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Discussion Starter · #1 · (Edited)
Hello,
I have a 70 Chevelle with a pro built 496 that on the dyno with a 780 carb it made 600HP and 600Ft#s torque. I have converted it over to Accel DFI fuel injection with a 1200 CFM Throttle Body and it's running 48# injectors.

This is a 4 Spd car and has a dual disc clutch. The manual trans has been an issue on the street and specially at the drag strip. At the same time I convert this over to supercharger, I'm going to change over to a Turbo 400 automatic with trans brake and manual reverse valve body.

My plan is to blow it out to more like 1000HP (or 1200) with a V4X Supercharger from Vortech. I'm currently waiting for the brackets to arrive while stock piling parts for things like Hydro-Boost braking, moving the A/C compressor, and changing the Power Steering pump to remote reservior.

I also plan to use a water/alcohol injection system to control temperature and detonation.

I'm looking for other members that have already gone the Vortech or Pro Charger centrifugal Supercharger route on their Chevelle's that might be able to offer some good information. For things like tuning, pressure, and fuel choice, among other things like launch RPMs and tires.

I built this as a combination street car and drag racer running on mostly pump gas. I'm not even sure what sort of positive pressure I can look for from the V4X just yet either. In an effort to get more followers on this quest and to include other members I don't want to exclude the Pro Charger guys. I feel like the Vortech and the Pro Charger are similar and should both produce similar results.

Thanks for your input!
Mark

 

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I will kick this thread off with a question , are you planning on running the 48# injectors?
I think with your goal you would need at least 80# injectors, larger if running E85 But I have not jumped off into that EFI stuff yet.
I am friends with some guys that run a shop and all their fast stuff is supercharged or Turbo.
Holley Ram intakes are prevalent at the shop and E85 on just about everything, everything is fuel injected.

Well except for their 1957 2 door hard top that I built a carb (750 AFB) for. It has 4 speed and Lt1 aluminum headed engine, claimed 373 gears.
It is the slowest thing they have.

It would be nice if you can tune the fuel curves and timing curves yourself on a lap top.
I bet some will chime in on how to go about that.
I am not giving up on my carbs just yet.
 

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Hello,
I have a 70 Chevelle with a pro built 496 that on the dyno with a 780 carb it made 600HP and 600Ft#s torque. I have converted it over to Accel DFI fuel injection with a 1200 CFM Throttle Body and it's running 48# injectors.

This is a 4 Spd car and has a dual disc clutch. The manual trans has been an issue on the street and specially at the drag strip. At the same time I convert this over to supercharger, I'm going to change over to a Turbo 400 automatic with trans brake and manual reverse valve body.

My plan is to blow it out to more like 1000HP (or 1200) with a V4X Supercharger from Vortech. I'm currently waiting for the brackets to arrive while stock piling parts for things like Hydro-Boost braking, moving the A/C compressor, and changing the Power Steering pump to remote reservior.

I also plan to use a water/alcohol injection system to control temperature and detonation.

I'm looking for other members that have already gone the Vortech or Pro Charger centrifugal Supercharger route on their Chevelle's that might be able to offer some good information. For things like tuning, pressure, and fuel choice, among other things like launch RPMs and tires.

I built this as a combination street car and drag racer running on mostly pump gas. I'm not even sure what sort of positive pressure I can look for from the V4X just yet either. In an effort to get more followers on this quest and to include other members I don't want to exclude the Pro Charger guys. I feel like the Vortech and the Pro Charger are similar and should both produce similar results.

Thanks for your input!
Mark

What block and rotating assembly? Was ring gap and bearing clearances set up for a blower? Was the cam spec'd for a blower as the intake valve opening will need to be much later and the duration split will need to be at least 8 degrees more between intake and exhaust?

Blowers add a hole new dynamic to engines.
 

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is it a 2bolt main block? the caps wander around under boost :(
i'm on the 2nd block for this combo...
what are the cam spec's in the engine currently ? some work way better than others
mine was matched to the engine combo, it was a [straub] spec'd stik, it was the 4th cam for this combo...
you mention having efi with 48# injectors, you will need much larger [x2] to support your target hp wanted.
i switched from a 5speed tremec to an t400, it made the car easier to drive :)
i'm on my 2nd converter, it is matched to the drivetrain/car spec's
you are wise to ask for advise, so you do not find out the hard way on this.. >:)
 

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Discussion Starter · #5 ·
Shoot guys! Sorry for being so tardy. I put this up there and got busy on a bunch of projects.

I will have to go back and check on the ring gap. I have it. But, they were clearanced for medium compression + carb.
To answer your question;
NO it wasn't built as a blower motor and I'm trying to decide about pulling it out to make all the changes. Since I'm not going to go wild and hammer it or over drive it, I figure I'll get by and be able to do some testing before building a monster. However, if I was to get serious about it, I know it means pulling the engine out, changing the pistons and swapping the cam at the least.
I DO know that. I'm not a novice at these things. But, I'm also a realist.

