My 78 Sonic 496 stroker build project!

[fbpd227]

I bought this 78 Sonic, local, by Lake Hartwell, SC/ GA line, for a song and dance, with a blown up 350 engine the p/o put in out of a van, using Mercruiser parts. The paint and interior were already done by him, so that's saving me alot of $$$$ to put towards my 496 bbc stroker build!!
I'll start with pics of the boat, and progress as I do with the project.
Hope you enjoy as much as I will!
I'll try to keep pics coming as much as possible, since I know how much I like to see pics in others projects!!!

[fbpd227]

First order of business is to get the old sb 350 crap pile out! Wasn't too hard, except I now know I'll need a longer boom for my cherry picker!

[fbpd227]

Now..... on to gathering needed parts!
First off, a solid foundation for my build..... a nice gen IV 454 4 bolt main block!

[fbpd227]

Then I ordered my 496 rotating assembly..... don't have pics of that yet, because It's actually being shipped to me this week. Took a few weeks longer, since I wanted everything fully balanced.
Here's the basics:
Fully forged kit-
Forged Scat 4340, internally balanced crank.
4.250 stroke
.125 radius on rods and mains
And "rated" for 9000 rpm and 1200hp.

4340 forged H beam rods
6.385 length

Wiesco forged racing pistons with 18cc domes.
The Weisco site talks about the better forging material they use and coatings for friction and all that, but until I'm holding them, all I have is the internet to refer to.

I had this entire rotating assembly balanced, as I'm a firm believer in balanced assemblies!!!

All the King rod and main bearings, moly rings, etc comes with, making my life a little easier......
Onto gathering more parts!!!!

[fbpd227]

My best friend/ brother, gave me a set of Dart tall aluminum valve covers! Now, just need to polish them up!!

[fbpd227]

Well, naturally, when your bro gives you a set of Dart aluminum valve covers, and then you find a listing on CL, for a set of Dart 308 aluminum Race Series heads, already fully ported, polished, and shaved, for $1500!!!!!!!! How could I say no!!!! These babies are beautiful!!! Who ever did the porting work on these rase series heads, deserves an award!!!! They have the 2.25 1.88 stainless valves, heart shaped combusting chambers, and the .300 raised exhaust ports, so should flow like crazy!!!
As far as I can tell, not knowing specifics about them yet, they appear to be similar to the Pro 1's, but according to Dart, they are not? Dart says they are made as ordered- bare castings, and the racer has to finish thrm....porting, building, etc... so many variables can change..... All I DO know, is I got them CHEAP, for what they're worth!!!!

[fbpd227]

Today, I got in contact with an old engine builder in FL, and we're working out a deal for something almost exactly like this (don't have any actual pics to post, yet, but this is almost identical!)

[fbpd227]

I LOVE the Predator carbs for ease of tuning, variable venturi, and running a little fatter, for safety of the motor! Lean spots suck, and can kilL a motor..... I found out the hard way! Planning on overy the transom stainless headers , possibly dry, depending on cam choice.....
Looking for the right hydraulic roller cam kit, for my set up. Also full roller rockers, stock ratio.... be humane to your valve train! LOL!
I know there are ALOT of very experienced engine builders, with ALOT more knowledge than, I, please feel free to offer input and sugestions! Good or bad, I take all info to heart, research, and go from there! I've put together many engines over my 47 years, mostly mud bogger in FL, but jet boats are another beast, and I'd rather learn from the experts now, before I waset ALOT of money!!!!!

[fbpd227]

OK! Now I can get some numbers out of these heads! Just got my "cc kit" from Jegs! Hopefully I can determine chamber, intake and exhaust volumes! May not know flow numbers, but at least knowing volumes helps alot!
If anyone has any sugestions, please feel free to comment, pm, or even text me at 864-305-6179. Thanks!!!

[fbpd227]

OK, now I got to get to work!!!!
My polishing kit arrived today, so time to stop posting, and get working!!!!
I'll post new pix as I make progress!

[FMP]

Just so you know that someone is listening, oh that poor jet pump isn't going to know what hit it.

[fbpd227]

:iagree:
:cheers:
Thanks, bud!

[fbpd227]

HOLY CRAPIOCA, buffing is hard work!! This crap takes forever!
Took me 4-5 hours to get one valve cover done, and it still needs a few more fine cut buffs, with the Tripoli ruge to really shine, but good Lord, my arms are whooped!!!! LOL!
My much better half thinks I'm crazy, but it's a labor of love!!
Probably wouldn't be as hard if the covers weren't so ruff from the sand cast!
Anyhow... here's a couple pix....
Back to the garage now.....

[fbpd227]

YAHOOOOOO!!! My stroker kit was delivered today!!!!
NOW, I can get all this crap over to the machine shop!!!!!
I sprayed down my crank with PB Blaster to keep it pretty until assembly..... humidity sucks in the south! LOL!
Now, gotta get this stuff into the right hands!!!!!

[fbpd227]

Double bonus!!!!!
Got my valve spring micrometer today too!!!!
Yeah!!! Gonna be a busy weekend now!

