BBC build- Don't tell the Admiral

[Tail_Gunner]

Gen 4 old 454 mercruiser peanut heads, the boat above is good for 70 some reading material or food for thought. My main goal is a good response on throttle read sharp response.

http://garage.grumpysperformance.com...omparison.319/

http://www.cartechbooks.com/techtips...bigblockchevy/

 

[Scott Danforth]

Haven't posted in a bit on this project, the kitchen remodel has taken precedence.

Today scored big. Killer deal on NOS Corsa exhaust kit.


Still vascilating between 468 and 496. This article is using the air gap intake, cam, heads, etc that I am using. http://www.superchevy.com/how-to/eng...mple-cam-swap/

Would like to see dyno results of a bump in compression along with a 4.25" stroke.

That's all for tonight, going back to drywall dust

 

[Scott Danforth]

This project is starting back up. Kitchen remodel is done. Just picked up an airgap intake. http://mohave.craigslist.org/pts/5621301990.html, and an aluminum water pump http://mohave.craigslist.org/pts/5610248546.html.

Intake is a great deal, water pump will be if it's in good shape. If not, oh well.

Will also pull heads tonight

 

[Scott Danforth]

Come to the conclusion my boating dreams exceed my current wallet content. Need to get all new accessory brackets.

 

[Scott Danforth]

Parts...parts...parts....

I now own Mark IV oil pan that doesn't fit a gen 6 block. I also own a long water pump where I need a short water pump.





Now have parts on CL, and looking for the parts I need. Next thing to get my hands on are the SBC to BBC adapter brackets similar to the mail performance ones... http://www.kwikperf.com/bbc_serp_kit.html

 

[Scott Danforth]

Little update....

Received my air gap intake. had to sit it on the motor with the carb


(photos gone due to photobucket issue)

started taking the motor apart. pretty uneventful except for dropping a head on my knee as I whacked it with a dead blow to crack the head gasket loose. it did, head popped right off the dowels and onto my leg.

bores look good except for the rust trail where my degreasing episode 2 weeks ago got into the combustion chambers thru the spark plug holes. should have pulled the heads then. however it will be getting a bore and hone job anyway.



been trying to sell my Mark 4 cast oil pan for weeks. decided to see if I can modify it to fit the Gen IV.... a bit of cutting, a bit of grinding, and it will fit.

here is a write up on iboats http://forums.iboats.com/forum/engin...r-a-gen-iv-bbc

 

[Scott Danforth]

Finally a little time on the motor between chores. Spent most of the time working on the oil pan mod and looking for deals on parts on CL. Spent a bit of time making a list of the little chores such as blast and paint pulleys, etc.

 

[Scott Danforth]

A bit more progress....

just scored a set of Stainless Marine manifolds



for a bit more coin, i could have had either of these:




the later two came off a 750hp 540 with a supercharger..... dont think my little 496 would make enough HP to matter. If it did, my outdrive wouldnt survive.

 

[Scott Danforth]

Budget review where i am at

Sold original SBC for +$1300
Bought BBC core motor -$440 (included tax)
Bought low hour L29 heads -$150
bought Mark IV oil pan that I am modifying -$75
bought Air gap intake and long water pump -$260
Sold old L29 heads for +$250
So far, $625 ahead (with lots of parts watching for opportunities)

Things left to buy

New flywheel - $80 GM 3991469
New damper - $180
New scat forged rotating kit - $1798
new starter -$70
new alternator -$80
timing chain set -$125
Mehling Oilpump -$135
ARP head studs -$223
ARP main studs (for windage tray) -$170
Felpro gaskets -$125
Machine shop -$650

total estimate spend (not including cam) is -$3011. goal is to get this down to $2500

Cam and valve train are unknown right now. looking at a complete take-out Erson cam/lifters/rockers that came out of a 502 (same one my manifolds came off)

New comp cams kit will be

Still have a bunch of volvo SBC parts to get rid of - starter, fuel pump, distributor, etc.

Exhaust spend to date
corsa exhaust - (way too low to publish)
Stainless Manifolds with long risers - $550

 

[Scott Danforth]

playing with a desktop dyno program.

here is where the SBC was. (passes the smell test since the base was 271 hp and went up with vortecs and a cam). i drwe a line at 5100 RPM as that is all I could get out of it loaded in the boat.


Here is the 454 with the comp cam. matches pretty good with the article http://www.superchevy.com/how-to/eng...mple-cam-swap/ the dyno software is a bit liberal here by about 20hp



Here is the same cam, however stroked to 496 cubic inches. not much of an improvement shown, however I will be up from 9.4:1 to 10:1 and have a bit more displacement. 450hp should be within reach


here is the 496 with the Erson cam im looking at. the higher lift and slightly more duration push the power up a few hundred RPM


peak power gets pushed up, however I know the head flow starts dropping off at 5500 RPM. these are all with the current existing 715cfm carb. pretty sure I will need to re-jet slightly.

