'96 252 454 Magnum performance benchmark

[akorcovelos]

Yeah great nasty idle. Let’s make a hit!!

You have no idea how bad I want the lakes to open!

[xlint89]

Suspense is killing me. Any word on when she'll be in the water?

[akorcovelos]

We had it out last weekend, but the lakes were absolutely insane, so couldn’t really push the boat without pummeling my family.

I did get it up to 60 gps on a short hit, it had more but I ran out of clean water. Not bad considering my previous best was 60 on fumes with no gear, and this time it easily pulled to 60 with 73 gallons of fuel, both built in coolers full, and all the junk we drag along, like 3 big bags. I think it will hit 62-63 empty in good conditions.

I still haven’t checked timing yet either, and it feels like it needs another degree or two of base timing.

Honestly the best thing about all that work is how easy this thing fires up now. I literally tap the key without touching the throttle and it jumps into a nice steady idle, and I can hold any rpm without surging. Runs like a new boat, and those manifolds make the swim deck a nice foot massager, lol. Much deeper rumble you can feel in your chest.

I had the sea pump belt start slipping towards the end of the weekend, I didn’t put enough tension on the belt. I have all new v-belts coming Saturday. Still need to install the new exhaust flappers too.

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[Big Block Power]

Very cool. But really running out of clean water? You weren't on lake Michigan. You boat on a sewer like I do there is no clean water

[cmattj]

Very cool. But really running out of clean water? You weren't on lake Michigan. You boat on a sewer like I do there is no clean water

Haaa. Yes we look at the term clean water as not dodging clumps of muck

That is so awesome AK. That a real world test right there!! Awesome job pal

[akorcovelos]

Haha, yeah different kind of clean, as in this only brown:

[AsLan7]

.
Yes,great job akor. . Your hard work is paying off buddy.

.

[xlint89]

Nice. Thanks for the follow up. Can't wait to here the new top speed.

[akorcovelos]

Well, PSA for today is don’t reuse those old rubber exhaust couplers...

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Couple hard pulls and smelled burning rubber. Checked the bilge and saw water coming in from the exhaust somewhere. Tore it down today and found that.

I should have replaced all the rubber exhaust hose when I swapped manifolds. I have 4’ of 4” Shields wet exhaust hose to replace everything but the transom couplers which are in great shape.

[xlint89]

Interesting. I wonder why you're getting so much heat concentrated in one spot?

[akorcovelos]

Interesting. I wonder why you're getting so much heat concentrated in one spot?

When I looked close it seems the angle of the exhaust hose was making the hose contact the flair at the end of the exhaust trumpet. That’s also right where the upper water exit is , so I’m guessing it was restricting water flow at the top and the exhaust gas was un-cooled at the upper trumpet exit. I’m going to cut an inch off the end removing that flair, should do the trick. Also going to the heavier steel wound reinforced rubber exhaust hose will help as it has a higher temp rating. I should point out the risers themselves never got hot. Even after extended WOT runs I can comfortably rest my hands on both risers.

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[Big Block Power]

Interesting. I wonder why you're getting so much heat concentrated in one spot?

When I looked close it seems the angle of the exhaust hose was making the hose contact the flair at the end of the exhaust trumpet. That’s also right where the upper water exit is , so I’m guessing it was restricting water flow at the top and the exhaust gas was un-cooled at the upper trumpet exit. I’m going to cut an inch off the end removing that flair, should do the trick. Also going to the heavier steel wound reinforced rubber exhaust hose will help as it has a higher temp rating. I should point out the risers themselves never got hot. Even after extended WOT runs I can comfortably rest my hands on both risers.

F478E94D-2A71-4DF0-9220-2389573CEFAF.jpeg
01386C56-7497-4DDD-916D-2CA08D0226FD.jpeg

Buy the looks of that you are going to have bigger problems.
Why did you cut the manifolds in half? Now your going to have water and exhaust fumes all over the place. Buy some JB Weld quick

[akorcovelos]

Interesting. I wonder why you're getting so much heat concentrated in one spot?

When I looked close it seems the angle of the exhaust hose was making the hose contact the flair at the end of the exhaust trumpet. That’s also right where the upper water exit is , so I’m guessing it was restricting water flow at the top and the exhaust gas was un-cooled at the upper trumpet exit. I’m going to cut an inch off the end removing that flair, should do the trick. Also going to the heavier steel wound reinforced rubber exhaust hose will help as it has a higher temp rating. I should point out the risers themselves never got hot. Even after extended WOT runs I can comfortably rest my hands on both risers.

F478E94D-2A71-4DF0-9220-2389573CEFAF.jpeg
01386C56-7497-4DDD-916D-2CA08D0226FD.jpeg

Buy the looks of that you are going to have bigger problems.
Why did you cut the manifolds in half? Now your going to have water and exhaust fumes all over the place. Buy some JB Weld quick

Light weight though!

[Bleil05]

Hi Akor
Impressive numbers on the boat
One lesson I learned from my local speed shop is to put an oil temp gage on these motors when you modify them
Once the oil gets over a certain temp it fails even though the motor temp is within specs
I would hate to see it scatter over oil failures

[Big Block Power]

Hi Akor
Impressive numbers on the boat
One lesson I learned from my local speed shop is to put an oil temp gage on these motors when you modify them
Once the oil gets over a certain temp it fails even though the motor temp is within specs
I would hate to see it scatter over oil failures

Another reason I use BGMOA additive.