throwing parts at a problem without thinking is less than smart

[grumpyvette]

I had two long time friends stop by and ask my opinion as to why franks 1967 chevelle just was not running as well as they thought it should be, now these guys are long time hot rodders, but engine builders and tunners they are NOT!

both these guys have cars that are more SHOW than GO!

I just wish I could get a car to LOOK as good as these guys can!

but tuneing and trouble shooting sure escapes thier expertise.

anyway I ask whats wrong, and they can,t tell me other than to say the cars missing and not running correctly, they are basically clueless as to the cause and have swapped carbs, distributors,(three times)set the timing,(more times than they can remember)ETC. and can,t seem to nail down the problem.

they ask me to take a look..........now the cars got a crate 502 bbc, replacing the 325hp 396bbc that came in the car, and its got headers and a crower solid lifter cam, 850cfm holley and a rpm air gap intake, and what they assure me is a stock 1967 distributor.(dual points cast iron, mechanical tach drive, LOOKS to be a 67-68 corvette dissy to me)

 

first thing I find is that the nicely labled plug wires are arcing to the headers in two places, and the ohms meter reads over three thousand ohms on two so they need replacing, and that the plug gaps vary from .045-.070

while Im checking that I do a compression check and Im not all that impressed with the numbers but they are semi reasonable so I let that slide for now, I do a valve lash check and they are in need of adjustment.(BADLY) seems they have not set the lash since the solid lifter cams install over 18 months ago :smirk:......... the valves set, I check the timing and its jumping all over, seems they forgot to seat the rotor correctly, and the brass tabs bent sevearly and the screws holding it are loose ., pulling the distributor and checking the slack, I find I need to add a new distributor gear, its worn,(looking at the cam gear it seems far less worn) AND shims as its got almost 3/32" vertical play. while I do that I talk them into getting a pointless electronic conversion kit. I install that and the new wires/plugs all gapped at a CONSISTANT .045.

next I check the carb,its float levels to high in the rear and too low in the fron,t, that gets adjusted and I test for vacuum leaks......yeah, they had one, gasket gets replaced and intake re-tested, it now passes. next the timming gets set..its now remarkably more consistant :smirk:

anyway, a hours trouble shooting and a few parts replaced resulted in some very happy campers.....especially since they had been screwing with it for two LONG WEEKENDs prior to bringing it by with little success!

the reason I bring this up, is that durring the whole process , they constantly kept insisting it was a flat cam lobe or a jumped timing chain,or a cracked cylinder hear ETC.

NOT ONCE had they dropped back to the basics and set each and EVERY component to its ideal setting and checked that each component was working as designed....no! they were convinced that it needed a new (NAME YOUR FAVORITE PART HERE, THEY WERE SURE IT WAS ON THE LIST)

GUYS I see this stuff frequently,if you cars not running correctly find out WHY, don,t just start installing parts randomly and expect things to get better!

[dr_hunt]

Well, seems that nobody changes thier own oil so that's not really a suprise. Tuning is almost an art. It's really forgotten, really it is. Name the parts you are supposed to change in a tune up. Everybody always forgets the PCV valve. I doubt anybody really measures spark plug wire resistance anymore anyway, just buy new wires, they probably needed replacing anyway, at least that's what they think. If they ever put a vacuum gauge on the intake to adjust the carb, they would have known they had a vacuum leak in the first place or at least would have been more likely to suspect that. But how did they adjust the idle on the carb without one? Go figure! Plugs, you mean they don't come pre-gapped from the manufacturer? Get out of town, first I've heard of that, what will they do next to screw the do it yourselfer? Oh, and don't forget that just because plugs are new means that they are also good. Don't forget reading plugs either, but then that leads to jetting, power valves, metering rods, accelerator pump cams, squirters, air bleeds and that whole can of worms, better to take to to insta-tune and let the flunkies do it right. End play on the distributor shaft is bad, crap. Timing, what about total advance and when it gets to full advance, really nobody plays with timing unless they go dizzyless and even then they just plug in some curve that looks good and go with it. Valve settings, do they really have an effect on things, like make it run better on top or provide more low end? You are saying that they should be all the same? What's .010 between friends these days?

 

Used to be the day when we had to tune every week, cause those of us who remember dual points and solid lift cams as being the hot setup, know that you had to really tune it every week, not once a year or two.

 

Sorry, grumpy, I'm feeling grumpy, cause the whole world has the credit card tune attitude and pocketbook to back it up, but in reality they are missing the essence of hotrodding and undoubtedly will get whipped at the strip by a lessor engine that is properly tuned. I hate to see a good engine go to folks like that just cause they can afford it.

 

What about tuning plug gap for best ET, nobody probably has ever taken the time to do that or play with timing the same way either.

 

Your right grumpy, tuning is a complete waste of time, kind of like changing oil, don't like doing it so let's just get bigger heads and more carb. Oh, by the way, what will they do when the plastic is maxed out?

[Guest ON3GO]

well i dont use a PCV, carb, afm, etc...

which i guess makes tuning either easier or harder, but im with you guys 100%.

at my job (which i repair/fix cars) we always check the basics and then work our way up. but funny thing is sometimes we forget and it ends up being the easiest and basic thing thats wrong on the car.

 

what i would like to know that maybe somebody can answer is this..

