[Derek69SS]

I'm nowhere close to being ready to start this project, but just thinking about it and getting ideas.

I want to build my '69 SS to run like the guys in the F.A.S.T. class, although not competitively, (not even stick to their rules - just build a fast car that looks stock) and keep the car somewhat streetable. Although it's not an L78, I would make it "look" like one, it would also have a muncie 4-speed.

The only constraint is there would be no visible modifications. It would have to run an L78 intake, correct looking carb, and correct looking air-cleaner. The valvetrain would have to fit under stock appearing valvecovers, and it would have cast-iron manifolds with stock exhaust (chambered was available in '69 ) It would need to "sound" stock at idle. Tires would be 7" bias-plies from Coker, and all the suspension would have to look "stock", right down to the spiral shocks.

Anything else goes What would be your recipe?

 

[GM PARTS1]

A 496 or 540. Bigger motors don't need radical cams to make grunt

 

[mr 4 speed]

A 9 to 1 compression 496/505,oval port heads 2.19/1.88 valves and a 288/296 Voodoo hydraulic roller

..and I like the way you think..I've thought of this route plenty of times with my car.Even if I left the headers but added the Polyglas GT's

 

[Busted Knuckles]

I don't think you'll be able to use the extra grunt that you'd get with a big bore stroker, so I'd have to go with the 502. The bigger bore will unshroud valves and be worth more at all rpm's than a stroked stock/smaller bore. Oval port heads with big valves, bowl work and a hydraulic roller around 230/236 with .600 or so lift on a 112LSA would idle very close to bone stock thanks to the cubes you get from the bigger bore. An 850dp could feed this one to 6500 with the right valvetrain and that's where you'd run into trouble with the bigger bore stroker - feeding it at higher rpm's. Other than fuel injection, there's not a lot available short of a 4500 carb for the bigger strokers. You could probably get away with a solid roller in this application, just decide for yourself how much you want to wrench on it. I've got one very similar to this that I think I'm going to put into my 1-ton with a size bigger cam (HR 236/244, .615/.615 on a 112) because I want it to bark a bit at idle. I think that 502's get a bad rap with regards to power because Chevy builds 'em with small cams and low compression. They'll really wake up and growl with the right heads and cam. My .02

 

[Chris_69_SS]

How fast do you want to run? Will you use slicks?

Nothing wrong with a good 'ol 454 if low 11's are the plan!

 

[Derek69SS]

How fast do you want to run? Will you use slicks?

As fast as I can through stock exhaust and on 7" Cokers.... I'd probably try it on slicks just to see what it's true potential is, but I think it would be more fun to see what I can achieve on the Goodyear Polyglass's

I guess to me it's more about the challenge than the actual performance. I want the car to be able to go right from the 1000 point judged show to the track and knock down a high 11 or something crazy like that.

The F.A.S.T. guys are breaking into the 10s now, on "stock" tires but I don't have the time or money they have.

 

[cstraub]

I would build a 479 CID. On a 7" tire you can't plant the torque of a big stroke engine. I would get a 502 block and put a 427 Crank in it. This way you don't need an aftermarket pan to control the windage of the added stroke. This way in a 4 speed car you can get the car launched without it going up in smoke and once she's rolling then "roll into" the pedal.

 

[Dan Orgill]

Derek, some real good ideas here. I would think about a GM 454 crate. You would have the aluminum high rise intake right there brand new, and just bolt on the rest. You could probably do a cam swap to something a little more aggressive than what they give you, and still sound close to " stock ".

 

[GOSFAST]

