News:

It appears that the upgrade forces a login and many, many of you have forgotten your passwords and didn't set up any reminders. Contact me directly through helpmelogin@dodgecharger.com and I'll help sort it out.

Main Menu

Engine upgrade overload. Help for a newbie, please

Started by Zentelis, July 20, 2006, 11:08:18 PM

Previous topic - Next topic

Zentelis

First I gotta apologize for starting yet another thread about these basic questions.
I've spent the last few days researching "bolt-on" upgrades..particularly Carbs, intake manifolds, headers, and cams. (I guess cams aren't really bolt-on..)
Most of the research has been done here :) I've learned alot, but I still have questions. (I'm trying to learn, I really am!!)

Carbs: Vaccume secondaries seem to be the way to go: heavy car, street gears (3.55 SG), low-end power. But, my car is a manual and every comparison between the two has said mechanical seconds are better for manual tranny's. So which factor is more imporant?
I'm looking at the DP 4150 800cfm w/mechanical secondaries, and the 4150HP 750cfm w/vaccume secondaries. According to the carb calculator, 90% VE would require a 767cfm carb..but that's if I even reach 90% VE :) %85 requires ~730cfm carb.

Intake: Dual vs. Single plane. I've read that dual is good for low-end power, single is good for high-end power. But if I go with a dual, I'd be splitting the carb's CFM, so wouldn't an 800cfm or 850cfm carb be better for a dual-plane manifold?

My head is literally swimming in confusion right now. I thought I had everything worked out, but not anymore!
Anyway: Here's my wish list with the choices:

Holly 4150 Double-Pumper 800cfm w/mech seconds
or
Holly 4160 HP 750cfm w/VS

Edlebrock Performer RPM dual-plane Intake
or
a Single-plane intake?

Engle K56 cam (I couldn't find "K56" on their website, though)

Hooker Super Competition 1 7/8" headers

Flowmaster 40's 3"


Overall, I'd like to get into the 12's on the dragstrip, but I'm not sure if my wishlist would accomplish that or not?

Thanks guys..believe it or not, I have learned alot so far! :)

deputycrawford

Let us know the engine size, if its stock and the vehicle it is in. You mentioned the drag strip. How often are you planning to be there? Is it a 90% street car and a 10% strip car? (like most of ours) Give us all the info you can possibly give us and we will give you an edumacated guesstimation. I done knowed my english is gooder. Welcome to the hobby.
If it ain't wide open; it ain't running.        Rule number one in motocross racing: Pin it; row the gear box; and wait until you hit something.     At work my motto is: If you need me, call someone else.

Zentelis

woops..I feel stupid. I forgot the simplest part of the equation  :icon_smile_big:
It's a rebuilt 440 out of another '68, but the guy I bought it from didn't know anything else about it.
My car's a '68 Charger R/T..stock engine, as far as i know.
It's a standard 4-speed a-833
I just put 3.55 SG gears in the back.

dodge freak

If you go with a DP go with a 750 hp , they come both ways -vacuum and DP. The 12's huh, well not sure but would think 3.91's would be the better choice. I would think the vacuum carb would be better with 3.55 but you want the 12's , you won't get it with that, unless its built very good. Not stock, it won't. DP carbs need gears , a hot spark  , headers , a hotter cam . Offy makes good single plane manifolds , I have a high rise 360 that has ok low power great mid range power , they also have race single planes, so do Eddys but theses are for race motors. Eddy's rpm dual plane is a good and it can go to 6500 or so. The heavy cars like vacuum carbs but with the right stuff a DP might be ok but no more than 750 I think.

dodge freak

Those flow masters make more noise than power-look for a true flow muffler. One the you can see though end to end.

deputycrawford

There are many that can answer your question but I'll take a stab at it.
I would run an Edelbrock Performer RPM intake for its dual plane design. It will give you great part throttle response and lots of drivability in the low rpm range. Its large plenum volume will give you great upper rpm range. You should never have to rev a 440 over 6500 rpms on the street anyway. With a 4 speed you could run a mechanical secondary carb. Your size will depend on you head flow and cam. If you have stock 906 heads with no porting or valve job, and the 3.55 gear, I would keep it to a 750 Holley HP, or my favorite, the Barry Grant Demon carb. As for the cam? Give the engine a cylinder pressure check and ask Chryco, Firefighter, or many others what would be a good selection. The Engle K56 hydraulic cam is mentioned often. Comp Cams makes a good "High Lift" series cam. I had a custom Engle made. My  :Twocents:
If it ain't wide open; it ain't running.        Rule number one in motocross racing: Pin it; row the gear box; and wait until you hit something.     At work my motto is: If you need me, call someone else.