Technical Looking for a n experienced tuner in my area

Hey Guys,

I'm a long time follower but this is my first post on this forum, and I have a question:

I just finished my first frame off restoration on my 65 chevelle 300. The car is primarily a street car, but I plan on taking it the strip some. I have a pretty strong 327 that I can't seem to get all the potential out of. I keep making changes to the car, but it's hard to know if I'm maximizing the car's potential, seeing as this is the first performance motor I've built. I know I have it CLOSE, and I think A LOT of my issues is in my Holley 650 DP.

My question is: Does anyone here know of an experienced tuner in the Greenville SC area they can put me in touch with? I'm pretty tired of messing around with it/shooting in the dark, so I really need someone the help me out.

This is the most relevant area I could find to post this, so if someone has a better suggestion of where this might get more responses please let me know

Any info is really appreciated !

 

you do know what a tuner is right ?

 

I just typed in "tuning Holley 650 double pumper" in google and got a shit load of hits including 3 you tube videos. So you don't need to be shooting in the dark. Do some research on the web and follow some of the information out there and you should be able to handle tuning the carb ok if you built an engine.

Also, don't change too many things all at once. Do one thing and make sure that is working properly before attempting to change something else. Doing too many things all at once can get you chasing your tail trying to figure out which or what change either helped or hindered what you are attempting to do.

 

Curious..You said it's restoration, but 65 327 Chevelles came with a 4 GC, an AFB, or quite rarely ,a Holley 585 vac. secondary carb .
So, it's a resto then, except for the engine?
The DP carb could be a big problem. How much converter, or is it a 4 speed?

 

hey Mark, I didn't plan on restoring the car back to original. . the car was an incomplete mess when I got it.

My plan was to sort of make a tribute to a stripped down 300 with dog dish cap, not many amenities/options, etc. I can send you guys pictures if you like. . I have 2700 worth of stall. 3 speed auto. . . I get that a vacuum secondary would have been a lot better for street driving, but my crew at my local machine shop encouraged the double pumper since I really want this thing to perform rather than be street friendly.

I know my combo is workable.. Is it perfect? No, but it's what I'm working with. Sure I'd rather have a 4 speed, but I didn't have the money to do a convert as the car has always been set up for an automatic. So that is what it is. Like I said, I have the setup CLOSE but just can't get it quite right. Everyone around here wants to suggest shit I should do but honestly the more I learn the more I realize how hard finding an old school hot rod mechanic is.

Thanks for the looking that up Gordon. And yea, I get that there's lots of info out there, but I'd really like to learn from someone and not videos. I appreciate it though. That's what I've been doing; changing a little at a time. Honestly right now I have very limited time to work on this. Again, I'm super close to having it right but it's just frustrating the hell out of me.


I have the car where it will spin the tires hard if I hit the gas hard rolling anywhere from 0-15 mph. I have a 4.10 rear end gear with positive traction if that helps. It accelerates pretty violently I just know there is more to be gained, and since I'm not really experienced at this stuff it's hard for me to even explain what it's doing. Hence, why I'd like to find someone to give me a hand. Hopefully that makes sense.

And yes, I know what a tuner is thank u.

 

Maybe this will make sense: It's almost like I need someone to ride in this car with me so I can show them what I mean when I say it isn't performing to full potential. I hope that makes sense. I know there have to be guys out there that do this stuff!

A side note: I found what was supposed to be the best dyno shop in town back 3 months ago. I made an appointment with these guys who, unknown to me until after the fact, only had solid experience with "tuners" (hondas, acuras, etc). They thought cam valve timing was the same as ignition timing and proceeded to set my timing with the cam card (which was already set btw). They had no idea what mechanical advance is, carb pump cams, etc. These dipshits screwed my car up so bad that I had to have it towed from their shop. EVERYONE said these guys were the best.

Hence my frustration finding someone around here .

Thanks guys

 

That's what restore or restoration means though - the process of returning some thing to its original state.

Sounds like they buggered it up pretty good, what'd they charge for the privilege? Get in the manuals and study them, and you'll understand it, even if you have to hire some of it out. Start with the basics and determine that everything is straight. Compression and cam phasing, ignition timing and/or distributor curving, carb tuning etc.

