I was talking to a guy at work today "fNord guy" and he told me every 350 he's ever driven has been slow. I know that most of them are unless modded even some modded ones are out of tune. But do you find this to be true in most cases?
My friend just bought a sweet 68 chevell malibu with a 350 big cam performer rpm manifold holley carb headders all that good stuff and the thing doesent run worth crap. It should!!
This is the same guy that spent 6k on a 355 in his sweet 72 nova and that doesent run either mid 15's @ 82mph.
My lg4 has more power than bolth of these cars.
Whats the deal? Why are these so slow? What are these engine builders doing wrong?
From where I stand building an engine is straight forward, these people who get paid to do this should know how to build one better than me right?
For the life of me I cant understand whats going on with these 350's Ive driven lately a well tunned 6 could blow thier doors off.
Venting and pondering why.
SSC

 

Like many other back-yard engine builders I've known in the past, 99 times out of 100 they selected a camshaft that was too damn big, and would have been more suitable in a 400-427 small block. And if you think 350s are weak, I have a word for you...LS1 .

------------------
1990 IROC 350
Mods: Too busy trying to make it run right to mod it.
Airfoil, Dynomax cat-back, MSD coil, 180 t-stat, Bald Eagle tires,
Hypertech fan switch, Accel 23# injectors, Holley AFPR, ported plenum,
Ported Daytona Yellow stock base, Moroso valve covers, other stuff,
Ruger P95DC, hot wife, new oil filter, thick rubber floormats, no cats.
18.0 @ 85MPH since I'm one big-a$$ MF
"It's better to have and not need than to need and not have."

 

plus you also have to think about the fact that those 350s were in heavy cars. though these engines probably just weren't tuned correctly(or wrong components chosen)

------------------
'86 IROC 5-speed
305 LG4
edelbrock performer rpm intake
edelbrock 600 cfm carb
msd pro billet hei distributer
'95 3.23 rearend
hotchkis rear suspension
PST front polygraphite suspension

 

And if you think 350s are weak, I have a word for you...LS1

It's a 346




------------------
91 Z28
Best Time Slip:
60' - 2.098
1/8 - 9.137 , MPH - 76.21
1/4 - 14.213, MPH - 97.55
Performace Mods: B&B Exhaust, few free mods.
Appearance Mods: SS wheels, 2.5" Cowl Hood... New 100% Black paint job, Clear Side Marker Lights
Stereo: Alpine 855, Infinity Kappas all around, Infinity 150x2 amp (POS), Infinity Perfect 10 in hatch.
Pictures at Here
ICQ: 1437212
AOL: normalmatt9

 

Yea I understand all too well about mismatch components causing a lack of power but geez I cant understand what would make these and other cars around here so slow. You can only blame so much on high altitude. As for tunning I can understand some lack of power from this but These two cars my friend has are bolth apperantly in tune, start fine rev cleanly but HP isnt there. Did the builder retard the timming? IS the distributor of a few teeth? With 500$ of ignition stuff why does the one car flutter at 4,500rpm? An edelcrap 600cfm should be plenty to feed it to 6000rpm and you can only blame so much on valve springs.
As far as the LS1 goes I lined up against one the last time I was at the track he ran a pathetic 15 something and I ran 13.3. That was the first time someone ever flipped me the bird for loosing at the track.
SSC

EDIT: Im asking these questions because I told him I would help go through the chevell engine or help build "build more like it" a 454 for that car. I need some advise on problems to look for. I dont want to get to carried away especialy since im helping for free.
SSC

[This message has been edited by SSC (edited August 27, 2001).]

 

you may want to try a bigger carb. 600 cfm on a 350? that's what I run on my 305, and it sounds like your engine needs to breath more. Try a 750 cfm or 800 even, that should be of benefit to you, at least in my opinion.

 

I'm confused, what are you running that gives you a 13.3 there?

 

I personaly have no problems making a fast car thus stated in the post. All my vehicals run very well

As far as the carb, 600 cfm is the standard around here for a SB. I beleive the track Pueblo motor sports park is at 3800ft above sea level. Less air means a smaller carb must be used or elese your just wasting gas. Dont get me wrong a lager carb can be used But IMO its not worth the hassle.