"Speed cost money son, how fast do you want to go"

It is a well balanced and blueprinted professionally build engine from a racing engine builder. I had them build it fairly stout without going wild. It's got good components in there, not great. As in the crank isn't forged 4340 because I wasn't building a blower motor at the time. It is rated to 700 HP. The pistons are good forged units. The block was sonic checked, it wasn't over-bored, and the cam is suited more for the carburetor. I put a quick change timing cover on for easier cam swaps. I'm considering pulling the engine for these upgrades. (Pistons, Cam, Crank, and ???)

This is a good 2 bolt main 454 casting with all new ARP hardware all the way through it. The compression is 10.21. The cam in rough numbers is just over 600 lift and about @300 duration and a 110 center. It's got good aluminum heads with all roller setup. Comp roller lifters, and stainless 1.7 ratio rockers. The heads flow 330 on the intake side, so plenty large. I've got 2" Hooker headers and 3" stainless Pypes with X pipe and electric cutouts.

This was meant to be (and it is) a really fast, powerful, pump gas, street motor that sees time at the strip.

Really starting to sound like pulling the engine is the best way. (of course I knew that) I just seriously wanted to mount and play with this blower a little while just to see if it does what I want before I get super serious. Not being serious has already cost several thousand dollars just to get the thing on the darn engine. A grand ($1000) just for the cog gears, belt, and tensioner setup. Then mounts, and supercharger, plus blow off and tubing is really adding up.

Still I might be a total fool to throw caution to the wind and run it without doing more to the internals. I get it... :(

What I am looking for is advice on the compression ratio VS the boost and the Injector size plus Water/Methanol Injection to soften the possible detonation. I'm not sure I can use these pistons and get by without changing them going the route I'm trying to go. That is where the make it or break it, pull it or lose it, will come in, and why I'm putting this out there for all your hard fought and won advice. If the collective doesn't think I can safely play with this blower on my compression ratio and methanol injection, then it's time to pull it.

On that note, the reason I said I converted it to EFI was so you would know I also have detonation protection (knock sensor) and the electronic ability to hear it and pull timing out of the thing. Plus the water/methanol to cool and compensate for the higher compression and the possible heat. It is a "stoplight to stoplight" Drag Car. Not heading for Bull Run or the Daytona 500.

I read you are much better off going with lower compression and more boost, then higher compression and lower boost!
 

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Discussion Starter · #6 ·
Thank you for replying. You sound like one of the people I was hoping to hear from. Please locate my other more detailed reply. Yes, it is a 2 bolt main block.

I really want that easier to drive automatic. They are also a lot easier to launch at the drag strip. Plus shifting that regular 4 speed while going all out down the quarter mile is also a little nuts... LOL
Even that 2 disc clutch is a bitch on the street.

WOW, I can't believe you are really talking 2 times the injectors. Darn. I have been seriously looking at adding a second set and already have a 100# PSI fuel pump to put in front of my in tank pump so I can use a bunch of extra pressure and try to use that PSI with EFI to compensate. I am still thinking I need to bump up to about 60LB injectors at least.
I was thinking extra pressure, plus water/methanol, and being able to adjust the pulse on the injectors might do it.

My name is Mark. I'm @55 and a total car guys from birth. Retired automotive, have a whole shop in my garage. All the tools from a professional career as a mechanic and having auto repairs businesses along the way.
 

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I'm contemplating a supercharger as well. Not an inexpensive route, but when would four digit HP?

Comment about the injectors...believe folks are stating that 48# injectors are sufficient for 600 HP, if you shoot for 1200 HP...twice the current...you will need twice the injector-80 or even 120's...many are same price no matter the size. Fuel pump-same deal-sufficient capacity to fuel that HP number.

I'm disappointed you won't stick with the stick...much more exciting!

Good Luck!
 

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I would just buy 120lb injectors ( I only buy from FIC and have never ever had a problem and great price) , get familiar with your efi setup (tuning software), sure you will need a map sensor upgrade. Extreme velocity is only hat I'd ever use and recommend.
Worth it to atleast swap pistons and cam, good rods if you don't have them, rebalance.

At 10.2 even with water/meth ( trust me you'll end up running 100%meth, water doesn't fight detonation near as good, I don't bother with HEAT, I buy VP methanol, cheap and pure) you are going to fight getting any timing in the motor. (Timing is power) . Tuning with meth is important and you will end up trying different nozzle sizes , possibly multiple ones, remember meth is "fuel", your tune will reflect that.

Get compression down to 9:1. Lower if non-intercooler.

Custom cam recommended , also possibly need valve spring upgrade. ( boost pushes on back of valve) .


All in all I say try 6-8 lbs before you think 1000hp, work your car and your tune up to it. I have no experience with accell dfi or tuning software , I prefer Holley Efi.

P.s. No chambered mufflers !!!

Most tuning is done with a set fuel pressure by the way , 43.5psi. Boost reference changes that on its own. I would not recommend crutching small injectors with increased fuel pressure , will only make tuning more of a headache, just buy good injectors , not much in grand scheme and will save your motor.
 

