[Meangreen]

I got a few questions to ask in one thread. Please be pateint and answer my questions... Thanks..!!

1. I am running a 350 with a edelbrock 1406 carb, comp XE274 cam,roller rockers, springs to match, stock heads with 3 angle valve job, kb domed pistons, headers, flowmasters...etc... My question is.. Do i need the edelbrock tuning kit for the card to get it exactly right.......IOW would i see any benefit in performance by tuning with the jets and primaries and springs?

2.Would it be possible to run aiplane fuel in my car, seeing as tho i live next to a private airport?

3.Would a vaccume canister help out with that hard to push break pedal when its hot out side?

4. What kind of change would i notice if i switched my ignition from msd stock coil to one of those msd boxes...and what all would i need to get to hook a box up to my stock distributor, or does it just piggy back on my system i have now?

[Siggy_Freud]

The 1406 carb was originally designed as more of an economy carb and could definitely use an upgrade.

If your car flies I would definitely recommend airplane fuel lol. But seein as how most cars stay on terra firma Id stay away from it. As far as I know airplane fuel is designed for high altitude situations where the air is much thinner. If you arre going to go with some more extreme gas Id use Race fuel which is different than airplane fuel.

A vaccum booster might help your problem yeah. Id get a guage and see where your vaccum is at after its hot.

MSD boxes are great for quicker throttle response. After about 3000RPM they stop giving you the extra spark as they cant keep up with the engine speed. For the most part they piggyback onto your system but you will do a tad of wire splicing.

[lust4speed]

Vacuum should be the same no matter how warm the engine gets. Sounds like you might have some other problem if you loose vacuum as it warms up. I'd look for a vacuum leak before spending money on the canister.

The jetting kit is a good deal compared to buying parts separately. Most people probably only use the jets included in the kit, but it is nice to have so many available to choose from.

Do a search on AV gas. We have had several heated topics on that and don't need to go there again. Let me answer in a more generic form. Run the lowest octane gas you can get away with for producing the most horsepower. Check the latest Hot Rod Magazine article on the pump gas GM 572. They lost 5 HP when they switched to racing gas. If you don't need the higher octane, save money and go faster without it. (And be sure to stay away from that high altitude AV gas, it's just a matter of time until they ban aircraft from coastal airports).

[Meangreen]

Well i went and started it this morning and drove it and the pedal was hard just as soon as i cranked it up. I think it is just because of the cam. I had pretty good vacume before i switched to the XE274 ( i was running a 270H magnum).

Would I notice the added throttle response of a MSD box?

And what all do i need to adjust my carb the right way? Like a vaccum gauge is all or what?

[killerformula]

1406 should be fine, edelbrock carbs are decent (I don't like them that much but its a personal thing) and shouldn't cause any problem on your car, it DOES NOT need an upgrade.

Tune your carb, this should have been done within the first week of running it, they all need tuning, nothing works right out of the box (despite edelbrocks' claim). I find they generally run rich on mild motors.

Ignition will help, but you'll notice it even more if you tune your carb.

Get a vacuum can, 274 is lumpy enough to warrant one.

K

[Ghetto Jet]

I pretty much agree with everything that has been said here. Before you start tuning your carb with the kit make sure you read the edelbrock manuel a few times, it will make it easier on you.


Mike

[Meangreen]

So the MSD, Mallory, and other boxes like that will hook right up to my stock distributor?

I tuned the carb. I would just like to do it more precisely with tools. I only did it by ear and RPM's.

[lust4speed]

Sounds like all you have done so far is to set the idle speed and idle mixture screws. This will have nothing to do with full or part throttle mixture. The size of the jets alone control the full throttle mix, and the size and taper of the primary rods along with the jet size will control part throttle mixture. Did we mention that it is not easy or quick to get the jetting correct? You either use a dyno, or make timed runs with one set of jets, then change jets and make another run. You do this over and over until you arrive at the optimum jet sizes.

While the MSD will just about hook to any triggering method, the points are a weak link. They wear rather quickly and this changes the dwell. Most of the point sets available today start to float and introduce sporadic spark breakdown as low as 4500 RPM. Getting rid of the points eliminates the weakest link in the system.

[Meangreen]

Its not points, Its like a stock HEI distributor with a MSD coil and accel wires.

Is a distributor re-curve kit something good to have? I have never checked my over all timing? Is this important? Should i get a timing tape and do it?

[Tmod]

If you drive on the street and don't own a pro street vehicle you can gain from a distributor recurve kit.

I personally like to limit the total centrifigual advance and add in more initial.

You end up with the same total but you have the extra advance at idle and down low.

Also you can tune the vacuum advance for your liking.

[lust4speed]

Not a bad idea to check maximum timing. What you will find is that the timing advances rather evenly up to about 4400 or so RPM, but then remains even for several hundred RPM, and then sneaks additional advance in as the RPM increases from that point. The problem is that the HEI uses the shape of the weights to limit the advance. They advance okay until the end point of the weight contacts the anvil which stops the advance, but with enough RPM the weight finally rides up on the point and advances even more. The trick is to find out what the advance is at your max RPM, and this is much safer to do on a distributor machine where you can spin the distributor up or past the redline of the engine. Last one I ran up on the machine advanced a full 6 degrees past what we thought was maximum advance at 3,000 RPM, and these final degrees all came in between 5000 and 5500 RPM.

Also, sometimes it helps to keep the advance a little slow with todays lousy gas. We used to get everything in before 1800 RPM, but now find that it helps to slow it down to all-in by about 2600/2800 RPM to avoid low speed detonation. If you buy the kit, use the kit springs with the original weights. The soft steel in the aftermarket weights seem to wear quickly and screw up the advance.

[78 chevy truck]

does your engine run pretty good with that combo but i have a 750 holly vac and bored 60 over

[killerformula]

Originally posted by 78 chevy truck
does your engine run pretty good with that combo but i have a 750 holly vac and bored 60 over

wait, are you making a statement or asking a question? Punctuation.

Capitalization.

Speak freaking English dude!

K

[Meangreen]

So vacume can- Yes
Mallory ignition box- Yes
Distributor recurve kit- Yes
Timing tape for balancer- Yes

So i decided not to get the carb tuning kit. Why? Because it would be hard for me to see if it made any difference switching to certain jets and what not. I guess i could use one of those G-Tech things but i am not sure how accurate those are?