Originally Posted by modracer64
I snagged a virgin 817 casting 400 block to build a 377 for my dirt modified, but when I talked to the machinist about building it for me, he pretty much said he'd rather not build anything using a stock 400 block.
I know compared to a 350 4 bolt main block (which loses the big bore benefit), bowtie block or Little M, the stock 400 is the weakest of the bunch. However, I figured at no more than 550hp and 7500 rpm with a short stroke, long rod, lightweight flat top rotating assembly in a 2500lb car would live for some time. This guy didn't want to touch a build like this PERIOD even with splayed main caps.
What are everyones opinions about using a stock 400 block with stock caps for this application? How long would it live? Will it live at all? What would safe power and rpm limits be before having to really worry about catastrophic block failure.
Thanks Guys,
Darren
Over the years we have prepared a lot of 400 blocks and afeter a season of running oly to find a cracks in the decks near the head bolt holes and we have seen cracks in the webbing from the cam tunnel down to the mains. And they are so far out o blue print compared to a good block its not funny.
Dart has the new SHP blocks that can be bored to 4.165 and I beleive we can machine one out, Line honed, decked, blue print bore and plate hone, clearance the lifter bores clean and ship in the U.S. for around 1795.00
We have 4 on order just waiting for them to arrive.