We have 2 units in the door last week. I can tell you this, someone said to me recently "wow!", now I'll have a chance to race on my budget. Well, you can just "blow" that theory right out the window. The first thing we recommend is don't pick ANY unit that didn't come from G.M. with an aluminum intake or "Holley" carb, or you'll waste much money. We just tested a Pontiac (a "stroker" on a 455" base unit, Hyd. Roller, but we didn't build this one) all original appearing, including the Q-jet carb and it came off at 450 HP and 540 Ft.Lbs. Torque. I've been contacted about doing a couple LS-6 units, but chasing HP numbers. As I said, if you start with something that had some decent components you can use that as a "launch pad" so to speak. On the reverse side however, it will lock you into maybe a specific car for your choice. In simple terms, if you come in with something along the the lines of the '72 LS-5 Chevelle we just built, we would tell you not to waste your time or money on that particular one. Years ago we've gotten much experience with ONLY factory parts, as that was what we worked on most times. I'm in the process now of going back over old dyno sheets for comparison purposes. I'm not sure yet of all the class rules, but I believe "Bow-Tie" blocks and the likes wont fly here. I couldn't use so much as "double-thick" valve cover gaskets on the LS-5 we just delivered. You'd be looking at massive work done out at "Extrude-Hone" for these units. Thanks, Gary in N.Y.
P.S. The idea behind this new class is "kill" all the low end torque to get off the line, so the tires work somewhat, but make it all happen upstairs. Just possibly this may change the entire "theory" about intake runners that are too big normally, but will be ideal for this application. Again, you have to stay with ALL factory appearing items as they came on the car. Inside, however, anything goes! You'd be surprised how much work it takes to fit "low" G.M. valve covers with decent roller rockers. The rockers clear OK, but the (exhaust) poly-locks are the issue. The Vette with the brake booster could be another entire issue. These are what we consider "high-dollar" units. Of the 2 here this week, one is sold and one is still pending.

 

[Slowpoke70]

Biggest bore you can find and a 427 crank. Like a 427 except BIG.

Extrude-hone the manifolds.

Underneath-the-manifold Nitrous system?

 

[Derek69SS]

GOSFAST: great info, but I don't intend to actually compete in any class. I just want to do a similar build and see what I can pull off. There will be no "rules" I'll have to stick to, so a "wrong" block and a little extra height on the valvecover isn't an issue as long as it passes a visual inspection without getting out the tape-measure, a flashlight, and a book listing casting numbers to see if anything isn't "stock".

Most importantly, I don't want a trailer-queen, so 4.88 gears aren't in my future either.

 

[Motorhead62]

At the "LoneStar Nationals" Good-Guys event this year I was parked next to a guy with a '66 300 Chevelle with a 496/6-speed combo that blew me away. The car looked like a stone stock 396/4-speed.

The car was pristine and gorgeous and looked 100% original at first glance. He mentioned that the engine pulled 590HP or so on the dyno.

There is a thought for you! :beers:

 

[plain 69]

Your going the same route I am going. I presently have a 454 bored .030 but I am thinking about building a 540 cube motor in the future. I can use the top half off my 454 (049 with 2.19-1.88's). The cubic inches alone should get it down the road pretty good with a 3.36 gear. I would think with slicks it would get close to mid or high 11's or so. Coker reproduction tires should leave lots of black marks on the 1 to 2nd shift and maybe even on the 2nd to 3rd shift with the Turbo 400 trans.

I want the smooth stock idle as well. I just wonder how much cam you can put in and still have a smooth idle to pull down 14" of vacuum or more? Should just need a stock torque converter for that engine.

I know I am using the stock exhaust manifolds as well. I don't think most people that come to a cruise in will know that they are looking at a Dart or Merlin block.

I know you can purchase the Dart Blocks or Merlins with the 4.5" bore but what quality crankshaft and rods would you use? Scat, Eagle? I want would no more than 9.5 to 1 compression ratio. My heads have been milled down to 116 cc's. I don't think I will be spinning more than 6000 even at the track. I would probably shift around 5000 to 5500 rpms anyways like I do with the 454 I have now. Rarely would I go to 6000.

 

[73guna]

This what inspired me to make a stock looking 489.

http://www.chevelles.com/forums/showthread.php?t=36910

 

[Bob West]

Did ben70 ever get to the track with that motor? I don't recall seeing performance stats

 

[cobra2411]

My thoughts would be to work on the heads and use a solid roller so you can get more lift without adding duration. If I understand it right, duration and overlap affect your idle, so if you can stay close to the L78 cam with more lift and more agressive lobes you should be good...

As for the engine, go big! 496 at least. I saw a 67 or 68 Impala once that had what looked like a stone stock 325hp 396. Even had painted valve covers. Car was correct down to the calk marks. Then the guy took out a bunch of low 11, high 10 second time slips. He said he was running small slicks at the track (26x8 maybe, can't remember). He had a TH400 with a 3.31 12-bolt. He just kept grinning when everyone asked what it really was... Finally he said "add at least 100ci to it and you'll know what it is..."

It was cool and I would have never thought it was that fast. I'd love to know what he did to it...

David

 

[dyno jonn]

A 540/565 big block can stand a lot more cam than you normally think of and still idle quite nicely at 750-800 rpm. You can also use higher static compression with a larger cam that blows down a little on overlap. Some of the 600+ inch NSCA cars sound pretty tame, till they get on the loud pedal. :thumbsup: