HP 500 w/blower

[Daytona 25]

Has anyone added a blower to a HP 500 carb without reducing the compression? I only have 35 hours on mine and would rather not tear into the short block.
Any suggestions?

[Infomaniac]

What is the reason for adding the blower? :D
HP500 pistons have about .100" dome on them.
You can add the blower, only run a couple of pounds of boost. You will need 91 octane minimum.
Will not make as much power as dropping the compression and running 8-10 lbs.

[Whipple Charged]

With only 35 hours, you can supercharge the stock engine, stock compression. Run 5-6lbs of intercooled boost, one heat range colder spark plug, 30 degrees total timing, 91 octane minimum gas, 100-120deg operating temp and 20-30lbs of block pressure. Should be able to get an easy 700+hp @ 5400rpm with stock everything.
You should have no problems with that. That package has been very, very reliable.
When it's time to rebuild, go to a 509 or 540, MSD ignition, replace heads with AFR CNC 335/121, 8.5:1 - 8.8:1 compression, 632/632 lift, 256/264 camshaft and you'll make very near 900-1000hp depending on rpm.
Thanks,
Dustin

[jackpunx]

I have had mine for about 150 hrs.. HP500, whipple 3.3,, Alum Dart heads, Cam, Dominator 1050 and MSD..Running 8lbs of boost on 91.. Just bumped it to 9lbs on AV gas.. Loving it.. I want to take it down and bump it to a 540 but its hard to take something apart that is not broken..I also run it to 5500 RPMs with out any issues so far..
Good luck.. I love mine..
BTW.. I added mine with 27hrs on it.. I change the oil , service the drive , change the water pump impeller and the water separator every 20-25 hrs ....

[Infomaniac]

Alum heads and good head gaskets were a plus for your blower addition.

[Risky Business]

Daytona:
I have the same boat with a HP and whipple. Over two years with good gas and zero problems. Also had this same package in a 25 v-bottom and almost 300 hours having only to change out the valve springs. Easy on the boost (5-6 pounds) and the motor should live.

[HP350SC]

I'm going to have to chime in here and recommend head gaskets (Fel-Pro 1047), valve springs and wider seats on the valves.That is if you keep the stock heads. I'm running a Whippled GEN VI HP500 w/3.3 at 9 lbs. 31 deg. total on straight 100 LL and 1090 Demon and Crane HI-6M with no problems@5500rpm (other than fuel delivery) :cool: ) Just My 10K :wink:

[SHAKEN Not Stirred]

:D

[cjordan]

Anyone have thoughts on going 8-71 no chiller, @7# boost and carbed on 500EFI running 93 Octane? What power do you think would be expected?

[HP350SC]

You will be OK but at the edge with no chiller. Keep timing at 30 deg.
Head gaskets are a MUST!

[Daytona 25]

Daytona:
I have the same boat with a HP and whipple. Over two years with good gas and zero problems. Also had this same package in a 25 v-bottom and almost 300 hours having only to change out the valve springs. Easy on the boost (5-6 pounds) and the motor should live.
What type of speeds are you seeing with that setup? Do you have a low water pickup drive? I would appreciate any additional details.
Thanks.

[Risky Business]

What type of speeds are you seeing with that setup? Do you have a low water pickup drive? I would appreciate any additional details.
Thanks.
Daytona:
Boat runs 90-94. Depends on load and weather. I am running the big pully (less boost) but do know of people running the exact same set up with more boost and they see 100mph. Drive height is also pretty critical. I switched to a 2" lower and picked up 8 mph.

[HP350SC]

Do you have a low water pickup drive? I would appreciate any additional details.
Thanks.
Just thought I'd mention that I went with a Merc. Sportmaster with low water pick up. It is impossible for me to pull up to a beach, and not plug up the outdrive. Also will suck up 1/4" sized pebbles. I'm switching to a thru-hull water pickup as one of my winter changes.

[cam-shaft]

Your 25 Daytona should just crack into the 100mph mark with the Whipple on the HP500. A 26 daytona will run around 100-105 with 700hp and you should be right there with your set up.