JPR

An Iron 6.0 liter block? I am putting together an "all bore" project for a customer and I am clueless to whats the max size would be before cooling/pressure crack problems? anyone know? TIA!

Joe Prince

Chicago Crew UnderBoss

iTrader: (1)

As we speak MTI is finishing my 427 ci LQ4 and i my intensive research on this has shown that the general consensus (including Jayson at MTI) is that 4.060 is the max bore for naturally aspirated applications, but of course, you MUST sonic test the block to make sure that there is enough cyl. wall thickness, as many ironblocks are not thick enough.

Most recommend going with a max of 4.030 for N20 of other F/I, and even many recommend staying with 4.030 for N/A so that there will be enough cylinder wall thicknes left in case a rebuild ever has to be done with that block.

MY MTI 427cid will achieve those cubes by going with a 4.060 overbore and a 4.125 crank.

Hope that helps,

MTI 427 C5 Roadster

<small>[ February 25, 2003, 10:29 AM: Message edited by: MTI 427 C5 Roadster ]</small>

rodent

iTrader: (1)

Just be sure to sonic test the block. I was going to go .060 over on mine but the walls are too thin. I made a post in this section about it. .030 would be much safer.

Chicago Crew UnderBoss

iTrader: (1)

Yeah, as mentioned in my post also, SONIC TESTING the BLOCK is a HUGE MUST! I have heard that more blocks than not, are not thick enough for the 4.060 overbore and that is why SONIC TESTING is a must. Obviously going with a 4.04 overbore or 4.050 is another possibiliy, also depending on what the sonic testing shows concerning cylinder wall thickness.

Good luck,

MTI 427 C5 Roadster

<small>[ February 25, 2003, 09:56 PM: Message edited by: MTI 427 C5 Roadster ]</small>

Linear Velocity

iTrader: (1)

I'm going with a 4.125" bore with an LS6 block in my 388 <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> They don't use a darton sleeve, they used a stepped one so it won't slip. I'll keep you all posted when the motor's running.