The Jalopy Journal
Discussion in 'The Hokey Ass Message Board' started by norms30a, Nov 9, 2015.
VERY well said beaner, and its really hard for a lot of us to adjust.
I'd replace the Qjet, it is designed to operate with much higher vacuum than that stroker can provide. It isn't an easy carb to work with, excellant for a bone stock engine. I'd replace the intake too, it is like the carb, designed for a stock application and you don't have a stock motor.
A guy at work told me his car would barely run and was going to take it to the mechanic. After I looked at it, I told him to just replace the plugs and wires and it'll run fine. The next day he told me he bought the parts, a ratchet and socket, but was just going to take it in anyway. He told me he looked at it for 20 minutes and couldn't figure out which way to turn the ratchet to take them out. After busting his balls all morning, I showed him how to replace the parts at lunch. After watching me swap out the first plug, he decided it was too hard and it was best for me to just do the other three. It ran perfect when I was done, and he thought I was a magician. The point being, my friend is a computer whiz, but has no interest in learning about cars. He just wants it to work when he gets in.
get a good tune on model A, & buy a low buck mild ride for slow cruising
Thanks for all the reply's guys I had the A out for a drive and got it good and warmed up, then I sprayed carb cleaner on the intake gaskets and yes I definitely have a vacuum leak some where. So the question is, when I replace the gaskets how can I be sure of a good seal this time, I spread Indian head gasket stuff on both sides of the gaskets last time and I have leaks, what is the answer? The ports on the heads are very large and the intake barely covers them so there will be very little gasket material to seal so it has to be good.
Squirrel, I really enjoyed watching you and your son on your road trip to the different drag strips and racing all without opening the hood...wow.
Yes, I want to learn how to tune this engine just like I had to learn body work to build this thing and paint it and I'm going to give the upholstery a shot too.
Here's a couple pics so you guys know what I'm working on since my avatar is kinda old,lol.
Exactly how much vacuum do you think his engine will produce, and how much vacuum do you think a qjet takes to operate? I have gotten these carbs to work and idle perfectly on cars that only had 6" of vacuum, and with the cam profile in this guys stroker i would expect to see no less than 10"
I've no idea what heads you have , but if they are a raised port or even a large port , be sure you're using an intake set for the heads , i.e. fel-pro 1204 [small port] 1205 [medium port] 1206 [large port] set the gaskts /manifold on dry & be sure you're covering the tops of the ports...no need for any goop on the gaskts. , toss the end seals & use a fat bead of silicone on the end walls , a light smear around the water ports helps..
w/that cam I'd expect 12-14 " of vac at idle [800 rpm]
After reading through this, the first thing that jumps out at me is a light car, lumpy cam and 2000 stall converter.
You have lots of compression, but the aluminum heads should tone down the detonation, so I wouldn't worry about that. Blueprint says the cam is 230/240 at .050 which is borderline "too big" with a stock converter and as you open the throttle blades to keep the engine from stalling you kill the adjustability of the carb. So you need a converter that won't pull the engine down when you drop the transmission in gear at idle. I've done several light cars with 3000 converters and they don't noticeably slip when driving normally. If that high of a stall scares you, you could drop it back a little but I wouldn't go below 2500 stall. In fact, I'd like to see a little higher than 2500.
And while you're at it, you need to check and make sure you have around 24 degrees advance in the distributor and run around 12 initial. I've sometimes had to bypass the vacuum advance, but it doesn't kill the fuel mileage much and that's about the only downside to not running VA.
That should put you in the ballpark to make the engine idle and start on your carb tuneup. Don't let anyone tell you that you can't make a Quadrajet scream, they are great carbs. It just takes a little work to get them right for your setup and then you're done.
^^^ What he said. Performance cam and tight converter in light car = trouble getting it to idle properly in gear at a light. Vacuum leak certainly needs fixing with proper gaskets and Permatex Ultra Black on the China walls. I tend to do a very light smear around the water ports on both sides as well but that's just me. I'd bet its 70% a tune up issue and 30% too tight converter. This 383ci is far from too much motor for a driver coupe IMO. Good luck man.
2old2fast Thanks for this info, I will not use any goop when I put in the new gaskets. I always use silicone on the 2 ends when I have an intake off, works well too.
I am wondering if there is a way to measure the head port openings once I get the intake off, so I know if I should get the Fel Pro 1206--large. There are no numbers on the heads, they just say Blueprint. Thanks.
You got a set of calipers? Just measure 'em Height/width , gasket specs. are online
I took a brand new edelbrock 600 carb out of the box, hooked it up and I didn't have to touch a thing.
Tuning with a lap top,,,
well that's just infinitely adjustable. There's a perfect spot where there is no compromise and everything is optimal. It's alot like having too many options on the menus at a restaurant, or a wine list that's 10 pages & each one is as long as your arm.
When its all mechanical with carbs and distributors there's not so much variety so its easy to pick what you want so to speak.
Check with blueprint. It should only take a min or two.
Alot of The BP heads will accept both the early 12 bolt manifolds and the later 8 bolt vortec style intakes.
