Why wasn't the op scolded for not having a FSM? Seriously,enjoy YOUR car, and grow a thick skin! Welcome.Get some more gear in the car,there's a 391 SG on facebook right now in FL for $400. Not Mine.
Budget conscious Performance Upgrades
- Thread starter mavwreck
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Some Car Guy
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If the engine is running fine, I don’t see a tear down being a good investment with this budget. Just spray it and enjoy your car. Go pulling the engine and you’ll lose all kinds of time behind the wheel. You can get a kit and also optimize the fuel system for it and have plenty of cash for gas all season long. Maybe lose one weekend of work and then do some track testing. I’d also go first and baseline the car at your current elevation.
I’m not reading all six pages, plus the drama it sounds like went with it. So I’ll ask what rom are you turning when you shift? That carb is a bottleneck, well the 516s are too, still going to need a bigger carb if you want it to really go. You have freed up the intake and exhaust tracts. The factory put a 750 on the hp engines with less intake and exhaust potential, then went to 1000 cfm equivalent with the six packs. They didn’t change the cam specs, heads, or exhaust and claimed 15 hp. A lot of guys preach small carbs, but that’s for your diet. Ma Mopar knew what to do.
I’m not reading all six pages, plus the drama it sounds like went with it. So I’ll ask what rom are you turning when you shift? That carb is a bottleneck, well the 516s are too, still going to need a bigger carb if you want it to really go. You have freed up the intake and exhaust tracts. The factory put a 750 on the hp engines with less intake and exhaust potential, then went to 1000 cfm equivalent with the six packs. They didn’t change the cam specs, heads, or exhaust and claimed 15 hp. A lot of guys preach small carbs, but that’s for your diet. Ma Mopar knew what to do.
451Mopar
Well-Known Member
I'm too cheap to run nitrous. Refills can get expensive and depending on power level each run could cost $10-$20 or more in nitrous cost alone.
Most of the racers also carry extra bottles and bottle heaters adding to the total cost.
I could be off on prices, been out of the racing stuff for 10+ years, so like to hear what everyone is paying for nitrous per pound, and how much it costs per 1/4 mile run at different power levels?
Most of the racers also carry extra bottles and bottle heaters adding to the total cost.
I could be off on prices, been out of the racing stuff for 10+ years, so like to hear what everyone is paying for nitrous per pound, and how much it costs per 1/4 mile run at different power levels?
mavwreck
Well-Known Member
Well not sure if this is much of an improvement but I couldn’t pass up this deal! $100 for 1970 440 HP pistons, new set of rings and what I’ve been told was a set of mildly ported 906 heads. That last claim I’m pretty sure is untrue but the ports ARE really smooth so I believe they could at least have had a flap wheel run through them at some point
mavwreck
Well-Known Member
Right now I’m shifting at 4900 due to the wet spaghetti noodles some people refer to as stock style valve springs. Anything past 5100 I get valve float. As for the carb it was what I had that was tuned at the time and have wanted to switch to an 850 for a while.
hofferwood
Well-Known Member
4 of them seem to be missing those things-------ya know those things that hook the piston to the crankshaft--------yeah those things------wadddayacallem-----lol
I'm having a hard time seeing how those dished pistons will improve the compression..
PRHeads
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Before I got real excited about the compression bump, I’d measure the C/H of those pistons, and cc the dish.
See how much of a change it will really be.
From what I recall, the 68/69 440 factory flat tops would provide the best CR increase(if you’re looking to swap in used factory pistons).
See how much of a change it will really be.
From what I recall, the 68/69 440 factory flat tops would provide the best CR increase(if you’re looking to swap in used factory pistons).
padam
Well-Known Member
You could always mill .100” off the 906’s. Thats the cheapest way to raise your compression a point.
I did it and knocked a second off my 1/4 mile times.
Now, I don’t recommend it because it throws all other kind of stuff out of whack.
But since you don’t seem interested in really good advice I wanted to throw it out there.
I did it and knocked a second off my 1/4 mile times.
Now, I don’t recommend it because it throws all other kind of stuff out of whack.
But since you don’t seem interested in really good advice I wanted to throw it out there.
I believe the last one I took apart was about .055 down. Not far off a six pack piston
mavwreck
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My pistons are .125-.127 in the hole so the increase would be there but not as much. Might make good paperweights from the sounds of it
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That is really rude but funny as heck.
Hey… I AM Guilty of the same habits as the OP.
Sometimes I get good advice but am not ready to go that way. Some of us like a challenge, some are short on cash and looking for really cheap and easy stuff to try.
I applaud the OP for being a young guy with the same spirit that us older dudes have for this hobby.
Guys that dare to try new things sometimes stumble onto a winning combination. I’d rather be THAT guy rather than a pompous assclown that knows everything yet never has been seen doing anything.
padam
Well-Known Member
I didn’t mean it rude, but the OP is ignoring advice from some really smart guys, and I’m not referring to myself.
Now that I think about it,that was the cheapest, most effective performance upgrade I ever did. I am a tool and die maker, so I did some machining and made stuff that the average guy would have to buy or pay someone to do. I’d hate to total the thousands spent trying to get another second off my ET.
The reason it was necessary? The machine shop I trusted to order 10:1 pistons got me about 8.5:1 pistons, and I didn’t know enough to check it when I put the engine together. I was about the OPs age at the time and just didn’t know any better. (No internet then, remember?)
My point is that if you don’t start out with the correct foundation, you will have to do silly expensive things later to achieve your goal.
Some Car Guy
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The 906 cores for 100 bucks isn’t a terrible outcome.
Try and find the old MP porting templates and you could mess around with that part yourself.
Get a valve job done and give them a spin.
Try and find the old MP porting templates and you could mess around with that part yourself.
Get a valve job done and give them a spin.
PRHeads
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While the 70-71 6bbl piston is about .030” taller than the 68-69 flat top, the 4 valve pockets they have uses up that added height……..so the CR between the two is the same.
mavwreck
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While I wouldn’t say I’m ignoring good advice I would say it was foolish of me to pick up those parts. There’s over 100 replies to this thread and for me at least there’s quite a bit to digest and consider. Sure some of that is drama but I’m aware that there’s a lot of good advice to consider. I have yet to map out a solid plan and am putting together one still. I’m still young and ignorant so it should be said that I’ve still got a lot of learning to do. I’m still taking in all that has been said and the things I don’t quite understand I still have to learn more about and consider. Either way it’s good to hear most of everyone’s opinions and consider my options PRIOR to starting to tear into it rather than after I have it all blown apart. Hate to have my car in a million pieces then be stuck having to do certain things that won’t hardly do anything and waste time. I’m just trying to get as much info as I can before I start and made a poor choice, willing to admit that for sure.
BSB67
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Reach out to the group before an impulse buy. You’re not going to come across a once in a lifetime deal.
padam
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We’ve all been there and done that. The great thing about this forum is the practical info is unmatched.
I just bought a bunch of NOS performance parts that I really don’t know what they are yet. Hopefully there is some stuff I can use, and some stuff I can sell. That’s one way to support your habit on a budget.
As a weird coincidence, it was the auction of the same shop that I think I used to mill my heads (or manifold) back in the 90’s.
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