Waking up my 350 SBC

[milled]

Originally Posted by ChevyDude

the lift is 488-510 w/ hydralic lifters...that's nothing...not even a roller.

That's the limit, it'll run but run it leaner.

[LONGHAIR]

Far be it from me to "tell" anyone how they have to do anything.
My point was exactly as covered by several others, there is a big fuel mileage hit with a double pumper, for no real performance gain to go with it.
It's not like there is some huge horsepower advantage. You could measure it on a dyno...and maybe see it in quarter mile times, probably as dependant upon traction as much as anything.
Properly tuned, I doubt that anyone could tell from the driver's seat, so why take the mileage hit? or the price of the carb itself?

As a side note:
ChevyDude, go easy....the point was already made.
You could have explained a little further, but certainly didn't have to....no one should have commented in that way.
You really should not have retaliated though....I realize that is far easier to say than to do though.

III. No pissing matches. Its fine to disagree, but once a thread has run its course, and degenerated into little more than an insult fest, it will be locked. While this will require a judgment call by the Administrators & Moderators. The members of this site can keep our moderating to a minimum by exercising a little discretion and self- control.

[67_C-30]

Originally Posted by LONGHAIR

Far be it from me to "tell" anyone how they have to do anything.
My point was exactly as covered by several others, there is a big fuel mileage hit with a double pumper, for no real performance gain to go with it.
It's not like there is some huge horsepower advantage. You could measure it on a dyno...and maybe see it in quarter mile times, probably as dependant upon traction as much as anything.
Properly tuned, I doubt that anyone could tell from the driver's seat, so why take the mileage hit? or the price of the carb itself?
.

Again, I respectfully disagree. I have compared them at the track and on the street, and there is a very significant difference. I have seen more than 2 tenths difference in the 1/4 and I have seen 30-40 ft lb difference across the torque on dyno tests comparing the same cfm carbs on the same engine. In fact, a 650 DP will wipe the floor with a 750 VC everytime at the track. I have proved that time and time again. A vacuum seconday carb will keep the secondaries from opening fully until fairly/very high RPMs. That hinders the torque curve throughout, as well as hurt peak HP. Vac sec carbs are only better in heavy street driven cars with no stall and high gears turning very modest RPMs putting around town with the occasion burst through the gears.

As far as mileage, its not that much (if any) difference. A double pumper has progressive linkage, and the secondarys are not squirting fuel just driving around. That's a common mistake people make. Some people think that all 4butterflies pen as soon as the throttle is opened, but isn't the case.

The bottom line is a vac sec carb is a compromise, and it comes at cost. They are fine for a stock or nearly engine, but there is absolutely no advantage to having a vac carb on a heathly engine with an aggreesive cam, aluminum heads, low gears a stall. With a difference of 20 peak HP and 30-40 ft lb of TQ on the dyno and 2-3 tenths at the track, I'd go as far to say that I doubt that anyone could not tell the difference from the driver's seat. I have been building race engines for nearly 15 years, and raced street/strip and bracket cars for 10, and this has been my experience.

[special-K]

Sounds like it`ll be another honkin`little 350 to me.I never knew it had to be as complicated as some make it appear.There are proper combinations.But,in the end they`ll all run and most of the time we don`t see the difference.

[ChevyDude]

Engine was removed from truck today and heads were removed, I discovered the block had low compression dished pistons. -18cc dished pistons = Low Compression. Decisions Decisions. So I decided to buy a Smith Racing 3970010 SBC w/ SRP flat top pistons w/ forged crank he had just finished building. We installed the Crane 488/510 lift cam and Sealed Power hydralic lifters and the Cloyes 1100-SP double roller timing chain. Installed Cam @ 4 degree advance at the crank. Build specs have already been on the Dyno and produce 418hp at 5700rpm. By advancing the cam timing 4 degrees, it achieved hp numbers of 418hp, yet maintained torque number near 400 ft lbs all thru out the power band. Now to bolt on the top end.

[special-K]

I think you guys are saying the same thing.Just,one is puttimg emphasis on track/dyno and the other on street use.One`s a comprimise on the track and the other`s a comprimise on the street.They both do the job with minor differences when it comes down to it.The main thing is to have a carb suited for your engine build/use.

[Bob 68327]

I say it's your truck and your engine build it however you want !! I run a DP on mine my cam is a 292/.510 I have an auto trans w/a 3500 stall and I drive it on the street . Build that screamer and Drive the wheels off it !!

[ChevyDude]

I can tell you one thing for sure...I am building this engine the way I want, and it will be a runner for sure. Remember I said Hod Rod...never gonna be an everyday driver, but it sure will get up and go when I mash the pedal. Here she is...don't ya think she deserves some ponies???