Higher altitude is tricky to run fast in but it can be done. My 85 camaro has a 355, flat tops 4valve relief pistons "not really flat tops huh?", 58cc heads from the original Lg4 mildly ported, stock valves, comp270H cam,"comp270H being my cam of choise for all 3 of my v8's including the lg4 in the fbird" comp springs, 1.6 RR, Wieand stealth holley SA670, 2.5 Dual exhuast w32in glasspacks, MSD6al<--IMO junk, blaster 2 coil accel distrubutor, good old 8$ fuel pump , turbo 400<-- lazy butt still havent hooked up the electroic downshift 1800 stall converter 3:42 posi in the rear with the option of the 3:73's if I want a good smoke show. I could possibly break into the 12's If I used headders and poped for some slicks.
A total of 5800$ including the price of the car.
Thats how one runs 13.3 Money and alot of it, although this has been aquired over 2 1/2 years.
SSC

Edit: I know this is alot of stuff to make an engine run yet my friend paid 6000$ for his 355 and accesories mostly chrome junk but still there is alot of performance parts under that hood as well yet still no go "nova's in spanish= no go heh, guess its true"
SSC

[This message has been edited by SSC (edited August 27, 2001).]

 

Engine power is all based on physics, to make power you have to get air in and then air out. Well if you put a cam in the engine for 6500 but the heads wont flow past 5000 you have screwed yourself. If you run an auto with a stock converter and a large cam you will have noting off the line and it will feel very slow. If your heads cant flow it wont run worth ****, if the cam dont match the heads it wont run good, If the valve springs are garbage you will get valve float and it will run bad.
--- There are endless variables to discuss but it all comes down to one thing, and that is matching everything a specific power band in which the car runs---

dont forget physics, air+fuel has to get in the more you get in the more ignights. The more twisting force is applied to the crank and the more power is made, then the burnt gasses have to be expelled, to start the process again.

------------------
82 Z28 have LG4-305"
Rebuilt heads-3 angle valve job,ported and gasket matched. comp cam xtreme energy 262 edelbrock performer, chevy 1.6:1 roller rockers,MSD6AL, rebuilt carb,15x4" K&N
3"flowmaster american thunder, Mac high flow cat,headman headers,
700-R4--B&M shift kit, B&M tranny cooler.
Sub-frame connectors, boxed lower control arms and torque arm. 1.5" front sway bar, new BFgoodrich radial T/A's--215/65 front 255/60 rear
RADIO-- premier Deh-p300
2-10"kicker SPLs,ZR240,premier 434x(4 way), custom built fiberglass box for subs. pioneer 6X9 & 4X6, grant GT steering wheel

 

Well, then I'd say you've explained "why"...you have a 350 that runs well, so the other guys issues must be in either the build or the tune.

From your post topic and stating your times, I'd just assumed that you had either a small displacement engine or a larger displacement engine..than the 350..I was gonna yawn if you said you had a 383...and applaud if you said you had a 305

 

Eventualy Im going to build a budget 305 very high compression engine NA and see if it goes also looking for mid 13's, but it will have a 3:73 behind it.

My firend is droping the car off today so I can have a look at it. It needs an oil pump so I will check to make sure it is a 350 were dealing with here. This car peters out a 4k totaly dead. To me that indicates lack of fuel, totaly screwy timing or funked up secondaries. I will post my findings later.
SSC

 

What about traction, gearing, and stall speed? Those make a huge difference also.

------------------
82 Camaro:
350
Erson cam, ported heads,Comp Cams 1.6:1 rocker arms
Edelbrock Performer RPM intake, Holley 600
Crane Hi-6 ignition, Accel supercoil
TH350 tranny with 2500 stall.
Eibach Pro Kit
SLP 1 3/4" headers

 

True yet this car cant turn engough RPM to be usefull.


Heres the 411 on what Ive got so far. Stall 1200. Rear 3:08's. Engine 4 bolt truck 78 according to moretec. I havent checked heads yet.
timing chain is dead on & distibutor is also.
Carb appears to be working fine looks like a fNord stock carb so unknown CFM at this time. I wonder if I can blame anything on the M/T valve covers so I can keep em
Well guys got any opinions so far on what could be wrong? Im leaning toward screwed up heads at this point any confermations?
SSC

 

If this things flat at 4000 it may have a weak ignition. If it has an HEI, I'd put in MSD's module and a four cylinder coil. I think the module is PN 8360 but wouldn't swear to it. My next thought would be cam too big. With the 1200 converter you can't go too much on the cam. Also, if the cam's too big and you have stock springs, they are probably already junk even if they were new when it was built.
There are several other areas to look but that's a start.
Later,,, drt-rcr