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rev limiter
cadebytiger - 24/4/07 at 01:59 PM

hey all.

I want to know if i set a rev limit when i was setting up the ECU. i don't have the cable with me. Am i alright to just rev the thing up to when i think the limiter should kick in with no load on. (i know this will be very loud)

i guess what i am asking is. Am i gonna blow it up or would it only blow up if it were under load

It's a pinto BTW

Rupert


ned - 24/4/07 at 02:10 PM

shouldn't blow up under no load - especially if it's what you plan to run to under load on the road but itmight make you wince a little


Guinness - 24/4/07 at 02:12 PM

I wouldn't risk it to be honest.

In my humble opinion it doesn't matter if you have the engine under load or not if you over rev it!

The things that could go wrong aren't dependant on whether it's in gear or not.

Con rod giving way, piston hitting a valve, a valve breaking, piston hitting the spark plug. All possible with or without being under load.

Best to wait until you have the lead.

Mike


cadebytiger - 24/4/07 at 02:22 PM

will wait! There is no hurry

thanks


dilley - 24/4/07 at 03:42 PM

Labouring or over revving kills engines.


TangoMan - 24/4/07 at 05:26 PM

Most engine blow on overrun as the conrods stretch as the piston passes TDC as there is no compressed mixture to assist the momentum of the piston.
No load won't change that so don't risk it.

A pinto is a strong lump and will safely rev to 7K for short bursts and I can't believe you want to rev past that!!


cadebytiger - 24/4/07 at 08:21 PM

good god no!! lol

if i set it to anything i think it was about 5 or something. Think i was quite conservative.

i think i will check the box!! lol


flak monkey - 24/4/07 at 08:27 PM

What carbs are you running?

I have mine on twin 40s and it revs to about 6,800rpm, but its run out of puff at about 6,200rpm. Its pretty much self limiting.

What block do you have? If its not a 205, then limit it to 6,200rpm. If its a 205, limit it to 6,800-7000rpm.

I think they were revved to somthing like 5600 or so in the sierras/cortinas etc.

David


cadebytiger - 24/4/07 at 08:37 PM

it is a 205 block yes. right then might give it some more beans next time i find some straight road!!

Bloody loud at just 4500!!

ps-running 45s

[Edited on 24/4/07 by cadebytiger]


flak monkey - 24/4/07 at 08:42 PM

Hehe, my grandparents said they heard me coming back over their TV (which is pretty loud as they are half deaf) when i gave dad a blast down the road last week.

You can hear mine when at home when i start it up round my grandparents (about 300 yards away).

Depending on the choke sizes you have, it will happily rev to over 7k with 45s, so would limit it to 6,800 to be on the safe side. Assuming the engines in good nick that is! I rebuilt mine, so am happy that it will take it...

David


cadebytiger - 25/4/07 at 08:21 AM

we rebuilt ours too but did not use ARP bolts. I guess i should set it a bit lower than 6800 then?


flak monkey - 25/4/07 at 10:06 AM

Std internals are all good for over 7000rpm in short bursts with a 205 block, so 6,800 should be fine. Asked about ARP rod bolts when i rebuilt mine, and was told it wasnt worth it. Only place thats got ARP bolts on mine is the flywheel.


cadebytiger - 25/4/07 at 10:11 AM

ye have heard the flywheel tends to be a problem. maybe we should have gone arp on that.

i guess this is less to do with rpm and more to do with studen changes in rpm.

We have a lightened on on there so maybe not so much of a problem


flak monkey - 25/4/07 at 10:14 AM

Yeah, the sudden changes are greater with a lightened flywheel too. (I have one on mine). Though not sure how the forces compare, as although the changes are faster, there is less weight, so less inertia.

David

PS is that you in your Avatar with the firey poi?


cadebytiger - 25/4/07 at 10:16 AM

yes it is.

All fun and games until you get yourself in the face.

Thanks for the help. Sounds like a have the rev limit set too low (that is if i have set it at all)