'87 Scarab 21

[Scarab 21]

Finally, we have the new build ready and installed for the SC1. Went from a 300hp 5.7 to a mild built 355.

(1981 4-bolt K block, steel chev crank, 218 / 224 cam / Trick flow 180cc alum heads / beehives / forged rods / slugs, flat tops, light ring pack, RPM intake and 1409. Stainless Mar. manifolds)

Figuring the lessened weight and added hp and torque should reliably put this hull at 65+ Excited to get it dialed in and get the summer sandbar going. Cheers from Ontario fellas.

 

[racerone]

Pottahawk point ?

 

[alldodge]

Over 65 with a 21 footer, might be a bit of chin walk

 

[kenny nunez]

I see you have Captain’s call exhaust. Just curious, when the boat was full throttle was there a difference in top speed & rpm with open or closed exhaust?
Nice looking engine and boat.
The reason I asked this is the previous owner of my 18’ Donzi with the 383 MPI said it would do 70 With open exhaust. When I replaced the transom and gimbal housing I went back with through the drive exhaust. It went 70 @ 5500 on GPS.

 

[Scarab 21]

Pottahawk point ?

South shore Rice Lake Ontario

 

[Scarab 21]

Over 65 with a 21 footer, might be a bit of chin walk

We'll have to keep it under control ")

 

[Scarab 21]

I see you have Captain’s call exhaust. Just curious, when the boat was full throttle was there a difference in top speed & rpm with open or closed exhaust?
Nice looking engine and boat.
The reason I asked this is the previous owner of my 18’ Donzi with the 383 MPI said it would do 70 With open exhaust. When I replaced the transom and gimbal housing I went back with through the drive exhaust. It went 70 @ 5500 on GPS.

With the CC out the back, it breathes a bit better, but it had the stock Mercruiser boat anchor manifolds and 882 heads.

With the new engine setup and TF heads, it'll breath much better. They re only 180cc, but have a strong exhaust port. Hoping it ll work strong with the SM manifolds. Keep you posted.

 

[Scarab 21]

We're taking 180+lbs out of the rear, so the 23p Mirage should have a positive effect to get the bow up with the stern.