[fbpd227]

Well, got both valve covers polished! Bought a new air angle polisher and coarse, medium, and fine scotch pads- DEFFINATELY made the job easier!!! I may do the tops again, to erase any little pits/ scratches left, but the shine is there, now! Big improvement!

[fbpd227]

Ok, got the heads CC'd.... and got some interesting numbers.....
I'll cut to the chase,

compression chambers all ranged from 121-122 cc's

Intake runner volumes ranged from 251-253 cc's (much smaller volume than I had thought, but good for port velocity! )

Exhaust runner volumes ranged from 125- 130, with almost all at 126 or 127.

Sorry, couldn't get pix, since my hands were constantly wet, or greasy, or just plain dirty.... sorry.

The interesting thing with these heads is they have the heart shape open chambers, huge 2.25/ 1.88 valves, and in my opinion, very small intake runners ..... leading me to believe from Internet research, that they will keep high intake speeds, and coupled with a tunnel ram, hopefully will create a very good "ram effect", and with the large vslves, should scavenge pretty well....... I hope I'm right... the recomended can comes with long duration, and relatively high lift, so shouldn't the combination be pretty well matched? I know You never want intake runners too big- kills velocity, and you want the larger valves to displace more air volume, but my question is, with @ 252 cc intake runners, and the volume of the intake runners on a tunnel ram, do they "add together" for intake runner volume, and compliment each other in the combinstion, or is the 253cc head intake runner a "choke point"?
Any advise, input, or sugestions?

[fbpd227]

It seems to me, even though these are rectangular port heads, they actually compare a bit closer to the ovals?
Yes, no, maybe?

[fbpd227]

Well, got my two Predator carbs delivered, with the Moroso fuel regulator, and promptly ordered two complete overhaul kits for them. Super simple design, and very interested in the variable venturi aspect of them, in my combo. Going to be a learning curve, for sure. My nostalgic look and experiment, may fail, but I have to try first, before I change to more modern carbs. But, I DO hope they work great for me!
I fooled around for about 5 minutes on one, trying to polish it up some, and can see with alot more effort, they'll look pretty nice!!
OK, off to the lake today (pontoon day with wife n dogs- gotta keep the "garage widow" HAPPY!!!!!)345700345701345702345703345704345705

[fbpd227]

Ok, FINALLY found the machine/ speed shop for my project! !!
http://www.atlantaspeedshop.com/home-page.html
These guys do alot of hi-performance marine work, and engine building for professional racers!!!
It'll cost me more, but totally worth every penny, when it comes to the quality and pro experience they have! Every question I had was answered AND a ton more info, on things I hadn't even thought of yet!!!

Ok, moving on... I wanted my block to have a smoother look and "pop" a bit better once painted, so I prepped it tonight, so I can drop it off tomorrow, or Saturday.
I ground off all sharp edges, removed all casting flash, and smoothed out the oil return galleys for better drain back. Covered in metal pieces, but every things a small step towards the final reward!!!

[fbpd227]

A quick question..... my block has no head dowels, does that mean it's been decked, or shaved?
I was planning on 0 decking my block for a better "quench", but prepping the block, tonight, for the drop off, Is when I noticed the lack of dowels? Any input? Any way for me to check if it's been shaved?
The list of machine work is deep, that I plan on doing....
Vat dip, bore, torque plate hone, align bore, 0 deck block- .020 shave, cam bearings, clearance block for stroker kit, shave/ mill heads .020 to bump compression by -6cc's, and pin the rods. About $1400....
If I want to let then assemble the bottom end, about $585 more, whick, I'll probably do, since they will give a guarantee on the short block if they assemble.
So, 2 more boat "units" to get closer to my goal.
One more boat unit for the hyd. roller cam kit, so should get me pretty close to about $8K this far on the engine!
BBC, does NOT mean big block chevy, it means BIG BUCKS CHUMP!!!! LOL!

[fbpd227]

Ok, I'm still waiting on getting the engine block n stuff to the speed shop, since last Thursday morning, after I had loaded everything into my truck to drop off, while working in ATL, my tranny decided to dump at 5am on the way in, so had to limp it home and unload everything! Anyhow- still don't have my truck back, and as much as my much better half loves me and fully supports this project..... she said, "HE'LL NO"!! To trying to load everything into her LT- loaded, leather, etc.. Tahoe!!!
Should get my truck back tomorrow, Friday...I hope!!!
But!
In the mean time, I ran across another tunnel ram, and bought it, because it's already polished.....
But! Now I'm not sure if it's what I need? It's smaller on the open intake top, and the runners are not fully exposed to the air for a cooling charge effect... they're actually heated by the hot oil on the bottom side of the runners.
I have no problem doing or paying for polishing (probably DOING- for more hands on!) Of the other tunnel ram, my concern is more of keeping the BEST one for my build, and selling the other......
Ok.... pix time....
Let me know your thoughts, based on my build.....

[fbpd227]

Not much to update right now.... the engine is still at the machine shop being worked on, but I did pick up a nice small body Mallory magnetic breakerless distributor for the tunnel ram!
Hoping that it won't be too much longer to get the engine back!

[Tripps]

Nice job had a few jets keep goin