 

how can we check for vacuum leaks? i heard of the smoke check but its not the easiest thing to do say if your at the track or etc.

is there any other ways thats easier and smarter to do?

vacuum leaks are always most the the causes why most the turbo cars come into my work.

 

mike

[dr_hunt]

I'd answer that but then I'd be giving away all my secrets.

[Sparky]

 

how can we check for vacuum leaks? i heard of the smoke check but its not the easiest thing to do say if your at the track or etc.

is there any other ways thats easier and smarter to do?

vacuum leaks are always most the the causes why most the turbo cars come into my work.

 

mike

 

fill the intake system with water and the pressurize it, you can hook up a shop vac on pump, or you can just start the car and floor it till she builds boost. the only problem with the latter is the fact that the entire system must be filled to the top with water, including the intercooler, this can make starting the car very tricky. some people address this issue by sticking a garden hose near the compressor intake and running the car off the rev-limiter, while it works for some, results of course may vary.

 

good luck!

[grumpyvette]

"how can we check for vacuum leaks?"

 

yeah the way I find vacuum leaks on carb intake manifplds isclean and easy with no mess. get a propane torch,

 

http://akamai-lq.bizrate.com/resize?sq=400&uid=328841952&mid=111419

 

(DONT LIGHT IT) just SLIGHTLY open the valve so its allowing gas to flow at a low voluum,start the engine and let it idle at the lowest speed you can then place the tip of the UNLIT torch at any suspected vacuum leak and listen for the rpms to increase and watch the tach, gas flowing into a vacuum leak will increase engine speed.

[dr_hunt]

Damn grumpy you had to go spill the beans, starting fluid is what I use, with the little long plastic tube that you use on WD40 cans. Really anything flammable will work, just do little spurts and use in well ventilated area. Just propane and starting fluid leave no mess. Hairspray leaves a mess.

 

Is it wet in Fla yet grumpy? Seems you've had your share of rain this year.

[Cody 82 ZXT]

Damn grumpy you had to go spill the beans, starting fluid is what I use, with the little long plastic tube that you use on WD40 cans. Really anything flammable will work, just do little spurts and use in well ventilated area. Just propane and starting fluid leave no mess. Hairspray leaves a mess.

 

 

I personally like carb cleaner. It's great but, you have to be careful around painted parts.

[grumpyvette]

carb cleaner,wd 40,lighter fluid, hair spray,starter fluid, ETC all pose either a fire hazard, potentially destroy paint, stain aluminum, or leave a residue, the propane torch tip leaves zero residue and and potential fire (unlikely) is instantly extinguished by simply turning OFF the propane flow from the torch

[Cody 82 ZXT]

carb cleaner,wd 40,lighter fluid, hair spray,starter fluid, ETC all pose either a fire hazard, potentially destroy paint, stain aluminum, or leave a residue, the propane torch tip leaves zero residue and and potential fire (unlikely) is instantly extinguished by simply turning OFF the propane flow from the torch

 

I agree but, I think the biggest thing here is that you just have to not be an idiot when useing these products. Like many things with cars you have to think about what your doing.

[Guest ON3GO]

what about vacuum leaks for us turbo guys?

AKA.. boost leaks.

[dr_hunt]

I think there was another thread where somebody claimed you filled the intake system with water 100% and then run the engine off the rev limiter.

[Sparky]

I think there was another thread where somebody claimed you filled the intake system with water 100% and then run the engine off the rev limiter.

 

OK I was totally kidding in the above post, I honestly hope that nobody took that seriously!

[Cody 82 ZXT]

I think there was another thread where somebody claimed you filled the intake system with water 100% and then run the engine off the rev limiter.

 

 

On this type of thing I once had a customer that got carried away with throttle body cleaner so much that he hydro locked his engine. I didn't get all the details but, he was pretty embarrassed. It was one of thoses akward moments when I really had to hold back on laughing or making any gooffy comments to him.

[BrandonsZ]

GUYS I see this stuff frequently' date='if you cars not running correctly find out WHY, don,t just start installing parts randomly and expect things to get better![/quote']

 

ASE Certification would also help. there used to be ROP courses in high school which they would open to the public, maybe not anymore.

[johnc]

I see this all the time too.

 

Customer's car is handling like crap and he brings it in wanting me to install a coil over kit to fix it. I fix the broken anti-roll bar mounts, replace bushings, align the car, and then ask the customer to drive it. He is ecstatic and says the coil over kit was the best thing he ever had done to the car. He questions why the bill is so cheap and there are no coil over parts listed...

[TheNeedForZ]

what about vacuum leaks for us turbo guys?

AKA.. boost leaks.

 

Make some thick soap fluid, brush on suspected areas and then wait to see if it bubbles.

[hoov100]

ASE Certification would also help. there used to be ROP courses in high school which they would open to the public, maybe not anymore.

its only open to highschool students, they now have auto couarses like that at comunity colleges

[BrandonsZ]

Someone could make a deal with the school to use the facility after hours and set up a class for adults (for a nominal fee) and kick back to the school. But if the community college is already doing that then maybe not. My HS had adult programs for Autoshop, machine shop, ceramics and woodshop, it was open to anyone, even students (they needed parental consent). They got to do all the fun stuff that they phased out of letting us do after too many accidents. I think someone cut off a finger in woodshop and the next semester all they'd let us use is hand tools (my last semester luckily). Fortunately I had already made several items the previous 2 semesters that are still in use today a nice chery wood grandfather clock and an oak sterio cabinet.