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Discussion Starter #21
Don't worry too much about timing marks at this point..Just turn the distributor and the engine will tell you what it likes..It should idle good,start good and have quick crisp acceleration...Being a tooth off only applies if you physically cannot turn the distributor body to get you the timing you need...This is usually caused because the vacuum advance is hitting against something...
Yeah the only reason my vacum advance isnt hitting the radiator hose is cause i dont have the canister on right now or it would be. So i think im still a tooth off but i can deal with that later i just wanted to get it driveable.
 

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Discussion Starter #23
The Main reason an engine will die after you Tap the throttle and rev it a bit then let it drop back to idle is from the Vacuum advance being engaged at idle and dropping off when you goose it then it not catching up when the base idle is reached once again.
Yeah that makes sense but i dont have the vacuum advance on right now. Besides that mine was back firing really loud threw the carb as soon as i would tap the throttle and it would die immediately
 

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Yeah that makes sense but i dont have the vacuum advance on right now. Besides that mine was back firing really loud threw the carb as soon as i would tap the throttle and it would die immediately
Without the vacuum advance canister on the dizzy the vaccum advance probaby is moving at random and screwing up your timing. Reinstall it and reset the diizzy at top dead center so timing can be set without removing the the canister. Then try running it without the vacuum adv hooked up

Another hint is vacuum advance dosent work that well unless your engine is equiped with EGR provisions. I spent a year with a car with adjustabe vacuum and springs and a bunch equipment. The best I could do is 1 MPG better than without it. When it was right for in town pinged on the hiway right on the hiway wrong in town.

Might do some good locking out a MSD and using a programable 6 series with a 1 bar map sensor. Have all that in my posession but havent hooked up the map sensor yet. Might not as I am not all that excited about their drop timing method.
 

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Discussion Starter #26 (Edited)
What carb should i go with? my setup is in the first post in this thread.


Would a holley 670 PART #: 0-80670 work good? also, are there any benefits to using a double pumper?
 

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Discussion Starter #27 (Edited)
heres some pics of my build so far. btw my interior is far from finished just got the cd player installed and amps wired up. Go easy on me this is my first build.
 

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I have a Edel AVS 650 on my 331, it's make 440 HP at the crank.

According to my builder it is more then enough.

So, a 650 or the Holly 670 should be fine.

BTW, very nice ride you have there. That Mazda should be a blast to drive!


Jet
 

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Stroked Out 7 – Congratulations on being able to drive your car around the block! It’s a huge step in the building process. Nice looking build too. With the advice given here, we’re sure you’ll get it running better soon.
 

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Discussion Starter #31 (Edited)
Well I dont know much about the heads, I bought them from my machinist. He said another customer had him do all kinds of work to them and the guy never came back so he gave me a good deal on them. There cast iron i know that... compression on the motor is 9:5:1 I belive. I'm using the stock rear end for now, its got 4.10's. If you need to know anything else just let me know. I think a 670 holley would work good, i'm just not sure if i want vaccum or mechanical secondaries and if I want a double pumper? Thanks for all the replies everyone! been lots of help

On there website they have a carb selector after entering all my info it suggested 650, 670, 750 and a 770 cfm carb. Should I go with something higher then a 670?
 

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Generaly vacuum secondarys are used in heavy vehicles that are under powered. Provides more low end torq. Another reason would be my 460 Ford dualy plenty of power but with a double pumper pulling my 14000 lbs trailer the Cruse control vacuum motor isnt strong enough to open the secondarys on a steep hill. Vacuum secondars are often better for fuel economy although it can have a lot to do with the operator.

Holley recomends using mechanical secondarys on lighter vehicles and using a CFM rating one step down from calculated or picked off the graph in their cataloge.

A big reason I also ask about your cylinder head flow has to do with proper selection of cam, intake and carb. Mixed with what the vehicle purpose and owners desires. Open track, drags, street strip, street.

Selecting a carb for your setup I would also recomend one with changeable air bleeds to get the best tune .

I also notice your fuel pressure regulator on the fire wall. Some sanctioning bodys dont allow it and most manufactures state in there mounting instructions not to mount there.
Need to rehash your stuff will be back for some suggestions
 

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Would like complete cam specks... cranking compression check.... who did the head work? BTW I will be in Indy early eary this next week.
 

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Discussion Starter #35
I didnt know that about mounting the fuel regulator but i just read threw the instructions that came with my BG regulator and it didnt say anything about how to mount it. I'll have to check with my local track and see what there rules are, but thanks for the info. If I have to move it I will, not that big of a deal I guess.

My cam is a Comp Cams PN# 31-452-8. Im looking at the cam card that came with it im just not sure what specs exactly you need. Like I said this is my first build, thats why I have so many questions. Im pretty good at doing the work just not so good at all the specifics. My machinist works at Highland East Auto Parts in Renton, Washington. I had the heads flow tested I just cant remember the exact number. I'll call him and get it tomorrow.

On the Holley website it says your car should weigh less then 3100 lbs, have a true min stall of 4000 rpm and have a min 3.73 rear end ratio for 3 or 4 speed autos before you use mechanical secondaries. I know my car weighs less then 3100lbs and I have 4.10's but i'm not to sure about my torque converter all i know for sure is thats its a TCI. The guy told me its 1000 rpm above stock. So whats stock?

Right now im just using a edelbrock performer intake, I'd like to get a new one but I dont have room for anything taller. Dont got the hood clearance. Also, I do plan on taking this car to the track but I want to be able to drive it on the street too. So street and strip i guess. I'll get more info on the heads in the morning. Let me know if you need anything else to figure out what carb i should go with, thanks
 

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nice looking build. when I read the first post you made, vacuum leak came to mind first. also going from flat to roller cam your firing order may have changed, check your cam card for the firing order. but you are prob rolling around town by now. let us know what all you found to get it right, your solution could help some one else.
 

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Thats a really cool looking car you got there & as you can see your in the right place for good info.
My old build was just like your motor, with the same cast iron heads that had been cleaned up, but specs on em, i never knew. A holley 670 is plenty for that motor with vacuum secondaries for a street car, easy to maintain, better fuel mileage & mine at least, was near perfect right out of the box. I to chased vacuum leaks, timing issues & as stated above, just try look after one issue at a time. Once i got mine driveable, & to a good shop for a tune, they found a leaky intake gasket on one bank, that was the whole source of all my issues! With a good tune that little motor ran so nice, couldn;t believe what a good tuner got out of it.
good luck & keep us apprised,eh
 
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