[79monte]

What is the rev limit of a 350 chev borded 60 thoushndths over, crank turned .010 under, reconned rods. 9:5:1 compression, gasket matched ports, 600 vaccum secondary holley carb. 2 bolt main. new stock oil pump, HEI ignition, 1 5/8 primary headers and 3 in collectors, Performer intake and 8 mm wires. Also what could up the red line?

 

[lakeroadster]

Balanced?
Roller Cam?
Solid or Hydraulic Lifters?

 

[jimm]

no more info. than given i would say 5500.[on the safe side]wanta go up?balance!roller rockers,hydraulic roller cam[matching components].actually ,lakeroadster answered before me[ with his questions]which were as good as answers!theres tons more stuff that can be done.how big [deep]are your pockets?jimm

 

[BadBowTie]

One thing to remember is the Preformer Intake you mentioned is suggested to run from Idle to 5500rpm's. If you go higher than that, It might not breath well, and rob power.

 

[79monte]

Hydralic cam and lifters,what does it cost to balance a set up, (pockets are shallow).Also does the two bolt main hamper rpm potential?
79monte <img src="confused.gif" border="0">

 

[BadBowTie]

I'd say that with your cam being non-roller, and the hydraulic lifters, I wouldn't rev it past 5500 and even 5000-5200 to be a bit safer. I would think that the 2bolt block would limmit the rpm's if was more of a really high preformance engine that was constantly run past 6500, and made over 400hp. with your setup 5500 and a 2bolt should be fine. My guess is that something else would give up before the main caps.

From what I've learned The valvetran is the most limmiting factor on Rpm. But once you start getting up there you need stronger rods, and even a stronger crank. along with roller everything- cam, lifters, full roller rockers, screw in rocker studs. which means very deep pockets!

Just wondering why you'd want to run it much higher than 5500? is it a manual or auto trans?
Because I just put a 350 into my 69 caprice with a auto trans. I never usualy rev it past 4500 and almost never up to 5000. I would put money into getting more low end torque out of it.

 

[Jooooooe]

Don't worry with it, when it quites pullin', shift. Some things aren't meant to be so technical. But if you must, the grind of the camshaft will determine (for the most part) your engines operating and output range. Most stock american made V8's redline at or near 4800 RPM. You can tell the difference between a stock cam and performance cam by sensation (the non-dyno approach). A stock motor usually comes on from idle and pulls gradually to the end of it's power curve(actually on a stock motor it's not much of a curve at all) and then sharply drops off. The more radical the cam profile the more dramatic the sensation, provided the rest of the motor is matched. A mild profile cam in a stock motor will produce an increase in horsepower and change the power curve, the power from idle may actually decrease, but at a certain rpm (whatever rpm the cam is rated to start working at) you'll feel a sudden climb in horsepower that should build up til the end of the curve and slowly start rounding off.

 

[79monte]

Great suggestions guys, that gives me a really good idea. Just to clarify, I didn't really plan on surpassing 5500, I just need to know where to set my red line, basicly so i dont try and run it up to 6500 thinking that my hard earned money will hold my "little 350 that could" together. Also, TH 350 behind it.
thanks again,
oh, any cheap suggestions on building power/ torque.
Thanks
79monte

[ March 07, 2002: Message edited by: 79monte ]</p>

 

[jimm]

hello monte!try finding acarb. spacer from 3/4 ton pickup.went between carb. and air cleaner,about 2 to 2.5 inches tall.will give siome low end torque increase.[bout as cheap as it gets]see ya, jimm.

 

[jimm]

hello monte!try finding acarb. spacer from 3/4 ton pickup.went between carb. and air cleaner,about 2 to 2.5 inches tall.will give siome low end torque increase.[bout as cheap as it gets]see ya, jimm.

 

[79monte]

How about one of those custom filters that stick out of you hood and have the (butterfly valves?)
I'm not sure what they're called, but i hope you know what i am talking about. Do those do much for power. It will have to stick out of the hood because of minimal clearence, I can only run a 2 in filter as it is now. Thanks
79monte

 

[Phat]

Everybody is correct with the balance deal. Having run 2 bolt main blocks all the time on NASCAR short tracks.We used sportsman rods ,good valve springs, NO roller cams allowed,cast iron unported heads(or you would get spanked by NASCAR),steel crank and ran them night after nite from 4500-6800 with no failures. Balancing and clearances are real important.If its a stock motor keep it were ever body says 5500 @ the most.
Cams and gears are important,you dont allways have to twist the crap out of them to make power.

 

[jimm]

the air breather cover you described [commonly used on blower motors]isnt the ticket for breathing increases.a k&n air filter will help.jimm

 

[Rex Tribble]

Not knowing your valve train, I would caution over reving it and floating a valve. If all were built right with good materials but on the mild side, you should be ok up to 5500 rpm. If you have old valve springs on your heads you run the risk of dropping a valve if you go much over 5000.
As far as performance goes your car will pretty much tell you when to shift. When it quits pulling, shift.