 

Is your Holley 650 DP a spread bore or a square bore? If it is a spread bore they are hard to tune. If you want to get it going properly it needs a 600 or 650 DP square bore. Part no R4776 or R4777. Holley still make these but they are not emission legal. they are very good to tune and in my experience run well out of the box. Be wary of a lot of the later Holley carbs as they are designed to meet some of the current emission laws and are difficult to tune.

 

I'll throw in some thoughts too. 1st and most important word to embrace, COMBINATION.

To cite, suppose one had a .625 lift roller cam and an 830 annular discharge Holley but a 1400 stall convertor and 3.08 gears. Going nowhere, right? Well that is unless you had about 2 miles and even a push vehicle to get it rolling.

Cam lift and duration can make or break your performance. The reason why we sometimes hear about 15:1 compression ratios (static) is because of the huge amount of overlap in some cam specs. It's needed to build "proper" cylinder pressure at the point where both valves close as quickly as possible.

That said, knowing what cam specs, compression, valve size and weight of the vehicle are a big help. Our world is fullof old wives tales like grooved crank journals and pin-pricked combustion chambers, small headers to get "back pressure and more compression", and several other foibles that essentially will have your car trying to win a hot dog eating contest with a belly full of pancakes and bad case of constipation (!).

At 2700 that's a loose enough convertor without being too loose for street/strip fun. A time slip is the best dyno in the world. You can tell exactly what each change nets with a test pass, but you need to be nearly "religious" about conditions and consistant test procedure. If you leave at say, 2000 RPM, get a 13.02 time slip, make a change of 3 degrees advance in the timing you MUST leave at 2000 RPM again, preferably within less than an hour of the last pass. Make a run at 1:00 and the next at 7:00 pm, was it the drop in air and track temp or the timing that got you the 12.90? See what I mean?

I try to get questions answered by the ones asking by throwing in some ideas and standards, basics that never let you down. You know what it's doing whether it's laying down at 5000 RPM, backfires on launch, falls flat on launch and picks up as RPM rises and every condition in between. Maybe it runs awesome and is just slow to put a grin on your face because it's just "not there" or at least not what you expected or were told to expect. Give us some detail on both, what it's doing, what you thought it should do, etc.

 

Ok fellas, here we go with my engine specs:

comp cam 12-224-4 (282 duration intake and exhaust, 236 duration @ .050 lift, valve lift .495, lobe lift .331) stainless 2.02 valves, dome dome 12:1 pistons, performer rpm air gap intake, full length ceramic hooker headers into flowmaster original 40's and H pipe dumped at the mufflers, electric fan, aluminum water pump, mallory 6a ignition box, ready to run mallory dist with largest (black) bushing available installed (running 35 degrees of total timing and 18 degree advance curve w/ the 2 lightest silver springs/fastest curve they offer..this curve seems to help a lot), msd blaster 2 coil, fuel mixture of 112 and 93 octane fuel giving me around 98 octane typically, small journal crank, ported double hump heads, 1.5 roller rockers lashed at .019 cold as instructed by comp cam rep, pushing about 6 psi of fuel pressure consistently through a holley mech pump, 3050 lb car..I think thats it..? If I missed something tell me.

This converter gets me to around 3000 rpm quick in any gear which I believe it exactly what it's supposed to do since that's where the cam comes in.

Highlander, does that help?

Oh, SQUARE BORE holley 650 DP, Midroad.

Here's an example of what I've got going on: My buddy and I just went for a spin around town. The last time he rode in the car I had 70 (front) and 76 (rear) jets installed. Since then I changed jets to 67 and 70, made a slight fuel air mixture adjustment, and raised my rear float slightly. I noticed a MONSTER diff in acceleration; especially from about 3000-5000 rpm in all 3 gears. Where before, i made these adjustments the car felt flat through that range.

After the ride today, he said "this car feels like a diff car," which it does. I'm thinking about trying a larger squirter (I have size 28 front and rear now.) Maybe I'll go with a 31? Or change pump cams? I dunno. This is where I get confused. Do I have much more to gain? Prob not..But there's a little more I know it.

A lot of people said maybe I'm was expecting more, and I was starting to believe them until I made these changes. believe me, they are noticeable. Before these changes the car felt like an absolute DOG in 3rd gear (3000-6500 rpm). Now it feels like a rocket.

