.

 

[SHOMurph]

certain Texas SC car that runs mega boost......

no problems. Especially if you use one of SHO Bros new radiator.

 

[Toolman]

IMO, block differences are an urban legend.

 

[Revere sho]

oo cool thanx for the info.

 

[sho_sc]

how much boost are you running? and does ure car run pretty cool.

A bunch, currently I'm still in the tuning process with the "new" small pulley and I haven't run it hard...but I do have 1 data log where I'm seeing more than 16 psi at 6800 RPM. I run cool, big radiator ... but I'm not bored either.

 

[TedB]

Here is a handy resource:

I obtained it from Motion Dynamics' website, but I chose to omit the accompanying tutorial, which is severely flawed.

In a nutshell, for 93 octane, cross reference your compression ratio with the boost pressure that gives an overall figure of around "20". That should be considered a reasonable, practical limit for that octane.

 

[sho_sc]

Here is a handy resource:

I obtained it from Motion Dynamics' website, but I chose to omit the accompanying tutorial, which is severely flawed.

In a nutshell, for 93 octane, cross reference your compression ratio with the boost pressure that gives an overall figure of around "20". That should be considered a reasonable, practical limit for that octane.

So if I cross 8.5:1 CR with a 20 (19.8 in this case) that gives me 20 psi of boost at practical limit for "street gas" ... wonder what the "number" is with lets say 102 octane race fuel?

 

[TedB]

That number would be off the end of the chart.

Best torque is made when peak cylinder pressure occurs when the crank is around 15 deg ATDC. For any given fuel octane, there is a point whereby increasing the static cylinder pressure (boost or compression) further will not allow sufficient ignition timing to approach that point. When that threshold is reached, that is the limit of the octane in question, and no more power can be made. Increasing the boost further only necessitates retarding the ignition timing, which results in no more power, just greater EGT.

 

[sho_sc]

That number would be off the end of the chart.

Best torque is made when peak cylinder pressure occurs when the crank is around 15 deg ATDC. For any given fuel octane, there is a point whereby increasing the static cylinder pressure (boost or compression) further will not allow sufficient ignition timing to approach that point. When that threshold is reached, that is the limit of the octane in question, and no more power can be made. Increasing the boost further only necessitates retarding the ignition timing, which results in no more power, just greater EGT.

I'm not following in regards to the chart. Left side static compression, which in my case is 8.5:1 ... center of the chart I find a 19.8 (closest to 20) and the column heading is 20 psi.