 

[Scott Danforth]

Working on selling my long-term project - 1973 Opel GT with a supercharged Northstar V8. dont have the room to finish it down here. selling that will finish the boat and get it painted

thru my searches on motors and parts, I have come across a pair of freshly built 509's one complete longblock, one shortblock. the long block has 4 dyno pulls, the shortblock has 8. motors were built however never put in the boat as the guy went 540 dart block build. If I sell my fresh 454 heads with my current shortblock.........

 

[Scott Danforth]

OK, so I have been offered a complete 509 short block and a set of heads that need new valve springs

the block is casting # 10237300 which is a Gen VI 502
New Eagle forged crank and rods
New Wiseco forged flat tops (single relief)
new roller lifters
HP500 cam

the heads are 14097088 castings (rectangular port, 110cc, non-vortec) with 2.25" intake and 1.88" exhaust. new comp cams rockers

dyno sheet shows 525hp at 5150 RPM with an MPI setup on it


I really like the idea of drop and go, however I already have a pile of parts for the motor.

fresh oval port L29 heads (99cc)
Air Gap intake (oval ports)
rotating kit

I looked into dropping the L29 heads on the 509 short block, however I would be at 10.53:1 CR. a little high for a boat.

Do I continue with what I have or buy the existing motor? part of me really wants to finish the 496 build, however a 509 would be drop and go. Admiral wants to hit me over the head with a cast-iron skillet because she just wants the boat finished.

Bondo , AllDodge ; Tail_Gunner , any thoughts on your end?

 

[garbageguy]

Working on selling my long-term project - 1973 Opel GT with a supercharged Northstar V8. ...

My Dad worked for Buick back in those days, and I can still remember cruising around with my Brother in an orange GT about this time of year. Later that year, I remember helping Dad get it out of the snow. Great memories, thanks for jarring them loose.

 

[alldodge]

Personally I would take the 509 over either the others, my opinion only, but more HP/TQ for the money. Now if you went the 509 way and used these manifolds and risers:

Then you will also need to get 3 inch taller risers due to reversion. I base this on the statement of 525 HP. Figuring this was done with dry headers on the dyno, you will probably have 515 or so once in the boat. This much HP will have a higher lift cam and you cannot use diverters unless you went to E-tops.

 

[Scott Danforth]

I couldnt use the selectable exhaust as is normally (short elbows and y-pipe) with the mufflers and long elbows. however I was thinking of cutting and welding, putting them at the transom, and either running straight out the transom, or out the side via mufflers and tips

the manifolds above were run for a few months on the motors when the motors were simply 502's and bravo drives on the boat. (same guy that I got the exhaust from). the long-tube elbow helps significantly with reversion (at least that is what the hype is on SMI's website. after he built the 509's he found a set of 540 dart blocks and built those for the boat. then blew the drives. after spending a fortune on new drives, he sold the boat.

he still has the 509's and will be listing them shortly if I dont pick the one up.

the 525hp was on the dyno, I need to follow up on which exhaust was on there during the pulls (I am also guessing dry headers). I will assume that would be in the 490-500 range at the prop with 525 at the flywheel and the manifolds above

 

[Scott Danforth]

thinking about exhaust layout in my head. thought I would sketch it out



with the long elbows, I have a much greater resistance to reversion based on everything I have learned in the past few weeks. the down side is the long risers are intended to go straight into the exhaust tips and out the back. the risers are about 24" long vs the standard elbows used with selectable exhaust

I thought of running like that - straight out the back with little flappers....the Admiral probably wont like that.....

so, the two ideas I have are to modify the existing diverters to a tip (bit of cutting, welding and polishing), then run thru the mufflers and side exits when I want to be quiet-ish and straight out the back when I'm by myself. this would eliminate the Y-pipe which I could sell on ebay for about $350

second idea is to cant the elbows outward a bit, rotate the diverters a bit, and use the existing y-pipe with a bit of modification and run thru the mufflers out the tip. this would be the quietest install and keep the peace with the admiral

 

[alldodge]

with the long elbows, I have a much greater resistance to reversion

Agree, but it's the down angle that gives the greatest reduction in reversion. Reversion happens at idle to 1100 rpm.

Nice ebay sell

 

[Scott Danforth]

Agree, but it's the down angle that gives the greatest reduction in reversion. Reversion happens at idle to 1100 rpm.

Nice ebay sell

there is about a 4" drop between the bottom of the elbow apex to the exit of the tubes at zero engine tilt so I should be good with the normal 5 degree rearward angle and also because I wont be going too radical on the cam. pretty sure nearly doubling the hp going into the drive may find the limit of something.

 

[Scott Danforth]

So, this project has been pushed to the back burner again. Wife wanted a distressed farm table since she watches too much HG TV. So after selling the perfectly good dining table, we picked up a used farm house table with 4 chairs and no extra leaf. Built a leaf, repaired the 2 dog chewed chairs, found a bench and end chairs, then the wife distressed it.



On to the hutch, then back to the boat

 

[JASinIL2006]

All you need is some shiplap siding on those walls, with maybe an old wagon wheel as a decoration, and you'd look just like you were on Fixer Uppers!