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Discussion Starter · #9 ·
Great advice guys! Thank you. I suppose I should start pulling the trigger on a few other parts and pulling the engine.
When I put in the 48# injectors I thought I was going on the high side of things. Hard to believe I'll be buying 120# soon. That is really huge. Hey, at least I won't have to worry about being lean... Really sound advice "hereinmissoula" you do want things to be consistent when you are trying to dial in EFI stuff. Those race mufflers I've got are straight through 3". BTW: I already bought the new MAP Sensor. I've been prepping to run this thing...

The extra pressure was a long shot to running this in the car prematurely. I'm currently running a really good in tank pump that puts out a consistent 43.5 psi. I actually noticed it was dropping the pressure a bit and had a conversation with a guy about wiring. Needless to say, if you want that pump to be to keep up under a load you need really good stout ground and large gauge wire feeding the pump. Mine was weak and once I put in the right wiring it straightened right out.

I was already wondering if I just convert the car over to methanol if I can avoid the pistons. It's got great rods and all ARP hardware. It has a good set of Diamond pistons, I believe. The weaker end of it is the crank not being forged and the block only having 2 bolt mains. I was really trying to get more time out of the money I spent to build this engine without making a big lower end change. Just like you brought up, it means re-balancing everything and starting all over again. I was planning to get a Big M block and go bigger cubes later. Instead of putting a lot more money into this one. Because as one of the other guys pointed out, this is a 2 bolt block and it won't hold the big numbers.

At this point, I'm starting to see the error of my ways and thinking the blower should wait. I'll look at building the next engine for the blower and that way I can run this one for a while longer. I might even be able to sell if for the money to buy the lower end parts.
Shoot!
I suppose I should thank you ALL for setting me straight and keeping it real. This was a long shot at best and you've talked me back down to reality. I might just set the blower aside and run this car another season like it is. I was starting to get it dialed in and she was making good passes. There are a few other things I've been upgrading and changing too. "She really turns heads and sounds like a BEAST at a stop light" At our age I'm not afraid to turn it loose in front a few people when the cops aren't around. My neighbor is a cop and he just drools over it. LOL :)

Who is "FIC" for the injectors? I don't recognize the vendor. I always like to find new vendors with good parts at a good price. I think I paid close to $400 for my last set. I can't imagine what the 120's will cost.

I wish I could figure out how to reply to the person individually. Each of the people that have comment have had some great advice and things to say. It's hard for me to say that in one reply to several people.

Really glad I posted here and asked you guys!
 

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I`m no expert so take this with a grain of salt.
Also a bit late to the party so sorry if this has already been covered. But why not just relax a bit on the 1000hp goal. Try running just a few psi, I`m sure it will still be a different animal even with a mild tuning. If it pings just dial back the boost, or go real conservative on timing and fuel, or mix in/run a better fuel for the track.
Maybe open up the engine, and adjust it some.
Give it some more piston ring clearance, maybe shave some material off the pistons, unshroud the valves some, and maybe 0.10" thicker head gasket (I`ve heard - not experienced - that quench is not that important with boost). Just using a different head gasket, running a 0.049"quench instead of 0.039 will move compression from 10.2:1 to around 10:1, taking 1cc off the chamber around the valves, and milling the pistons 1cc will get you around 9.85:1 cr. If you have a domed piston.
If you can do 2cc pistons and 2cc chambers you`re at 9.7:1 cr. That`s starting to look like boost territory on the cheap to me. Even just doing the heads 2cc and head gasket 10cc will give around 12cc and get your cr from 10.21:1 to 9.86:1.

Something to keep in mind. Not saying it`s a recipe for a trouble free life, but trying to give some food for thought.
 

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Yeah you don't need much psi to make a big difference when you're starting off with a 600hp engine. Figure 5-6psi is like driving around with a never ending 200 shot of nitrous :)
 

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FIC = fuel injector clinic

Individually flowed , great price , never a problem , good service. Other great companies , just who I've always used , imports to ls's. Never had a prob.


4 bolt block of some kind and a forged crank/lower compression Pistons a much better idea. Might be on a time bomb otherwise . Forgivability on your tune will be low with your current setup.
 

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Lots of interesting advice here from people not running blowers, no offence but not real accurate.

You are going to learn that a NA engine will not live at 1000hp with boost very long. While it may sound like you have great parts, the are not for a boosted app. I had a motor built for NA, all top name parts, made good power. Put the procharger on and it all changed.

I took last year off to redo the motor for boost after I suffered pushrod flex (they were perfect for NA, not so much boosted) which caused all kinds of damage. I put about $4k in valvetrain upgrades alone (Morel 903 lifters, jesel shaft rockers, Smith Bros pushrods, block labor, etc)

Unless you are running E85 you should think about some kind of intercooler. I went all out with a W/A just to be safe. I don't spray meth.

Oh and your headers are also on the small side for your power, plan on 3.5 to 4in exhaust. Then there is the convertor and rear gear for boost which is different than NA and then upgrade suspension, and on and on LOL

Don't me wrong boost is awesome but its hard on stuff.

Straub asks perfect questions!
 
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