Offshoreonly.com - Holley HP EFI conversion

Offshoreonly.com (https://www.offshoreonly.com/forums/)

- General Q & A (https://www.offshoreonly.com/forums/general-q-20/)

- - Holley HP EFI conversion (https://www.offshoreonly.com/forums/general-q/365834-holley-hp-efi-conversion.html)

Quote:

Originally Posted by sutphen 30 (Post 4772400)

what cam are you gonna run or thinking about running.to get a 454 to make 560hp gonna need a cam in the 240,248 range w/ lift to match heads

When I was at 252/264 I was just over 600. When I went down to 235°/241° - 0.646" I was thinking ~550. This put my TRS Scarab Panther to 82 and my non-stepped 37 Active Thunder to 75. My heads flow 404 @ 0.650" and the exhaust flow extremely well also, 300 something. I forget the number though. New cam is 237°/243° - 0.684". The dyno numbers are fun to discuss, but end results in the boat are what really count. I went faster in my Panther with smaller cam, less compression, less HP. I assume more torque and bringing the RPM's down. Getting peak TQ and HP closer together. 5600 vs 6500 RPM.

Quote:

Originally Posted by articfriends (Post 4772332)

Think it was one of those weird holley blower kits that bolted on top of a MPI lower manifold on a mpi engine, if Im thinking of same motor me and frank talked about

It's the one we talked talked about. Its a 256 on top of an b&m MPI manifold with the MPI throttle body. I figured it would pull past 5k but it was done at that rpm.

Quote:

Originally Posted by Panther (Post 4772548)

It's the one we talked talked about. Its a 256 on top of an b&m MPI manifold with the MPI throttle body. I figured it would pull past 5k but it was done at that rpm.

have any pics?

These just arrived today. Any guesses?
.
https://cimg1.ibsrv.net/gimg/www.off...77dfbc2511.jpg

Made more progress tonight. Finally received my 8AN extension fittings and 90° fittings to finish the front union for the fuel rails. Primed the oil system, disconnected injectors and coils. Hooked up the laptop, checked the sensors and turned it over. Oil pressure and fuel pressure were good and starter turning it over at 155 RPM showing on the tach. There are a ton of wires on the odd bank of this engine. I believe 13 different items wired in 7 looms running between valve cover and intake.
I should be lighting it off tomorrow.
.
https://cimg0.ibsrv.net/gimg/www.off...4d7e28d363.jpg
https://cimg1.ibsrv.net/gimg/www.off...e6060416c1.jpg

awesome! Very nice package.

Well... It lit today! Caught me off guard and scared the s#it out of me! I was just bumping it over and didn't remember I plugged the injectors back into get the connector to get it off the flywheel. I was bumping it over to look at my balancer to check the timing while just turning it over. After 1 rotation all hell broke loose. The engine fired right up, I jumped out of my skin! Fireballs pouring out of the heads. All frazzled I didn't have a clue how to shut it down. After a few seconds I regained my composure and turned off the ignition switch. I cussed and swore for a bit while taking the event in. I didn't have the headers on, no O2 sensors hooked up, no map and no plugs in the throttle body.

After I had everything hooked up properly I tried to fire it up again. It needed a lot of throttle to get it to run and would not idle on its own. It was throwing a ton of fuel at it and the shop was full of smoke and unburned fuel. While at home tonight I looked at the fuel map and it's extremely rich. I compared it to other base tunes and they were nowhere near the same. I wrote another tune off of those fuel numbers and will go try it again tomorrow.

Ha! ran when you didn`t want it to and didn`t when you needed it to . lol '
Been there.

Took me a day and a half to get mine started, I screwed up clocking and setting up the dual sync.
The relief when it finally fired off after an entire year off was overwhelming.