Too many problems with it. Its brand new and should be puttin out well over 300 horse. Its a 350 with a 750 carter carb. All it does is bog. If i try and accelerate too hard i here a pop and it wants to stall for a second. I was on the highway and started to accelerate gradually more and more and all of a sudden my engine revs like its in neutral so i let off and then it was fine. One of my rocker arms knocks against my valve cover on the passenger side. This is just turning into a nightmare. I need some help.

 

I would get rid of the carb. I would get a projection throttle body kit or something of the like. If that is not an option I would go definetely with a smaller carb.

If you are running just a cam my opinion is that you are overcarburated and running rich. Without knowing more details 600-650 is better suited for your application.

I would also check your distrubutor and make sure the timing advance mechanism if functioning properly. Is your ECM still in control of timing?

 

make sure your idle fuel adjustment screw is set right. if it is a holley it should be the screw on the front driver's side of the car. mine was adjusted so i got way to much gas. this caused me to run really rich and bog all the time. it made one of my sparkplugs messed up too. i adjusted the screw and replaced the plug and i have had no problems. there was that time there for two weeks where i wanted to strap a c-4 explosive to my car and and watch so cool fireworks though good luck though

 

#1 Your car is not tuned. TUNE IT.
#2 If your tranny acts like it is in neutral when it is in GEAR then your transmission if on the fritz and will not be around much longer. Get it checked out.
#3 Adjust your rocker arms. If you are cruising around when you know you have loose rocker arms then you pretty much deserve anything else that occurs.

It's only a nightmare if you can't do anything about it.

 

Well the thing is i have had it tuned twice, once by a mechanic and another time by my friend and now im gonna do it again with another buddy of mine. The rocker arms were adjusted by a mechanic and he told me my valve covers might be too small and thats why its hitting. I just got new axels, 3.73's, and a posi unit put in my rearend... would that have anything to do with it doing what it did on the highway?

 

Usually when a transmission acts like it is in Neutral on the highway it is because of internal problems. It sounds like it may be time for a rebuild.
There's more to tuning an engine than just fiddling with a/f mixture screws. No motor runs perfect when you first get it running but it's nothing time and patience won't cure.

Good luck.

 

alright thanks, yeah i never expected the stock 700r4 to last long anyway with the new motor... lata

 

Check the fluid level in your tranny. Could be low and your stall isn't getting the proper fluid. Happened to me, filled it up and it was fixed.

You have WAY too big a carb for your application. I've got a 650 holley that puts out 300 horse. No problem, and there is still room to add gas. Sounds like your flooding out. Have you tried putting larger metering rods in?

Sounds like your rockers are adjusted wrong. If one is hitting your valve cover, and the others aren't, then it's not adjusted right, not the valve cover height. Sure it's not just tapping, rather than hitting the cover?

What kind of rockers? If you have a high lift cam, you are probably binding on the rocker stud nut... and you'll need long slot rockers. Summit sells a set under their name for $40 something.


That pop could be a back fire, it could be you have an intake rocker too tight so when it fires it comes through the carb also... Are you timed right and does your advance work?

 

Well the motor is rated at exactly 375 horse, i just said well over 300 cause it sure doesnt feel like 375 but i havent really been able to step on it hard. But 750 too much for 375? I will check my tranny fluid that may be it. Im pretty sure its hittin the valve cover cause you can feel it, i'll have someone readjust them again. My timing is good too so that is fine. I'll look at jegs about what you said. Thanks.

 

So what is this motor? What is it built out of?

How many horsepower is this "crate" said to be responsible for? Just coming in a "crate" doesn't mean anything as far as how it will run.

A 750 carb is plenty for a 350; too much if it's not built out of parts that will allow the engine to produce meaningful power at any RPM that requires that much flow.

Bogging, and backfire from the carb on acceleration, is usually caused by a lean condition, not a rich condition.

Tuning isn't something you do "once" and then "again". It takes some time. It means setting up the distributor's timing curve to make the motor run the best it can; selecting and adjusting carb parts for best results; etc. etc.

What kind of distributor is on it?

 

Ok, well i will keep trying. The distributer is an HEI with hp advance curve

 

So what motor is this? What parts is it built out of? Where did you get it? Who put it in the "crate"?

 

Guy in arizona. Its got flat-tops, forged rods, clevite lifters, the worst heads ever.. i gotta get new ones. THey are the 882's. Single plane high rise intake. Hydraulic flat-tappet Crane cam, 480/480 lift. I dont know if i should have bought it now. I did back in november when i didnt know much about engines and asked a couple people if they thought it was good and they said yeah. And then i realized after i bought it that it had those ****ty heads on it. So thats why its not gonna reach 375 horse.

what do u think would be good heads to get, dart iron eagles? Like 200cc, 220cc?

 

Dart heads are nice as far as that goes. I wouldn't go past 200cc. Several people have got the Pro Topline ones, they seem OK for a little less money.

Yeah, I know what you mean now about it being gutless, I'd be real surprised with the combo you have, if it even makes 275 HP. That's pretty much a mismatch from Hell.

That intake needs to go; that's costing you an unbelievable amount of power within the engine's usable RPM range. An intake like that is a net power loss at any RPM below about 6000 RPM; and that old "Stage 2" cam won't let the engine run up there anyway, and the heads certainly don't either. Major mismatch.

I'd suggest a set of good heads, as described; a dual-plane intake, such as a ZZ4 or Performer RPM; and a modern cam, such as a Comp XE262.

 

those same heads are responsible for allowing a 400 c.I.d. motor to make a whopping 175 h.p. at the crank. you'd be lucky to be making 250 h.p. with those heads.

are you sure you don't have a rocker stud pulling out of the head, that will cause the valve to never seem to be adjusted right.

the combination of the single plane intake (high rpm suited) and the 882 heads (boat anchor suited---low rpm heads) are probably really hurting your performance.

 

alright, thanks man

 

i might as well just send back the motor, and get my money back since i know what im doin now. Get something worth my money instead of puttin all into something that is junk.


Im lookin at this

http://www.enginefactory.com/stroker.htm

 

Where did you get that engine from? You should post so others can be ware. Again, 750 is too much for that setup. Try testing with a qudrajunk. I am sure you can get one free.