I don't know how to describe this but there is still a spot in the rpm range..maybe between 5000-6000 or so where I think I could be building more power but for some reason I'm not. My cam is designed to build from 3000-6000 but I really think my issues are with my Holley since those changes I described made such a diff. Those small changes I made got rid of the flat spot from 3000-5000. Literally a jet change, small rear float adjustment, and 1/4 turn on my fuel air mixture! It was night and day! No lie.

If I could get one of you guys to ride in this car I could show you!! Haha. Tell me whatcha think!

 

Oh, 4.10 10 bolt rear end with pos trac Detroit locker, 255 50 15 rear tires and 225 70 15 front tires. The only acc I run is an old style saginaw ps box

 

Elliot, There's some good advice here.
Seat of the pants doesn't always tell the tale.
Your drag strip 60' times will tell you how hard and consistently you are hooking, but also tells you how hard and clean your carb is allowing you to leave the line. A .02 improvement there usually doubles in 1/4 mile ET. MPH tells you how much hp you are making.
That being said, I doubt you'll ever 60' or ET with that 650 DP as well as you would with a good 750 Q-Jet or even a 735 3380 Holley, after tuning them at the strip.
Not sure what your machine shop was thinking. Maybe no real world on track experience.

 

I don't know man, thats just what they told me. The drag race every weekend, but who knows. Maybe I can try one of those suggested holleys once I can afford it. I cant find a 3380 735..?

In the meantime what could I do? I have a full pump cam and jet assortment. I currently am using the pink cam. I have an off idle hesitation that is noticable. Larger pump nozzle/s?

 

Do they WIN every weekend?

 

Sorry, I meant a 3385, like on BBC solid lifter engines.I know nothing about Holley carbs.
I take that back. I know enough to not to want to know anything about them.
I'm surprised you haven't got more responses. Everybody and their brother is an expert on Holleys .What I always hear anyway.
I'll bet you machinists that use DP's, don't have anything close to your street and strip combination..Just sayin'..

 

Try an orange pump cam in the #1 position. If that doesn't work try the .031 squirter. But I don't think your problem is the squirter or pump cam. 5000 rpm's is way past help with the squirter. I'm wondering why you dropped from a 6 jet spread to a 3 jet spread on the 2ndary. Try 73 or 74's on the rear.
But I agree with Mark Yak, that 650 ain't big enough for that motor and the rpm's you are wanting to run. Check into Quick Fuel Technology carbs. They are great carbs.

 

Ok ill try the orange cam, and maybe it will help the hesitation issue. Then maybe a 31 squirt nozzle. I have 67's up front and 73's in the rear. Sorry, I have to correct myself. my jet combo is actually 67 up front and 73 in the rear. Does that sound good?

thank u very much

 

There should be lots of sharp carb /tuner guys in your area with all the round track racers and drag racers in your neck of the woods. I am surprised you can't find anybody.
A well built 750 vacuum secondaries carb would work great on your car. I would like to see what a professionally built Qjet would do for your combo. Not as sexy as a Holley ,but probably faster.

 

heh...I just read through this thread, and was thinking 750 vac secondary, also. Sure made my 396 run good, way back when, the rest of my setup was pretty similar.

 

Anyways, on a more serious note...the jets that were in your carb were a bit too large, you put the primary back to stock, and the secondary a bit lean (it probably came originally with 67 and 73 jets). I'm not surprised you noticed a big improvement. One neat thing about aftermarket performance carbs, is that if you have a carb that is close to the right one for the application, then nine times out of ten it will work great with the jets that came it it from the factory. The first thing to do when "tuning" a carb is to get it back to stock configuration!

and I also think that you are probably pretty darn close to having it working as well as it can. Time to build a 427

 

Might read up on power valves too.

 

Squirrel what do you think about my 650 dp? should i just keep it? What about trying new pump nozzles. I have 28s on now. what would u try? 31?

My next motor build will a 383 or 400. not sure yet

 

Does it have a flat spot, or sometimes sneeze, when you open the throttle? or is it running good?

the 650 dp should work ok on that combination. It might not be the optimum carb, but you should be able to make it work.

 

really the only thing i can describe is an off idle hesitation right when u hit the gas from a stand still

 

what should i try for that?

 

try the pump squirter first, see what that does.

 

what size do u suggest? i have 28 now

 

try 31, see what happens

 

Are we talking a hesitation driving away from a light, or when whacking it to the floor from an idle?

 

k ill give it a try and let u know how it goes