The heads will have a part # that you can reference on the BP website.
I hear you about a too much motor situation as I have one in the fleet that is too much,mine is slightly different as its just too big and even though it has good manners it just likes to drink too much gas for my cheap ass. Spent all summer trying to squeeze a few more miles to the gallon out of it with no improvements other then making it not run as good,so last week I decided that if its still going to suck a bunch of gas it better run good so back on went the larger carb and is going to get tuned the way it was. I hope you are able to get it to run the way you want it too.
I wouldn't be to quick on pulling that intake until you propane for leaks.... just sayin..
Get the book from Cliff Ruggles,,If you like Q-Jets,,I also like them and use them ,Just need to know how to tune them,,,Cliff is a good guy to talk to also...
Use to be a guy in Sioux Falls that worked at the post office. Absolute magician with a carb. Last time I talked to him he was running around either his 63 Split window, or his 67 convertible... If I can think of his name I'll post up on here, but it's been quite a few years since I last talked to him... ask around at shops like Sehr Machine, they'd likely know who I'm talking about.
and let it be a mystery I need the money setting these up. it takes me 20 minutes , 5 to set it 15 to find my special screw driver .. ( or make one )
When you remove the intake, you will likely see where the leaks are and possibly figure out what caused them. Sometimes the surfaces are too smooth to grip the gaskets. On cast iron heads and manifolds, I sand and clean them and sometimes use a little battery acid to get some surface rust.
Sometimes the intake manifold doesn't fit well and you need to use thicker intake gaskets. As has been said, measure the ports and Summit has the .120 thickness Fel Pro gaskets for most port sizes if you need to go thicker.
There are also some gaskets with metal in them. Some builders that I know use the thicker gaskets on every build. I always liked to glue the gaskets to the head with 3M Black Super Weatherstrip Adhesive to make sure they don't move while setting the intake. Some builders don't use the end gaskets but I do and glue them down too. I don't like to replace them with silicone because the silicone can squeeze out and get into the engine if you use too much. If you use silicone, you need to let it set up for a few minutes so it holds together better.
A 'properly' modified Q-jet will run the engine with no issues or problems. It must have the emulsion curcuits and idle curcuits internally modified to make the needs of the engine. I have had small blocks with 262 and 274 degrees of duration @ .050 idle at 900 rpm with a properly modified Q-jet. This goes for any brand of carb, nothing out-of-the-box is going to be "spot-on"...period.
Fix the vacuum leak! then get it running as best as possible and dump the Q-jet. Good carb in its day. remember THERE ARE NO NEW ONES! Gas is a liquid. After 30, 40, 50 years of flow passages are much bigger than designed. look at the Grand Canyon as an example. Carb smaller but same effect.
This is all we use at our Hot Rod Shop on engine gaskets or where no gasket is used.
The best sealer ever.
One last thing, as others have stated, you need at least a torque convertor rated at 3000 RPM . Anything less will make the car jerky and hold the engine done. Light-car, torquey engine = more stall to "act right".
I use a TCI Street Fighter in my Coupe .....
Here is a link to their unit for a 700R4 http://www.summitracing.com/parts/tci-243105/overview/
Take your intake off and make a stiff paper templet tapped out pattern of the heads and the intake and compare. Then you will know if it will ever work. Gary
AHotRod is right, You need more converter. 3000 stall will make the car behave way way nice. TCI makes some real good converters. I run a TCI trans and converter, has held up to lots of punishment, and still comes back for more.
Thanks for all the reply's guys, so much info, going to take some time to digest it all. I want to warm it up 1 more time and spray some carb cleaner again just to make double sure the engine revs up before I tear it down. Maybe tomorrow if it doesn't rain or snow. Do local places like NAPA have Fel Pro gaskets or at least can get them the right size
The local NAPA here carries FelPro. I assume that others do to.
I've ran a 3k stall in my model a with a healthy 440 mopar and 2.72 gears.. It worked like it should etc.. I swapped out to a 2500 Hughes converter though for a little better feel at freeway flying.. huge difference but the quality converter still didn't bog at a light, great drivability. Cruising at 1700 in 3rd gear... smash skinny pedal and flare to 2500 for a second then start going up. I agree that the 2k stall is way low for that cam and car. Only saving grace to the 2k stall you have is the 4.10 and the low first gear of a 700r4.. Once you get this motor dialed in try for idle speed about 800 and it should still pull against the converter but nothing near what your were doing.
Glad you found the leaks, And I agree with what's been posted... just use a bead of the sticky stuff around water ports and corners where the valley meet head or do a complete bead for the oil valley... Remember once you fix this huge vac leak, your going to have to work on getting carb all tuned up.. Should sound way different also and I would guess that after you reved that motor up it took it a little bit to return to idle..
Your on the right track man... 2 thumbs up..
if they are Blueprints SBC aluminum heads they are LT-1 (80's version ) Ports .
"Too much engine" ........... I'm pushing 70 years old and I never knew you could have TOO MUCH engine !!
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