Max HP out of a 409 block.

1964SuperStocker

Well Known Member
Supporting Member 2
#1
Sky is not the limit. What would a properly race prepped 409 engine block handle (blower, turbo, NITROUS)? 1000+hp on a factory cast block? If so, which casting? Seen lots of high HP motors but who has pulled the most out of which blocks? Z12 set up makes it easier to hit big numbers but what happens when I put a super charger/turbos with those Z12 heads and a shot or two of nitrous? Aluminum blocks not included. Who has hit the highest number before going NUCLEAR? These engines are designed with a slide rule. What can be considered safe is dependant upon the parts used, builders skill and experience.
 

Ishiftem

Well Known Member
Supporting Member 2
#7
Z12 set up makes it easier to hit big numbers but what happens when I put a super charger/turbos with those Z12 heads and a shot or two of nitrous?
You will wind up with two 4 cylinder engines.
RPM is a killer even with light components. I think MRHP is right that with 700 hp and good parts it shouldn't be much of a problem. I also think Don is right with 850 but, you better have damn near the best of everything and the tune needs to spot on. You would also need to be very picky with the block selection and preparation.
I talked to a guy who claimed 1300 hp with heavy nitrous. Nice guy and not an amateur but I don't believe him one bit. Had a lot of 409 stuff but his prices were as inflated as his hp claims.
 

Don Jacks

Well Seasoned Member
Supporting Member 3
#10
The piston design and weight are going to be limiting factors.I don't know how much it made,but the late Lamar Walden once split a production block right down the middle back in the 80's or 90's.I don't know if it was running nitros,or turbo's,but it blew up pretty dramaticly.
 

La Hot Rods

Well Known Member
Supporting Member 1
#11
I wouldn't be surprised to see 1000 to 1100 with a heavy hit of nitrous, on a dyno for a short blast.
If one was going to do this pass after pass, one better take a close look after every run.
 

tenxal

Well Known Member
#15
Honestly, I'd start getting nervous in the mid 600's if you're talking about any sort of longevity. With the piston weight involved, the cylinders can get pushed around pretty hard. At a minimum, a sonic tested block with adequate wall thickness, minimal overbore and a proper fill would be a must. A longer rod will help with the piston loading on the cylinder wall, also. Piston coating as done by LineToLine can help cylinder wall life quite a bit.
 

BSL409

Well Known Member
Supporting Member 6
#16
BSL 409........ he could probably tell ya..........
742E63AE-CC19-41DA-ABB6-4668FA535506.jpeg

This was my 814 car block with the Only 55MM cam made by Carl Mcquillen with over 820Lift, yes I believe the RPM is what split the cylinder wall. the engine was partial hard blocked I also believe if I had kept this under 7000rpm the cylinder walls would have been ok this engine took the 61 at 3650LBs to 9.40@140,89 MPH, this engine is now repaired and almost full of hard block and ready as a backup
 
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RussC

Well Known Member
#17
View attachment 68104

This was my 814 car block with the Only 55MM cam made by Carl Mcquillen with over 820Lift, yes I believe the RPM is what split the cylinder wall. the engine was partial hard blocked I also believe if I had kept this under 7000rpm the cylinder walls would have been ok this engine took the 61 at 3650LBs to 9.40@140,89 MPH, this engine is now repaired and almost full of hard block and ready as a backup
Very nice Brian...our last motor had almost identical results...785 @ 7500. We filled the block to the bottom of the water pump inlets. We had no failures.
Motor plates should be considered...we all recognize the blocks are prone to crack to the outside below the deck
 
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