Let's Build a Period Correct 283/6-71 Low-Buck Street/Strip Motor

Been dealing with some health issues over the holidays, but I am itching to get back to work on the '62 Corvair drag car project.
http://www.jalopyjournal.com/forum/showthread.php?t=542558
I have a line on a 283 in a friends rusted out '66 pickup. I also have a 6-71 straight off a diesel on a shelf in the garage. I am assuming the 283 will need rebuilding. I also have a couple other sets of heads, including some '58-ish 2 bbl heads, and power pacs from a '57. I know the 6-71 will need new seals/bearings, etc. I want to run v-belts if it doesn't cost too much. I have access to machine equipment. Also have a Spalding Flamethrower distributor. Let's do some bench racing!

 

You could always come up and get that Y block I have on the stand.

 

Done! But let's do a 283 also.

 

The guy that will be a huge help on this subject is Tudor here on the HAMB. Josh knows a shit ton about blown 283's and could definitely be a source for info on this.

I love where you're going with it and that 6-71 is going to be the shit!!! I wish I knew more about internals so that I could point you in the right direction but that's why I make friends with guys like Josh aka Tudor. He knows way more then I will and he does it right.

Now I am not sure the 57 power packs heads are going to be an improvement over the '66 heads but it's worth looking into. I think no matter what you're going to need some work done to them anyways so that's where more knowledgeable people come into play.

Those '57 PP heads can be sold for some of the rebuild on the '66 engine so you have some funds to play with. I think those heads could fetch $500 maybe.

You know me, I am interested to see this all come together. Stoked is more like it!!!!

 

I'm not interested in selling the heads, a buddy gave them to me(he still has them in fact). I was just thinking the older stagger-bolt valve covers(I have a few sets of finned aluminum with no holes in them) would look really good.

 

Here's a series of articles that gives a quick overview of rebuilding a used GMC 6-71.

http://www.project33.com/category.cfm?Category=Engine

Steve

 

I'm checking in Tricky Dick so I can keep track of this! Sounds like fun!

Mikey the P

 

Fair enough, I'd keep them too haha!! I bet someone who knew their shit could tell you whether or not those heads would work well on the 283 you have. Might be a chance to really wake that engine up with some tricks. The fact that you can run staggered VC's is icing on the cake!

Have you been looking at Chuckle's garage Strange Bird for inspiration? that thing is pretty killer.

 

Yeah, Scotty's Nailhead-powered Falcon is the shit...

 

Thanks Steve, I have seen that article, it made me confident I can rebuild mine.

 

I am on the Ravenel bridge I Charleston all week so this will be short. Need to get the compression to 8.5 to 1, you can use dished pistons or big cc heads. I had 76cc heads on my 283. And it was in the 7.5 to 1 range. Not a full race engine. I was also not worried about someone looking at my heads and making comments. You should double key the crank and run a crank hub for the pulley. Then just need to set up your advance curve for something like 18 initial 34 total all in by 2500 to 2800 rpm. With a 671 I'd start 10 percent under driven and see what kind of boost it makes. Get a msd btm if you are going to run on street so it'll pull timing out with boost on the top end. Then build the rest of the engine best as you can afford. Readf PGanhals steet supercharging book.

 

I used a summit 1102 camshaft in mine. It worked nice I think it was on 112 and had a little more exhaust duration than intake duration. Most blower turbo cams have about 10 degrees more exhaust duration. The blower will push the charge in

 

gas or alky?

street/strip or full race?

is a 66 283 big journal or small journal? Forged crank or cast?

 

Make sure you dont rely on the stock press fit for the dampener/crank hub.
I remember a local O.T '70's Camaro with a blown 283 that, on the 2 occasions I saw it at the track, spit the dampener off in the water box!

^ All factory 283's were small journal...although, I guess you could run a lg journal 302 crank in a 305 block and come up with something close.

 

oops! I'm thinking of 327's

 

I'm excited to see where this thread goes, especially if it's anything as in depth as Bass' stroker 265 build.

If you're looking for V-belt blower stuff, contact Rick Dean Blowers in Washington. The shop number is (360) 451-2119. A few other hambers have gotten some really nice stuff from him. Maybe they can chime in on this thread.

