abc123

Hello guys, I have an odd project. I have avery nice 8.1 vortec engine
i want to get more powerful and a lot cleaner than it looks today.
i know its a step back to swap the fuelinj to carburator , but its clean
and the the carb intake flows more . it can end up with a tbi ho knows.
its going in a camaro 1970, th2004r trans 3.50 gear.
is there anyone at this forum that have made this kind of swap
with the new dart carburator intake , and perhaps the new 8.1 iron eagle
heads, ?? my plan is a more radical hyd roller , sanderson qp2000,s
aftermarket rods&pistons to keep it together. chrome oem style early
valvecovers, ... yea i am old , but still rodding
inputs are welcome

TyCZ28

Raylar kit... 450hp 500lbs/torque


http://www.raylarengine.com/kits.html

2 Stroke Racer

iTrader: (11)

That avalanche sounds awesome! I have an avalanche with a 8.1
Awesome truck. But Ive considered doing a few things.
Maybe a cam, headers??? I don't know a lot about raylar..

C5natie

iTrader: (1)

I would bring the compression up to about 12:1 on that 8.1L and with a nice cam itll be a real beast. Torque galore. Those 454's are pretty stout. A friend has one in his Surburban.

TyCZ28

the 8.1 is a 496 big block not a 454...

C5natie

iTrader: (1)

Woops, youre right. Its a bored out 454 I believe. 7.2L to 8.1L.

93Z2871805

iTrader: (5)

454 is 7.4. The 8.1 uses the same 4.250 bore as a 454 but uses a 4.37 stroke to get to 496 instead of the more conventional (4.310 x 4.250) stroker.

warriorcustoms

iTrader: (10)

The 496 is a mean ****** when built right Id find nice dart alum... heads to go with the intake & match the cam to the RPM range of the others Instead of a 200R4 Id go with a 4L80 youll need it with all that Torque Ported heads & everything port matched will help A Lot Prolly atleast a 850 for the street but if your gonna mostly race it then around a 1050 Depends on how tight your gonna wind it!!! CraigsList & RacingJunk always have some good deals on BBC alum... heads Ive found lots of stuff for my 396 LTx build off those sites Mostly nitrous stuff Hopefully my 2 cents helps LoL Ive been lookin for a plain jane 72 RS for a build After my current 2 projects

93Z2871805

iTrader: (5)

The only problem is the 8.1 is a Gen VII BBC and shares next to nothing with the older BBCs. I've only seen 2 or 3 companies who make parts for them (and the stuff isn't cheap either).

BrianEsser1976

x2

I wouldn't waste my time unless you know the limitations these motors have in aftermarket parts, or you have deep wallets. But, for the same money, you can make more gains with a conventional BBC build and have the vast aftermarket that comes with it.

jmd

iTrader: (4)

Price a few aftermarket Mk IV 496 longblock engines, then price the conversion parts for the late model 8100 and you'll see why you may want to stay old school.

ZONES89RS

iTrader: (25)

I wanted to do a BBC, unfortunatly when I found all the extra cost and lack of my ability to get my hands on a set of heads for a reasonable price, I swapped to the Carbed LS. Maybe I will do Bigger cubes one day, 427 or 440-454 LS, but I cannot justify the big block. Surely will never use a Sbc again.

I was looking at the newer gen bbc, and man, prices were horrible.

xx_ED_xx

iTrader: (17)

Owns five 8.1's and yes support is next to nil for the gen VII's

93Z2871805

iTrader: (5)

I hear this alot lately, however I've seen some pretty nasty BBC builds come together for around the same price as an LS build. As far as heads are concerned BBC stuff has come down in price (considering the latest LS boom it's no wonder), for instance, a set of AFR 245s retail for $2350(as cast)-$2700(competition) on an LS whereas a set of Brodix BB-1s complete with Ti retainers go for $2300 ($2500+ for BB-2s and BB-3s). BBC piston sets are $400-$1000, and LS piston sets go from $400-$900. I don't see the major cost difference on your average weekend warrior or a budget race car. My true street cars and DDs - LS all day. But if my goal involves 700+ hp and a mountain of torque with no regards to economy - BBC hands down.

xx_ED_xx

iTrader: (17)

Agreed no replacement for displacement ever

ZONES89RS

iTrader: (25)

Yea, I can say I agree. Unfortunatly I used junkyard LS and cam only, spin to the moon, still have to retro to roller on a bbc, replace a bunch of BS, headers selection for my car with a big block suck harder than I can explain, the list went on for me. I go with used parts and all the BBC stuff was still over prices or junk wen I got it.

The gen III an IV drops in easier as well. The LS bridges the gap between sbc and bbc I think when it comes down to budget. Now we have ls7 and 510 ci LS, I am thinking I would still not go bbc if I had cash falling out of my pocket. Lol.

93Z2871805

iTrader: (5)

Very true.

Depends on your goal. The BBC is the more cost effective option once you start getting to power levels above 700hp. I'd say anything under that level the LS would be the better option.

ten5nova

GM really missed the boat with the 8.1. Not much that can be done with it unfortunately. Unless you are happy with how they run stock. I saw one in a 70 Monte Carlo once. Really clean swap, but I doubt it was the nastiest thing of all time. It's a damn shame that early BBC heads will not work on the 8.1 shortblock. Everybody and their grandma would have an carbed 8.1 in something. Give the aftermarket enough time, there will be plent of parts for these things eventually. I doubt companies will ingore a factory 496 for too long.

bigdog7373

That's a lot of compression, especially for a carbed motor. I'd stop around 10:1

93Z2871805

iTrader: (5)

Hate to say it, but they've been ignoring them since 2001.