Aftermarket Horsepower?

[Buckskin7T7V]

A re-curving kit is a set of heavier distributor weights and various weight springs. The best method is to take the distributor to a engine shop and have them re-curve the ignition on their distributor timing machine. Tell them when you want the full advance to kick in, and let them dial it in for you. Then you re-install the distributor back into the motor and set the initial timing in with a timing light.

 

[GerryLP]

Its tough to gain significant horsepower by changing one component. IMHO, the internal engine components affords the best matching (more components that lends themselves for matching) for the targetted or desired horsepower.

 

[Jack]

Jack, You mentioned adding a recurve kit as a cheap way to improve performance. Do you have any suggestions on where one can be ordered? This is something that I am interested in trying. Thanks.

I agree with Buckskin7T7V ... the best way is to take your dist to a shop that has "SUN" distributor machine ... give em your pertinent info & desires ... let them curve it. But those machines are not nearly so prevalent as they once were ... nor are the folks that know how to use em. So, if you can't or won't go that route ... there's other options.

But first, before you do anything ... read up on it ... there are VERY good articles right here at CAC in our "free" knowledge base ... two authored by Lars Grimsrud (CAC member Lars) are:

http://www.corvetteactioncenter.com/kb/question.php?qstId=447

http://www.corvetteactioncenter.com/kb/question.php?qstId=435

lars.grimsrud@lmco.com

Lars used to offer a kit comprised of a vac can & some springs ... chosen just for vette performance ... for about $40 ... try him & see if he still offers same.

OR ... go to your local NAPA store and get a new "Vacuum Advance Control" (vac can) that has a better performance spec ... for an HEI distributor, a good choice is NAPA P/N ECHVC1838. Also for HEI ... while you're there, ask for a "Distributor Advance HEI Curve Kit" (weights & springs) ... such as NAPA P/N BK7354957 ... or NAPA P/N BK7354958 ... or ... Mr. Gasket P/N 929G ... any of those sets will include 3 pairs of springs (light, medium, heavy). While you're there get a fresh cap & rotor if yours aren't so good. Then go home and R&R Vac Can and R&R the two springs just under the rotor ... replace with the "middle" tension springs. Mist the inside of the dist down with a shot of WD40, making sure the springs & weights articulate freely. Button it all back up and reset you timing with a timing light. This choice of parts & this method will get you firmly into the ballpark. You can experiment with different spring set ... even 1 light & 1 mid. BTW ... the vac can & spring kit at NAPA will set you back a total of about $20.
JACK:gap

 

[drags1998]

I voted engine componants, If the engine is in good shape,and your budget allows,I would start with a CAM & LIFTER change.Call the cam co. yourself, Be honest with them,(they will have LOTS of questions) and they will help you choose the correct set-up for your car!!! Ihave always had good luck withComp.Cams or Crane Cams.While your in there,change the TIMING CHAIN & GEARS, and inspect push rods & rocker arms. After this, maybe HEADDERS and intake work!!! Good Luck!!!!!

 

[Wolverine]

Jack,

Thanks for the advice. This is just what I needed. http://www.corvetteactioncenter.com/forums/newreply.php?do=newreply&noquote=1&p=357888#

By the way, I contacted Lars about his recurve kits. He no longer sells them because he is so busy with other projects. He is a real guru on corvette tuning, though.

 

[AKRAY4PLAY]

what kind of power are you looking for??? what is your budget?? answer those two questions and things will come closer to reality. if you want big power, nuke and re-pave. you will have to re-work the exhaust, motor internals, new heads, ignition and induction. cooling is probably the only thing that does'nt need to be re-worked, but it is still a good idea.

if you are looking to improve on stock for next to nothing, get some headers and an HEI ignition. next step would be heads. Brian

 

[74bigblock]

need I say more? ....

 

[rpounds]

Personally, I believe you will get the most bang for your buck with a cam change. The problem that many people run into is trying to run too much cam for the rest of their combination. Crucial to cam selection is compression ratio, third member ratio, stall characteristics (if running an auto trans), the ability of the heads to flow, etc. A cam also can be selected which will provide torque in the lower RPM ranges or HP in the higher range. When looking at a torque/hp curve, the two will cross over each other at some RPM. But where they cross over can be controlled by cam selection.

