Vintage Mustang Forums banner

1 - 4 of 4 Posts

·
Registered
Joined
·
4,560 Posts
Discussion Starter #1
i have an appointment to take my 1971 mustang to a shop that uses an old sun analyzer to tune up engines. the car is a 351c-4v with closed chamber heads. a car club friend of mine took his '69 390 mach one to him and he said the guy got his engine running great. he charged about $40 precisely set the timing and adjusted the carb. since i don't have the equipment or technical expertise to do this myself (i can disassemble/assemble, but tuning is another matter), i thought it would be worth the money.

here's my question: is there anything else he can do with this analyzer that i should have him do? also, since i've had the car only a few months and don't know much about it's history, i thought i would have him do a compression test while he's under the hood. would this be worthwhile? what would it tell me? is there anything else that he could do that would either improve the tune of the motor or tell me about it's internal condition? thanks.
 

·
Premium Member
Joined
·
19,203 Posts
Sun Analyzers can spot intermittent sparks and bad wires in an instant, and tell you which wire is not up to snuff. Shade-tree mechanics have a hard time competing with that kind of analysis. Other than that, a reasonably well tuned engine in good form isn't going to need a sophisticated tool like that. I may be wrong, but for $40, it's worth a shot!
 

·
Registered
Joined
·
3,848 Posts
I'd look into a chassis dyno tune-up. It will be more $, but it is also will offer a better performance tune for your car and engine under load.

As far as a compression test goes, do a search here on the VMF and you'll get a ton of info. Search "Compression test".

Good luck.
 

·
Registered
Joined
·
6,911 Posts
I've wanted an older scope for a while....

he can check how many kilovolts (1.21 gigawatts?!?!?! LOL!!) it takes to fire each cylinder (voltage in the secondary rises until it arcs across the plugs), and in many cases what is causing the voltage to be high in a cylinder.

The nice thing about the old fashioned scopes is the truely real time relatively "hi-fidelity" display because of their analog nature....the newer crap synthesizes a display of what is going on digitally........unless it samples BILLIONS of times a second (and they don't......it's not like they have 2Ghz processors in them), it's kinda guessing the dynamics of the ignition waveform....it'll catch the really blatant probs, but I don't believe it'll give an "old timer" as much info as he can use.
 
1 - 4 of 4 Posts
Top