 

[BadBowTie]

The Carb spacer would help out if you could spare the hight, but it sounds like you can't unless you cut the hood open and put a working or fake scoop to add more room.

Also there are 2 main types of spacers: 1 Open- for more top end, because it increases the plenum volume. 2 ones that have 4 holes- for more low end power, because it increases the velocity of the air fuel mix.

I wouln't put one of the butterfly air cleaner jobs on unless you are going for looks- the only thing it would do it get colder air for your car. You probably would not notice any difrence.

One other option is a cheeper Nitrous system. one that goes from 50-100 or 150hp you can find one through summit for $350 from edelbrock or $370 by NOS.

I have a setup almost exactly like your 350chev 4bolt, preformer intake, Mild Cam, headers, dual 2.5" exhaust, HEI, with a Th350 behind, and 12bolt rear.

In my opinion more lower end power to really get you moving fast from the start, with out having to run the 4.11 gears is the best way to go.

If it was my choice,
I'd get a bit higher stall speed torque converter(just allows engine to rev higher before it takes off [on mine the power dosen't hit till about 2000-2200rpm $80-100)-
A K&N filter(if you don't have one)(10-15hp for about $50)
A small Nitrous system(50-150hp for $350-400)don't go too crasy on a 2bolt and if it just has cast pistons.
I've also heard that roller rockers could help some, but I'm not sure how much(10-20hp?? for $150)
Also your 600 could be limiting the hp just slightly a 650-700cfm would be better sooted in my opinion
Hope my research for my engine can help you out some.

 

[79monte]

Thanks for your suggestions guys, they are great,
If I used nos, what kind of damage would it cause to the engine, If any? I like the idea of it, but the engine needs to last as long as possible.
Thanks for any more possible suggestions too.
Thanks.
79monte

 

[79monte]

Would a holley 750 double pumper be too much carb for this engine? .450-.460 cam, 60 over etc. The intake is a edlbrock performer spread bore . The carb would also be a spread bore.
Thanks,
79monte

[ March 13, 2002: Message edited by: 79monte ]</p>

 

[jimm]

hey monte!for the best volumetric efficiency for your setup a 650 or 670 carb. will be best.ok, let me try again,you will actually lose some low end torque if you go to a 750 carb.also you wont gain very much on the top end[remember that 5500 redline?]please understand that this is how its been taught to me,maybe some of theguys that have alot more experience and knowhow will weigh in on this subject.see ya!jimm

 

[79monte]

Sounds good, do you know of a way to make a 600 flow more to get that efficiency? Do the holley trick kits do anything for CFM. Am I going to have to buy a new carb to realize the potential this engine may have. I know I ask a lot but the guy helpong me now is getting fed up and tired of my questions,I really appriciate all our your help.
Thanks for the tips and on going suggestions.
Also, does anyone know If porting is worth the effort, I've heard it is, but no one has commentes as of yet.
Thanks again,
79monte

 

[BadBowTie]

What's this sight here for.... To ask Questions, and get answers

If you want to get the most life out of the engine I would stay away from Nitrous Oxide.... to put it simply It makes more power by putting more oxygen and Fuel into the engine to burn. Thus you get higher cylinder pressures and more power, but at the cost of extra stress on you engine.

To get more life keep the reves low! reving it high just puts more stress on all the internal parts, The forces the engine incounters at very high rpm's is tremendous, and will shorten the life of the engine!

Yes Porting the cylinder heads will increas power
on a 350 chev I've herd a 20hp increas is common on a good port job... 1hp per 1.5cfm increas is reasonable. this link provides some good info
<a href="http://www.sa-motorsports.com/diyport.htm" target="_blank">http://www.sa-motorsports.com/diyport.htm</a>

From what I know I'd say Jimm is right on as far as the carb specs. I just run a crappy old Q-jet on mine (My carb is a poor reman. carb that's why it's crappy), But the engine runs very strong.
My engine is setup almost Identical to the one you mentioned, and mine is plenty powerfull for my 2.5ton monster. It spins the tires with ease around a right hand turn with a stock th350 auto tranny. ( infact I almost got into a situation today because I gunned it at a yellow light while stoped for a left hand turn and found myself fishtaling because of the tire spin Luckly around here I'm used to driving in slipery conditions)

I would also agree with jim that the holley 750 is not the best choice. IF it were my choice I'd stick with the spread bore carb( guessing you have one since you have the intake for it) otherwise, you might consider a Road Demon carb- 625cfm- and looks like a styled up holley. summit sells it for $300 I think, I'm not sure if there would be a problem with your intake and a square bore- they do make adapter plats, but it might bolt up any way.
sorry it's a long post again, but I've just done alot of research for my own engine and since your's is almost identical, I think it might be helpful.