With that said, if I could only make ONE change and one only, I would look at heads. The heads are where you make the real power and torque. As with cam selection, head selection can be a bit tricky too. For instance, if the intake ports are too large for your combination, torque will suffer. On the other hand, if they are too small, HP will suffer. So you have to choose carefully.

I'm going to put a PS in here regarding headers. I mentioned above that head intake ports need to be sized correctly for the specific application. The same is true for headers. In most instances, large tube headers are not a good match for small blocks. Small tube headers will serve better, especially where torque is concerned.

I guess I edited to add that statement because it can't be stressed enough that components have to be matched in order to come up with a combination that really works well and makes a good combo of power and torque. Here in Southern California, it seems that the neighborhood speed shop is nearly a thing of the past. However, if you can locate a good one, they can point you toward a combo that is proven.

Hope that helps a little.

Ron

 

[WhalePirot]

Gee, Ron UR in the heart of what is left in SoCal for speed shops. OC Speed is a great one!

A total 'system' approach is the only way to maximize the return and surely, header size is determined by engine design. I understood the poll to be about bang for buck. Headers/exhaust is almost always the place to start, but will require minor tuning.

Mods to the body for blowers and opening up the engine are not cheap, while headers are minimally invasive and will be added at some point.

Other threads showed the choice of air filter to have very little effect, even compared to NO filter.

Synthetic, thinner oils may reduce friction due to the thinness, but may not lubricate as well, while offering better high temperature performance. Little power payoff there.

 

[rpounds]

Yeah, we have the luxury of having some decent speed shops around here in SoCal, don't we? There is one that is almost within walking distance of me here in Whittier. There's even a 'Super Kragen' in the next town that carries a lot of nice goodies, mostly Edelbrock (although that is not the brand of my choice in most instances - not knocking them because they have great stuff, just not my preference). I don't know how the rest of the country is fitted out with speed shops, but SoCal used to be the #1 place for that type of thing. There certainly aren't as many as there used to be which is too bad. I suppose that the strict smog laws had an early impact on a lot of them. Fortunately, there is a wealth of parts coming from the manufacturers now-a-days that are C.A.R.B. certified for use in California. That's good news for any gear head that lives in a smog restricted area.

Ron

 

[norvalwilhelm]

I have run the gaunlet of performance mods and nothing compares with a blower. Even my 10 second nitrous motor never pulled like my 8-71 blown 460. For smooth driving, shear torque nothing, not a supercharger, not a turbo matches the blower

 

[lov-n-life]

there is no substitute for cubic inches stroke it

There is no replacement for displacement! 100% agree!

Well ok, I'll conceed that bolting on blower is pretty close to stroking a 350 up to a 383... but who wants to cut holes in the pretty hood to make it fit?!:L

 

[74bigblock]

What is the difference between a blower and a supercharger???? Aren't they the same thing?

 

[JohnZ]

Yup, just semantics - both are driven mechanically from the engine, vs. turbos, which are driven by exhaust gases.

 

[dman]

bang for $ nos ..hands down....100 shot stock motor no probs.. high millage. not a prob ..

 

[Evolution1980]

100 shot stock motor no probs.. high mileage. not a prob ..

I don't know that I'd say it that casually...but then again, that's not my expertise.

 

[dman]

useing it on a high millage 70 camaro bone stock 150k on it 2years now no probs.. one time eng got dry shot melted 3 spark plug tips ..changed plugs .2years still going strong ...no bs .....

 

[Stallion]

How true.
My stock '82 ran 15.704 @ 86 MPH w/ OEM 2.87 gears (86 MPH @ 3500 lbs calculates to 151 RWHP);
with 3.73 gears, it ran 15.003 @ 91 MPH (179 RWHP), but I think the car 'nosed-over' before the lights (poor fuel pressure?).
If you can live with poorer MPG, and increased RPM, where else can you find 7-tenths, 5 MPH, and almost 30 HP for the money (I had $550 invested, total), short of N2O ?

Well a gear ratio change wouldn't affect horsepower, would it?? :confused

 

[bossvette]

Well a gear ratio change wouldn't affect horsepower, would it?? :confused

the gear change gives the horsepower you have a greater mechanical advantage then it had before. Kinda like moving away from the pivot point on a fulcrum it takes less force, but greater movement(rpms) to get the same result.

 

[Stallion]

I don't understand. :confused