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Wilburn
19-05-06, 04:55 PM
Hi,

Had my Cobra less than 2 weeks (now 450 miles on the clock!), engine is a 383 stroker 450bhp but it has now developed a cough when I put my foot down at around 2,000 rpm - it hesitates for a split second then coughs and then accelerates.

I wondered what the problem may be?

I was thinking of getting the engine tuned/tweaked when it has approx 1,000 miles on the clock.

Paul

dave
19-05-06, 05:48 PM
Hi Paul.
It sounds like you might need stronger secondary springs fitting, we can sort this as soon as there is a break in the clouds.......Tomorrow if you like.

Wilburn
19-05-06, 06:59 PM
ah! cool, thanks Dave :-)

wilf
19-05-06, 07:38 PM
Wilburn - resist the temptation to give it any serious welly until you have had the mixture checked on a rolling road.

Too lean and WOT = expensive breakages.

At 450 miles you have enough miles under it's belt to get it tuned. It will stand WOT for a while on a rolling road without problems, so long as it has been running reasonably, wiothout any overheating problems.

There are those who believe that "running in" is a waste of time anyway........

conrod
19-05-06, 07:49 PM
WOT?

I'm guessing "Wide Open Throttle"?

wilf
19-05-06, 07:58 PM
Correctamundo.

Big Thirsty
19-05-06, 10:32 PM
Wilf,

We insist on a 500 miles run in period !

Ian

Big Thirsty
19-05-06, 10:33 PM
Wilf,

Sorry, should have said that I firmly believe in the benefits of a running period.

Ian.

Clarkson
19-05-06, 10:40 PM
20 mins cam break in on a chassis dyno is good enough for me and I don't have any problems! used and abused is the best thing for it, thats a fact!.

Clarkson
19-05-06, 10:44 PM
Read this!!!

http://www.mototuneusa.com/break_in_secrets.htm

Clarkson
19-05-06, 10:52 PM
Hi,

Had my Cobra less than 2 weeks (now 450 miles on the clock!), engine is a 383 stroker 450bhp but it has now developed a cough when I put my foot down at around 2,000 rpm - it hesitates for a split second then coughs and then accelerates.

I wondered what the problem may be?

I was thinking of getting the engine tuned/tweaked when it has approx 1,000 miles on the clock.

Paul

well if its got a real 450hp, then me thinks the motor has quite a large cam and your feeling the effects of it. Other wise it's running lean and you will need to richen it up a bit.

dave
20-05-06, 07:22 AM
Read this!!!

http://www.mototuneusa.com/break_in_secrets.htm


Nice one Dave. I'd been trying to find this again on the net since my last PC died, Daryl (Fastco) had sent me a link to it before.;)

Paul's engine had be run on an engine brake and was ready to go straight away but must just need the secondaries calming down a tad.
I think today might be out though seeing as it's p1551ng it down.:mad:

conrod
20-05-06, 07:45 AM
"I think today might be out though seeing as it's p1551ng it down.:mad:"

Sunshine and blue sky down south this morning ..... :)

V8 BJC
20-05-06, 08:02 AM
Its raining in Crawley :mad:
And i'm off in a minute to pick my car up after a couple of weeks TLC.

Will be a slow drive home me thinks :(

conrod
20-05-06, 08:16 AM
Hope your fuel guzzling problem is now sorted Brian.

Clarkson
20-05-06, 11:03 AM
Its raining in Crawley :mad:
And i'm off in a minute to pick my car up after a couple of weeks TLC.

Will be a slow drive home me thinks :(



When is the next meeting V8 BJC?? Hope you car is all well!.:)

paulzxcvbnm
05-01-08, 11:40 PM
Hi Paul.
It sounds like you might need stronger secondary springs fitting, we can sort this as soon as there is a break in the clouds.......Tomorrow if you like.


Dave, did this fix this?
(I assume you are refering to valve springs)?

I have the same problem and need a fix!

dave
06-01-08, 08:49 AM
Dave, did this fix this?
(I assume you are refering to valve springs)?

I have the same problem and need a fix!


Hi Paul.
The hesitation before a sudden burst of power is usually caused by the secondary cholkes on the carb opening too soon. On a Holley there are a range of springs that hold the secondaries closed until the engine has built up enough intake vaccum. If they open too soon the engine takes a big gulp of air without enough fuel, and coughs. Too strong a spring and the secondaries either open too late or not at all.
Yup, it was the fix.(stronger spring fitted);)

brian twigg
06-01-08, 09:04 AM
I was going to suggest "Tixilix" for the cough till I saw how old the post was,


sorry,

but I keep getting a message across the top saying it's a long time since I last posted on here, so I thought this a harmless opportunity to get rid of the message for a while.

I'll get my coat shall I.


Brian.