[bodydroppedsquare]

OK I built the motor in my truck and its running alot slower than I thought it would.. does this seem right??? its a 350 4 bolt flat tops over 40 with 487x heads milled 10 lunati 60102 cam 1.6 roller rockers rpm performer intake 1406 carb stock manifolds accell ignition module msd cap coil th350 transmission stock converter with 308 gears and 22 inch rims in an 86 chevy shortwide... I figured the thing would run at least low 15's high 14s but the best i got was a 16.5.....

[DENCOUCH]

Truck + 3.08's.

I bet you have some MPH & ET there awaiting, if you ditch the 3.08's

[F-BIRD'88]

The head flow sucks, the compression ratio is too low, the stock exhaust manifolds really limit power and torque, the gearing is way too low, the converter stall is too low.

swap on some small combustion chamber heads. Ported 305 heads with bigger valves work very well on a low budget. Use a thin head gasket too.
Get some long tube headers. 4.10 to 4.56 gears and a 3000 stall converter.
get a 750cfm carb.

[bodydroppedsquare]

the truck is bagged so I can't run long tube headers but shortys would be better than nothing. I'm wanting to put different gears in it but the truck is going to be daily driven so I think the 410s would be a lil bit much. I'm also looking around for different heads. would you recommend a holley or edel carb???

[bodydroppedsquare]

I'm also not quite sure on the gears but i'm pretty sure they are stock...

[TroyBoy]

A TCI Breakaway converter (2200-2500) or similar would work well with 3.73 and not put you at too high an RPM .Like you said about the headers,shorties are better than stock.Those heads are one the best flowing smog heads made.Yes, I know you could buy aftermarkets but not everyone has that kind of budget and if frogs had wings,they wouldn't bust their butts when they jumped

[poncho62]

Its a heavy brick...........You need a lighter body....maybe an S10

[bodydroppedsquare]

Originally Posted by poncho62

Its a heavy brick...........You need a lighter body....maybe an S10

Yea but I'm not trying to make a drag truck I'm just wondering why the truck only ran a 16???

[HalfOunce]

Theres no replacement for displacement . Go big block or 500caddy. A 500cad isn't much heavier than a small block chebby

[poncho62]

Originally Posted by bodydroppedsquare

Yea but I'm not trying to make a drag truck I'm just wondering why the truck only ran a 16???

There are 2 ways to go fast......More power or less weight......Less weight is cheaper.

[lanierledford]

Troy,
could you be mistaken, I think the frog should be fine when he jumps. But when he lands, now there might a some concern as to him well being.

[red65mustang]

4500lbs and 300HP (stock exhaust manifolds and your CR?) is about/roughly a 14 (with a strong tail wind at sea level)....

calculator link:
http://www.tciauto.com/Products/Tech...alculators.asp

it's a very long list of possible/probable (minor and major) causes that are likely acting together to make your ET so so slow....

my first test would be to do a compression and/or vacuum test to verify the whole rotating assembly is working properly, rings and valves are infact sealing....
(a 16 indicates next to no HP power if the motor is the problem)

one small item is the 1406 carb is set up more for (lean) economy as delivered (98/95 jets 75/47 rods, it wants 5.5psi fuel pressure max), you are likely too lean WOT=.2-.3 slower???

edit add:
another effective way to test how well the rotating assembly is sealing is mount a vac guage so you can read it driving....
on a 3rd to 2nd downshift at 50mph your motor should read about 25Hg....
here's a link on how to diagnos the rotating assembly with a vac guage (caution they are referencing typical stock motor readings results)
http://www.users.bigpond.com/ergoff/vac1.htm

[Charles_426]

1- Be sure your throttle is opening all the way. Have some one hold the pedal down, and look at the blade(s) (engine NOT running) .
2- Basic tuneup - Is there slop in your distributor? Chevy distributors are bad about having too much wear vertically, between the drive gear and the housing. I have heard that each thousandth of movement changes your timing by 1 degree. Moroso makes shims for this (cheap fix) Shim kit is PN 26140. If your distributor is then too tall, bottoming on your oil pump,it may cause spark scatter. Use PN 26150 to space the housing up off of the manifold a little.
Is your engine running on all cylinders. I had a 455 Olds that was arcing one cylinder, only under power. I had a friend power brake it and saw the spark plug wire arcing to a vacuum hose.
3- Is your fuel system up to snuff? No kinked lines, if it has been sitting, check your fuel tank vent (darned dirt dobbers). If you are running good on the first half of the track, but not picking up at least 15-20 MPH on top, look hard at your fuel system.
4- Does your truck roll fairly easy? Check for brake drag, have the alignment checked.
Hope this helps, Charles

[454C10]

what was the trap speed?

How much total ignition timing?
Done any carb tuning?

A "350 hp" engine out of tune can easily lose 100 hp.

22 inch rims doesn't mean anything. How tall are the tires?

Your cam is about 10 to 15 degrees too big for a truck with a 3.08 gear. Drop a few sizes on the cam and it will go faster.

My c10 (4500 pounds) runs high 14's at 97 mph with a set of 3.08. It has a 468 cid engine (exhaust manifolds, 206/212 degree cam, 8.75:1 cr, some head work).

Takes around 380hp to make a 4500 pound truck run 97 mph in the 1/4 mile. And a 380hp 454 big block can use a 3.08 gear. A 380hp 350cid needs at least a 3.73 gear.

Maybe you should consider using a 4.11 gear with a 700r OD transmission. Comes out to be the same gear ratio on the highway.

[TroyBoy]

Troy,
could you be mistaken, I think the frog should be fine when he jumps. But when he lands, now there might a some concern as to him well being.
You are right. Point taken