Mechanics' some HELP

[bambamtama]

Mechanics\' some HELP

I am running a 383 under the hood...new block, heads, etc. but the carb is a rebuilt.
The problem is the action of the traction. When I'm in 2nd and start traveling it's alright, but when I shift into the next gear (3 speed manual) it seems it lost almost 1/4 of it's power and it like starts to jerk, Like it's not getting sufficient power. Would it be my distributor and spark plugs? I have a ACCel distibutor on it...what are your suggestions to the matter. Thanks Guys!

 

[tRustyK5]

Re: Mechanics\' some HELP

Do you have a tach? If so, what rpm are you shifting it at? It sounds like you're lugging it...

The SM465 is pretty wide ratio, so when you go from second (3.58:1) to third (1.70:1) the rpm's drop about 50% and so does power unless you shift at a high enough rpm. From third to fourth (1:1) it's not quite as bad but still bad enough.

When I still had my 350 I'd shift at 2800 rpm most of the time, which would drop it down to 1400 or so in the next gear.

Rene

 

[bambamtama]

Re: Mechanics\' some HELP

Thanks Rene, I was also thinking too, that maybe my gear ratio might have some effect to it(rear axle)...no? yes?

 

[R72K5]

Re: Mechanics\' some HELP

what axle ratio do you have ? and what rpm range did you build engine for ? and what rpm range do you usually run ?

 

[tRustyK5]

Re: Mechanics\' some HELP

Tall gears will make the problem worse, although I drove my Jimmy with 2.76:1 gears and 33's for quite a while...

Rene

 

[bambamtama]

Re: Mechanics\' some HELP

will tghe engine was replaced with a new one. They took out the 350 and put in a 383(350 with a 400 crank 4 bolt main) and so I really haven't tested the compression and the timing yet. BUt I'm running at 600 rpm idle. I'm still running he factory gears with 33's what would you recommend? For those size of tires?

 

[Confedneck]

Re: Mechanics\' some HELP

33s? if its a 700r4 everyone here will tell you to run 4.10s or 4.56s.. but if its more of a daily driver you could go 3.73s
chevy4wd has a 700r4, 3.73 gears and 33" all terrains
i have a sm465, 3.40 gears and 33" wild countries
he has more top end and better economy... but i have more low end due to the transmission gearing..
it all depends on usage.. /forums/images/graemlins/thumb.gif