Reply With Quoteloaders
I worked with my brother this weekend to gather some data on his pump and set up. This is a lake boat that we are mainly interested in top speed on gps.
He is running a small block but has seen 83 so don't say he needs a big block. He wants to optimize this set before the 468 goes in next month.
After talking to folks at Lake James, we decided to check pump pressures.
The first readings were 16# suction, 200# bowl. After removing the blocker loader and installing a "semi pro" loader the suction went to 22# and bowl pressure remained the same 200#. GPS readings also remained constant, I guess because we never increased bowl pressure. It has a stock place diverter with fixed 3.125" nozzle.
What should the next step be?
loaders
Are you runing a shoe and ride plate? 83mph is moving for a lake boat. 30-40 lbs is what your looking for at wot, at max speed. Consider this, you may be gaining with this set-up, but the extra weight of a Big block, not like the tuning, or set-up of the small block.
very true, we put a roller no2 fed sbc in a 18ft. 300lb cp tunnel and it would rear up real bad on a hard launch. had to pull out the saddle tanks and build a center mounted tank in the of rear seat betweeb stringers, to get the weight right in the boat. the boat came set-up for a bbc and was runnin big numbers with it, so the 1st set-up was right for the bbc. totally different numbers and issues with a sbc.
The boat is a 77 eliminator, full stringer, bubble deck. It has a stainless A impeller, precision jet drive inducer, and a loader I bought from Pro Boat.
The intake has been sharpened at the rear but no shoe. Small ride plate and old style place diverter.
The motor is a NA 406 with aluminum heads, about 11 to one, solid roller.
It turns 5200 RPM.
This boat is very weight sensitive as one passenger slows it 3 mph, verified on several outings. We have made one test with the big block in and it ran
more rpm but we had to pull it out to fix some water leaks in the heads.
The big block will stay in the boat when finished though.
Thanks for your insight
I'd leave the small block in it.
A little more suction pressure should help w/ cavitation (does not look like you have any)........and more bowl pressure comes w/ more hp (rpm).
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