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-   -   Lethargic/pathetic/anemic 302 observations … (http://www.clubcobra.com/forums/all-cobra-talk/134245-lethargic-pathetic-anemic-302-observations.html)

Davekmd 08-04-2015 08:54 AM

Lethargic/pathetic/anemic 302 observations …
 
2 Attachment(s)
The 302 motor in my 2003 SVC is pathetic. I paid a shop over $400 to fully inspect, perform routine maintenance, service, and generally make sure the car I was purchasing was ready for the 2nd owner (me) so I was a bit surprised to find the following. See pics (I hope they attached).

Yes, that is one COMPLETELY clogged air filter. It is so black and clogged that even a halogen light won’t shine through at any level. It would appear that’s the original air filter from 2003… Notice also the clear tubing vacuum hose. It’s mostly collapsed at ambient temperature and when the engine gets hot the tubing deforms and collapses completely. So the motor can’t breathe and when hot can’t pull vacuum to advance the distributor. Wouldn’t a PERFORMANCE SHOP look at those things before passing judgement the car was fully serviced and is ready to roll? Wouldn’t they fire it up and say, hmmmm this motor doesn’t want to rev and runs like a dog?

Wouldn’t they make note the clutch is ridiculously stiff and absolutely unacceptable for an essentially stock 302? And wouldn’t they test drive the car drive and find the brakes are essentially useless? Wouldn’t they run the car for a few minutes? (as soon as it arrived at my house and was started, got warm, it puked anti-freeze all over my driveway.) Basically the car was not street worthy when delivered to me. I’m attending to all of the issues but I’d be feeling better had I not forked over $ for the service work. The work was performed based on the recommendation from the shop, 500 miles from my house, where the car was being sold from. Ergo I didn’t come to pick the car up and learn firsthand about the work done or not done…

I’m replacing both the air filter and vacuum hose, hoping these are the major culprits for the poor performance. The other strong belief I have is that I need to change out the 600 CFM carburetor. According to my old school background this motor (5,500 RPM) can’t use more than 400CFM…

I hope to pull the tranny this weekend and gather the information to sort out the clutch problem. If I can I’ll completely disassemble the calipers to inspect them for corrosion or rust, etc. I got replacement parts on order…. Sorry for the bi^ching. I feel better now.

Onward! Dave K.

DAVID GAGNARD 08-04-2015 12:03 PM

Looks like your on the right track to get the engine/car sorted out......I'd never use that shop again and make sure your friends don't either.....sounds like they did pretty much nothing for the 400+ bucks you paid them..........

Had a friend recently asked me to look at his 9.9hp outboard motor...it wouldn't idle and was very hard to start...he had just recently paid a shop 250 bucks for a tune-up (2 spark plugs) and to clean out and adjust the carb,I think it ran worse when they were done....that was 2 very expensive spark plugs!!!!!!!!!!!!!!!!
Took me less than 2 hours to take the carb off,dis-assemble it and go thru it and re-assemble it and put it back on,adjust the carb and throttle linkage and basically go thru the whole thing.......he told me it had not run that good in years....

I just can't see how some of these so-called mechanics sleep at night doing the things they do.......but that's just me....

david

Jim Vander Wal 08-04-2015 06:25 PM

No reason that the 600cfm carb won't work but it may need a rebuild which is easy. Heads, cam, RPM will all contribute to the proper carb size. Then plugs and wires, cap & rotor possibly. The trick will be finding someone to tune it.

Don't start throwing out the main components until you've determined that the replaceable pieces don't need to be changed.

Jim

Jac Mac 08-04-2015 07:47 PM

Vac advance on comes into effect at cruise/part throttle mode, however if its hooked up to wrong port on carb it may be getting full advance at idle & if your $400.00 mechanic did not realise this and set advance at idle with it connected your car will not be getting full advance on the road under power. Disconnect & plug advance tube then check ignition timing at idle ~10°/12° should get you started, then run up to ~2500+ and check your getting something like 30°/35° total advance to check dizzy mech advance for starters.