Lots of opinions here when it comes to an engine...I can see that clearly. I guess some of you will think I am misguided or nuts on my other project...this is what I built for my 68'. It's a 496 with a 1050 Holley Dominator DP flowed & bowl blended by Chuck Nuytten..and it's got a solid roller cam and lifters, oh the lift is .650 and the Edelbrock heads are rectangular port, K-Motion dual springs, roller rockers, 10.5-1 compression. Gas mileage estimated at around 7mph, LOL. But HP...some where between 700-750 LOL.

[sierragrande71]

Sweet-looking truck and engine!! That's all I have to comment.

[ChevyDude]

Originally Posted by sierragrande71

Sweet-looking truck and engine!! That's all I have to comment.

Thanks! I'm doing what I know works and is fun to drive. If I want to go get groceries or pick up the folks at the airport I'll take my crew cab 05' Chevy Colorado truck....it's got a 5 cylinder and you can barely hear it run.

[special-K]

Originally Posted by ChevyDude

Thanks! I'm doing what I know works and is fun to drive. If I want to go get groceries or pick up the folks at the airport I'll take my crew cab 05' Chevy Colorado truck....it's got a 5 cylinder and you can barely hear it run.

I say put the 5 cyl in with a supercharger,nitros,and...

[ChevLoRay]

I'm impressed. It's painted "Arrest Me Red", so a little ooomph under the hood certainly ain't gonna be out of place.

You evidently know what you want and how to get it done.

What works for you is what works for YOU. I say, "Go for it".

[Bob 68327]

Don't forget the high performance Left hand blinker fluid !! Good for 20 Horsepower !!

[steelhorse]

I think it needs a turbo or a supercharger or both,with nitrous.

[ChevyDude]

Originally Posted by steelhorse

I think it needs a turbo or a supercharger or both,with nitrous.

That's great...thanks for thinking!

[Stocker]

With respect to the late Roy Scheider..... you're gonna need bigger tires.

[ChevyDude]

Originally Posted by Stocker

With respect to the late Roy Scheider..... you're gonna need bigger tires.

Foul! Off topic...opinion rejected, next.... LOL!

[ChevyDude]

I am glad this thread has taken a comic turn rather than the other route. Thanks special-K for the 5 cylinder vote! and ...yes Bob picked up that performance blinker fluid yesterday!

[steelhorse]

Screw it,just send me all the performance parts and buy a crate motor

[ChevyDude]

Originally Posted by steelhorse

Screw it,just send me all the performance parts and buy a crate motor

Steelhorse ...you better go back and read thru this thread again...My plan is poorly thought out and the performance parts I have bought will do nothing but eat gas, and think of the money you will save when you buy YOUR crate motor, LOL!!!

[steelhorse]

I am a mechanic,I dont think we are allowed to buy crate motors.(It just seems wrong)

[Frizzle Fry]

With that 496 in overkill you should go to the other extreme and build a 230 for lil red

[ChevyDude]

Originally Posted by Frizzle Fry

With that 496 in overkill you should go to the other extreme and build a 230 for lil red

I think it had 190 hp as it was...absolutely embarrassing to drive. Heads were low compression casting number 333882, which I believe were 1.90 1.54 76cc smog heads. Combine those heads with the dished pistons = Dog!

[big_al_71]

I am in the process of deciding wether I should go with a big block or just a 383 stroker. But after seeing the pict of that motor I think I just made up my mind .....lol

[70rs/ss]

I am going to edit, well add on to my response above. I read your OP and then read cdowns, then reread your OP and saw the heads were going to be swapped, I was right there with cdowns till I saw the part about the heads. So, I hit respond and didn't read to the end (I know read it all otherwise you add stuff that is already there) so my thoughts were dead on, just late to the party.

I am adding this to be sure to say, I love both of those trucks and I am with you, but as you found out my advice on not messing with an unknown came to you anyways. A lot of us buy vehicles with an unknown SBC under the hood and some of us start adding, bigger cams, intakes, headers, carb, etc and still have a dog or worse yet build a hot rod that breaks the bottom end. I just try to see that the extra $$$ for a short block makes the $$$ spent on the top end a good investment that'll last.

OBTW I don't condone cdowns method of stating his point, even though i am pretty sure it was a matter of not seeing that the heads were going to be swapped. Diplomatic isn't an adverb I'd use to discribe his manner, but neither is mine all the time.

BTW did ya ever decide on the 5-speed??? TKO600!!?? I am so getting there!! I am about ready to axe all of my "projects" and focus on my 70RS/SS Camaro with the Vortec 383 I built with a TKO600, and maybe a 72 2wd Blazer with 500ci BBC and a TKO600. When my back is all better from the surgery (should be 8 months or so to be 100%) then i am into the Camaro for sure and probably the Blazer as well!!

Can't wait to see picts of Lil Red with it's new fire breather!