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Author Topic:   Wont go
Whitelightning
Member
posted September 24, 2003 01:46 AM
OK her we go. Have a old k5 blazer that had stock 350 in it that runs like a champ, so I get this brite idea to put my camel back heads,big cam something like a 500 lift(cant exactly remember),roller tip rockers,victor jr intake and a 850 holly double pumper, headers,and guess what it runs like junk now. You have to put it on the floor just about to get it moving, I really dont know what to do, timming is good and has been moved all around from 30-40 and no difference, what could it be could it be tha valves to tight, or the carb, I have not run that carb in a long time but it was very clean. ITs just dont run good at all


ctfarm
Member
posted September 24, 2003 07:23 AM
Double check your cam timing,it may be a tooth off.If thats OK you may need to go with a smaller cam.Big cams on low compression motors don't work very well.If this is an early to mid 80's model with electronic spark control the module or spark control module could be bad.



ctfarm
Member
posted September 24, 2003 07:24 AM
quote:
Originally posted by ctfarm:
Double check your cam timing,it may be a tooth off.If thats OK you may need to go with a smaller cam.Big cams on low compression motors don't work very well.If this is an early to mid 80's model with electronic spark control the module or spark control module could be bad.




ctfarm
Member
posted September 24, 2003 07:28 AM
One more thing,the 850 is too much carb and you probably need to put on a duel plane intake.The Victor jr. doesn't work well at low rpm's on the street.



wizzard
Member
posted September 25, 2003 12:24 AM
Ok you have several things hurting you here.. low compression stock motor, combined with big cam and single plane intake= very very poor low rpm torque..combine that with a hevy vehicle and I am guessing big tires.. and that is why you have to floor it to get it to move. The carb doesnt help any either...way too big and vacuum secondary would work better.
You first need to change intakes and carb if you can, then depending on how much work you want to do either increase compression, or more easily change cams, or increase rear end gearing.


BrianW
Member
posted September 25, 2003 11:48 AM
Have you checked the obvious Vacuum leak?? Also have you run a compression test and checked the vacuum at idle? Could be rockers were installed too tight?? (causing low / no compression)

It sounds like it's got too little compression and too big of a cam... Try leaning out the carb a little bit. If you're intent on running that combo try swapping to a 3000 RPM stall converter to get the engine up to speed first.

Does it run OK or good when it gets up in the RPM range?

Whitelightning
Member
posted September 25, 2003 08:18 PM
it dont really run worth a dang but it does level out after it gets up to upper rpm, its really my buddies vehicle and we plan on working on it this weekend, I think its just the wrong combo but I could be wrong,cause the heads have been cut way down and it still has the stock 4 eyebrow dish pistons and I just dont think the thing makes any compression. The heads came off a 383 strocker that would really make some power but it had pop ups, and the cam came from a circle track engine, its a reeves cam but he is not sure the exact numbers but it like a 500 lift, so I am thinking alot of wrong combanations


dirtbuster
Member
posted September 25, 2003 10:07 PM
Try this. Depending on how much work you want to do. Leave the heads on they should increase compression and should flow better over the stock heads. Change out the cam either put the stock one back in or one similar to it. Say around 200-210 duration @ .050 or so. Then either put the stock intake back on or get a good aluminum dual plane intake, and a vacuum secondary carb. Headers should be ok.

What is killing you is the big cam with the single plane intake. That combo wont make any torque at low speeds especially with low compression. On a heavy vehicle like that you need torque not top end power.

RentOcrew
Member
posted September 26, 2003 12:49 AM
What size exhaust do you have past the headers? Try running it with open headers and see if that wakes it up. Good Luck


Whitelightning
Member
posted September 26, 2003 03:36 AM
yeah we been running it with open headers and guess what we only have been pulled over by the law two times hehehe, Imagine a big k5 blazer with the top removed and big 44 super swamper boggers rolling down town with open headers boy do we attract attention, It might not run but its gotta be the loudest dang thing I have ever heard in my life hehehehe I thing we gonna change cams and I guess we will have another intake cut for those heads cause the been angle milled and all that other stuff, and put the old quadrajet back on it until we can do better I will let u know what happens


Mud Boy
Member
posted September 26, 2003 03:27 PM
ok put a 3310 holley on it it does run alot better, think I am gonna put a 3000 rpm stall in it that should solve everything lol


dirtbuster
Member
posted September 29, 2003 11:58 AM
If youhave a set of stock wheels and 28" tires around throw them on and see what difference it makes.. I think youll find a huge difference. The 3000 converter will help but if you can get a little deeper gear in it it will help all around with your big tires. Or once you get the thing moving try holding it in 1st or 2nd gear to keep your rpms up.


wizzard
Member
posted September 29, 2003 10:48 PM
I'd put an r.v. type cam in it or at least a cam that is made for low end torque and deffinitly get your gearing down where it needs to be, 44's are a big jump.


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