347stroker 08-05-2015 12:03 AM

You have a PM

347stroker 08-05-2015 12:05 AM

Dave you have a PM.

DanEC 08-05-2015 07:02 AM

Another reason I do as much as possible myself on my cars and use a repair shop as absolute last resort. As long as you have a vacuum secondary Holley on the car there's no reason to change it - although it may need a good rebuild and going through to check for evidence of Bubba modifications.

cycleguy55 08-05-2015 11:25 AM

Quote:

Originally Posted by Jac Mac (Post 1358056)
Vac advance on comes into effect at cruise/part throttle mode, however if its hooked up to wrong port on carb it may be getting full advance at idle & if your $400.00 mechanic did not realise this and set advance at idle with it connected your car will not be getting full advance on the road under power. Disconnect & plug advance tube then check ignition timing at idle ~10°/12° should get you started, then run up to ~2500+ and check your getting something like 30°/35° total advance to check dizzy mech advance for starters.

Correct - disconnect the vacuum hose from the distributor and plug it before checking timing, then un-plug it and re-connect it once your idle and total timing has been set.

BTW, there has been much confusion over manifold vacuum vs ported vacuum, with people in both camps. After spending way too much time digging in to this issue it became apparent to me the use of ported vacuum started at the beginning of the emissions era and is not suitable for most engines in Cobras. I'm firmly in the manifold vacuum camp, that's what I'm running on my BBF and it seems to like it - the idle is smoother and the idle speed increased about 150-200 RPM after hooking up the vacuum advance to full manifold vacuum.

Ported vs Manifold vacuum: Carburetor Question - Vintage Mustang Forums

YouTube video: [ame]https://www.youtube.com/watch?v=UInmE9hg8Rk[/ame]

Gaz64 08-05-2015 01:01 PM

A hose sucked flat like that gives a delayed operation in BOTH directions.

Delay in advance application and more importantly delay in release of vacuum advance when under load.

The air filter shows the engine was strangling for air with the collapsed pleats.

DAVID GAGNARD 08-05-2015 03:55 PM

Quote:

Originally Posted by Gaz64 (Post 1358126)
A hose sucked flat like that gives a delayed operation in BOTH directions.

Delay in advance application and more importantly delay in release of vacuum advance when under load.

The air filter shows the engine was strangling for air with the collapsed pleats.

+1, basically you need to go thru the engine front to back and check out everything......if you don't have the knowledge/time/tools to do it, find a friend that does or make friends with someone that can help you out........

I'm betting a "basic" tune-up,plugs/plug wires(?)/air filter/set the timing correctly/vacuum line/etc./etc. will make a world of difference in how your engine runs!!!!!

David

Davekmd 08-13-2015 11:29 AM

1 Attachment(s)
Yep, I'm surprised to have found so much in need of repair given such glowing reports about the car from the shop and payment to go over the car ... Yes, the underside was clean as described, but the car needs work. Replaced the collapsed vacuum hose. Replaced the air filter, swapped out the 600cfm carb for a new Edelbrock 500 CFM 4bbl. The plugs were horrible so I'm replacing them. The way the shop was talking this thing was fresh as a daisy. Live and learn. I haven't fired the car up with the work completed as the plugs aren't in. We'll see if the motor wakes up a bit.

Moving onto brakes and seats next. Have no master cylinders and Hawk HPS pads. Got the seat rails. Here's a pic of the engine bay as it sits today.

Davekmd 08-13-2015 01:53 PM

Opsss have THE new master cylinders and Hawk HPS pads...

Blas 08-13-2015 07:51 PM

I see only a single carb linkage return spring. Two would be preferable.

cycleguy55 08-13-2015 09:35 PM

Quote:

Originally Posted by Blas (Post 1359079)
I see only a single carb linkage return spring. Two would be preferable.

Agreed - redundancy on that little item is important.

Davekmd 08-18-2015 06:08 AM

Yes, I'll get a smaller diameter one to go through the one in place or I'll mount one at the front of the engine and pull the throttle closed from the front. I'm taking a timber framing workshop (2 weekends) so I'm not getting a whole bunch done of the car right now...


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