Load Exhaust Ser III

I recently overhauled my 2,25 motor but the head job may have been a bit
dodgy.
My exhaust makes a lot of noise when I put the accelerator hard with little
acceleration.
It has been getting louder but the exhaust is a recently fitted s.steel
freeflow which someone tells me gets louder as it wears in?
At engine idle the exhaust pressure seems pretty high when holding my hand
near the end of the pipe.
How do I tell if my compression is blowing past the exhaust valves into the
exhaust?
By the way the pipe burns nice and light brown on 97 octane leaded.
Any ideas?

Cheers
James Cape Town

jamsan wrote:

> I recently overhauled my 2,25 motor but the head job may have been a bit
> dodgy.
> My exhaust makes a lot of noise when I put the accelerator hard with
> little acceleration.
> It has been getting louder but the exhaust is a recently fitted s.steel
> freeflow which someone tells me gets louder as it wears in?
> At engine idle the exhaust pressure seems pretty high when holding my hand
> near the end of the pipe.
> How do I tell if my compression is blowing past the exhaust valves into
> the exhaust?
> By the way the pipe burns nice and light brown on 97 octane leaded.
> Any ideas?
>
> Cheers
> James Cape Town
To test if the exhaust valves are leaking, test the compression. The
simplest test is to turn the engine using the hand crank, checking that all
four compressions are the same. At the same time, stop on each compression
and listen for hissing in the exhaust. To be slightly more exact, use a
compression gauge in the spark plug holes, turn the engine by starter and
check for close to the same pressure in each cylinder, again listening for
the sound of a leak into the exhaust.
I think it is unlikely that you have a leaky exhaust valve. If a valve were
leaking badly enough to increase noise from the exhaust, I would expect it
to be running noticeably roughly and to be noticeably down on power. In
addition, the noise would normally be most noticeable when idling.
JD

jamsan wrote:
> I recently overhauled my 2,25 motor but the head job may have been a bit
> dodgy.
> My exhaust makes a lot of noise when I put the accelerator hard with little
> acceleration.

Give the thing a damn good tune up. Plugs, points, condensor, rotor,
cap, leads, then set the tappets, timing, idle speed & mixture. The see
how it goes.


> It has been getting louder but the exhaust is a recently fitted s.steel
> freeflow which someone tells me gets louder as it wears in?

Any freeflow system (especially one with headers) will sound noisy - the
freer it flows the less noise it will stop. Stainless exhausts tend to
resonate more than mild steel ones so will sound louder. It still
shouldn't really be an issue - my 2.25 has a 54mm mild steel exhaust
with one 'performance' muffler and is not noticeably noisier than
standard. Incidentally said mild steel exhaust is now about 10 years
old and still hanging together - I wouldn't waste the money on a
stainless system unless I was regularly on salted roads (which I doubt
you see often in Cape Town).


> At engine idle the exhaust pressure seems pretty high when holding my hand
> near the end of the pipe.

Sounds normal - at an idle of say 700rpm it's pumping out well over
1000l/minute of gas. If the pipe is 54mm diameter (and my maths is
correct) then the exhaust gas will be travelling at about 20kph as it
exits the pipe when idling - that will give the impression of pressure!


> How do I tell if my compression is blowing past the exhaust valves into the
> exhaust?

Check/set the tappets (as above), then do a compression test or a leak
down test. If the results look good you'll have to start looking for
the cause.

> By the way the pipe burns nice and light brown on 97 octane leaded.
> Any ideas?

Pipe colour is basically meaningless on unleaded - about the only
inference I would draw from this is that it's not burning oil.


--
EMB

I thought they got quieter as they 'wear in' due to being a bit more sooted
up?
Have you also put a k&n type air filter on? If so, you may need to adjust
the mixture, what colour are the spark plugs after a run ?
Richard

"jamsan" <[email protected]> wrote in message
news[email protected]...
>I recently overhauled my 2,25 motor but the head job may have been a bit
> dodgy.
> My exhaust makes a lot of noise when I put the accelerator hard with
> little
> acceleration.
> It has been getting louder but the exhaust is a recently fitted s.steel
> freeflow which someone tells me gets louder as it wears in?
> At engine idle the exhaust pressure seems pretty high when holding my hand
> near the end of the pipe.
> How do I tell if my compression is blowing past the exhaust valves into
> the
> exhaust?
> By the way the pipe burns nice and light brown on 97 octane leaded.
> Any ideas?
>
> Cheers
> James Cape Town
>
>
>