Joined: Tue Mar 12 2013, 11:31AM
Location: Germany
Posts: 70
Greetings,
I have a 1974 Newport and already asked some things (engine swap, new brakes etc.) after all that I realised, that I am good with my 400. It was originally a 2bbl engine, with the 2 bbl camshaft. Now I have an Edelbrock Performer Intake with a Carter Thermoquad, which runs nice. I rebuilt the suspension of the car and it really drives nice now. But i would like to make it faster. So what would you guys think is the easiest and/or most logical thing(s) to do?
Joined: Sat Mar 29 2008, 03:36PM
Location: North eastern Wis.
Posts: 1638
Read all you can get your hands on pertaining to these cars. Tune-ups basically very a bit by car and equipment, as well as year. Each car will have it's own idiosyncrasies. It will take some practice, and patient s to learn. Once you've got the hang of it, the sky is the limit. Get the distributor dialed in, add dual exhaust, and a hotter cam. Basic stuff really. Have fun and keep us appraised of your fun.
Joined: Fri Mar 13 2009, 11:21AM
Location: San Marcos, CA
Posts: 713
If the car has 2.7X or 2.4X gears in it, swap them out for 3.2ish, that will make it feel much quicker. If the main jets are 92s, swap them out for 95s and if the secondary jets are 115s put in 125s. dual exhaust and recurved distributor (as mentioned) will help a bunch. don't go overboard with a cam, that can hurt low end and our big cars need excellent low end torque (higher stall converter and low gears will make up for a big cam if you want to go that way). Adding compression (milling the heads) will help quite a bunch too. I put together a stock 400 with a set of closed chamber heads (915, very rare now '67 440 GTX) and it ran 14.6 in a stock '69 roadrunner. My $.02
"Get the distributor dialed in, add dual exhaust, and a hotter cam. " Good advice.Getting the advance in quicker will make a difference in seat of the pants feel.Good plugs,wires,cap,and rotor if needed. Past those basics you have to spend some money.Cylinder heads with a smaller combustion chamber to up the compression(ported a plus or aftermarket even better)coupled with a smallish(building for torque here)cam will make a huge difference.Just don't over cam it(easy to do with a heavy car with highway gears).
Joined: Tue Mar 12 2013, 11:31AM
Location: Germany
Posts: 70
I already switched to dual exhaust. With one glaspack (cherrybomb) for each side. Nothing more. But original exhaust "manifolds". should I redo my original heads or buy new ones (which ones). I would like some more bottom end. I don't need high top speed. I wanted to make a list with good parts. So which gears and cam would you recommend?
I also want to get a redone Thermoquad from rockauto for the "highpowered" version. may redoing mine with the bigger jets is better?
I would consider some 440 source(or similar) aluminum heads with a closed combustion chamber of 80cc or less to help compression.Bear in mind you can have a perfectly fine running engine with your stock heads though I would recommend new valve springs if you change the cam.Replacing the heads with ones that flow better will increase power everywhere. An Edelbrock Performer intake manifold(383/400 are the same) A Lunati Voodoo 10230700 or 1023701 would be good choices.Get a new timing chain as well.Degree the cam in. Your thermoquad is fine if in good running order and may/may not need to be jetted up. Down the road some Hedman shorty headers and the required small starter would be a nice upgrade.
A dual snorkel air cleaner or open element air cleaner would be an upgrade over the single snorkel setup.
Glass packs would be the last muffler I would choose but all that matters is that YOU like the way it sounds.
For a strong Vehicle that accelerates as if it is late to a date - I would select the best information that was given and take into the fact of your Vehicle Regulations and Inspections .
The Factory's Duel Snorkel Air Cleaner Housing is the best of The Air Cleaner hints.
Using 235 x 75 x 15 Radials has a reason. Black Walls was the most sold style and every Police/ Pursuit Tyre is with Black Walls.
The Voodoo Camshaft is a copy of The Factory's Cam Shaft ( called number CS-327 ).
The Heads that came with all 1972 - 1976 400's or 1976 - 1978 400's are copied in aluminum by after market vendor's.
If you change your Compression Ratio to higher number's past 9:1 --- you will need a Higher Costing Fuel. The Lawn Mower Gas that you may be using now will need to be replaced.
Joined: Tue Mar 12 2013, 11:31AM
Location: Germany
Posts: 70
Does the engine need some pressure from the exhaust system? With the glasspacks now, there is almost none. Here in germany there is no gasoline under 95 ROZ / 85 MOZ. But I mostly use gas with higher numbers.
I have one of those aftermarket Air Cleaners. The original one is missing.
Some of the info helps a lot some things are the same, what I already had in mind. What metering rods should I use on my TQ? I also read on the internet about putting a 383 crankshaft in a 400.
I need some more information about dialing in the distributor perfectly, degreeing the cam in (break in?) and the gear change, monaco has mentioned.
I now have some really big 275/40 20 wheel on it. But I want to change it to 245/60 15 in the front and 285/60 15 in the back. But that is mostly for the look.
I have to say "THANK YOU" for your help. It is exactly what I was searching for.
Joined: Tue Mar 12 2013, 11:31AM
Location: Germany
Posts: 70
I just learned that the octane designation differs in the US. So our lowest gasoline would be 90 AON. The next one (that I sometimes use) is 93 AON. Is that ok? And can I get some benefit out of it with dialing the distributor?
Your engine was purposely designed for the lowest level of Octane/ AON sold. To use something that has a higher rating ( and related cost ) does not raise the engine's power. If you "feel better" and do not mind spending extra money for this -- then do it.
The larger width of tyres that you have place a increased strength usage/ need on your steering and front suspension parts. The parts wear from this is liked by shops that replace and sell these related parts for it keeps them in business. This is a fact and has nothing to with "looks".
Those Chromed Air Cleaners pass warmed air that happens to be under The Hood Area of The Engine Bay. On an Dyno this will show that your Power Ratio is now lower. If you are striving to get a better Fuel Usage at an even ( constant ) 2200 RPMS - then The Chromed Unit that "looks so good" is functioning correctly. There must be a reason these have not been used by major manufactures since about 1966.
The Snorkel used with Air Cleaner Housings has a Ram Effect which is learned in The Bernoulli's Principle. The second part of this is Cooler Air Molecules permit A Higher Engine Power than warmed ones.
*** A related subject is having a Warm Up Choke and all related parts that function properly. The sooner a engine is "Warmed to its Operation Temperature" --- The Power is increased ---- The Fuel Usage is lowered and etc. ***