 

Whoa whoa whoa! Low buck! Gasoline, street/strip, whatever parts I can scrounge up in mine or my buddies' garages, a little HAMB classified shopping here and there and MAYBE SOME Ebay if finances permit. DEFINITELTY homemade shit whenever possible! Nothing exotic like 302 cranks and whatnot. Maybe these shitty heads are the ticket to the low compression I need?
http://www.jalopyjournal.com/forum/showthread.php?t=268086&highlight=heads

 

Any heads will work because it is forced induction. Still, The better the heads the better the power. It just depend on how you are going to get the compression ratio right. Old heads with small combustion chambers will require dished pistons. You really want low buck? Get a long block 350 from advance, slap your blower on and go race. Dress it up with finned vc or whatever. Other than that tell us your plan to build the 283.

 

The words "6-71" and "low buck" used together confuse me..

 

What are you planning on doing for a blower manifold? Modifying a 4 barrel intake? It's nice to hear you're on the mend and getting back into your project(s)

 

the reason I asked about alky, is BECAUSE I'm thinking low buck.

I'm thinking sealed power flattops, zero deck, .040" head gasket, the 6-71, and E-85

E-85 is cheap, and it'll help keep the blower cool on the street, but you need the compression to make it happy. It also has a high octane rating (105 ish) so it'll be detonation resistant, and with the zero deck and .040" gasket your quench is on target, which also helps with detonation.

good crank and rods, pay attention to your clearances, keep your R's in the stratosphere, you should have a solid, reliable, repeatable, and FUN little screamer

 

I've only seen E-85 once a hundred miles from here, so that's not really an option. I'll have to use stock crank and rods as well; this may not be do-able on a budget.

 

are your stock crank and rods cast or forged?

ok, forget the E-85.

cc your chambers and figure out where you need to be to run pump gas

"on a budget" just means "low rpm"

you can stick a blower on a STOCK 283, just keep the drive ratio down and don't floor it!

 

Not sure, it's still in a '66 pickup at a friend's house.

 

I'm not as old as some of you guys (59), but I don't ever remember a 6-71 as a period piece on a 283 when I was a kid. Smaller blowers like the 4-53 yes, but not the 6-71 (on a 283 anyhow).

Am I wrong? Does sound like a neat project, though.

Alan

 

What I read is that with low boost, say 7 pounds and under, and otherwise mild cam and heads, you're fine with stock rods and crank. I'm sure I'll be corrected if this is wrong.

 

I'm considering a 6-71 on a SJ 327 and the issues are similar to the 283. I have heard back in the day the crank snout was an issue. I don't think I would even consider anything cast in this build. Even with low boost figures I'd say a forged crank and pistons are a must. It might not be period but use a good aftermarket balancer with a bolt. Maybe a steel hub would be more period. Just cheap insurance relatively speaking.

 

I used cast crank and pistons in my 283. Yes it was a cast 283 crank. That is where managing the timing with a BTM to prevent knocking becomes important. My 4-71 made around 8-9 lbs at WOT running it 1:1 on the pulleys. I used a billet SFI balancer and tapped the end of the crank for the bolt. I would do my best to either add a second key or install a pin through the balancer to the crank to aid in keeping the balancer from spinning.

We kind of RPMs do you want to turn?

 

Not sure what a "BTM" is. I found some v-belt pulleys, I need to find out what kind of boost numbers they will make for a given RPM before I buy them. Is adding a key or pin to the crank something that can be done at home on a medium sized knee-type milling machine? I think my Millrite has a 32" table.

 

Boost Timing Management. Look on the BDS website. They have a chart that will show the anticipated boost for a given blower size at a certain ratio on a certain size engine. They don't have a 283, but you can use the 327 and interpolate the numbers a little.

Here is a 283 with a 4-71 with all cast stuff, and a single keyed crank - http://www.youtube.com/watch?v=IZgs_-RJrZc


The boost the pulleys will make is dependent on their diameters. If they are the same diamters they will spin the blower at the same RPM as the crank. If the upper one is smaller, it will spin the blower faster than the crank (over driven) or visa versa - Under driven by 10% or whatever the difference is.