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TR4/4A General header question

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Dash

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Wondering if replacing the standard cast iron manifold with headers on these TR engines is really worth the expense. Seems to me you're only gaining a few inches before the exhaust from the four cylinders is once again fighting for space at the merge point on a single exhaust sytem like the TR4. Of course they look nice but is there actually any significant advantage to making the switch on a single exhaust system? Also to anyone who has done the conversion, how aggravating was the hand fitting/port matching that most of the venders say is required ?
Greatly appreciate your opinions and experience
 
I noticed a substantial difference in pick up in 1-2-3, with the mid length headers I got from BPNW.
it was a bit of a pain (and expensive) getting them fitted, as I had it done in a shop then sent the headers out for ceramic coating, then re fitted.
However, I believe it is one of the easiest ways to improve performance and power.
 
You could fit a TR4A exhaust manifold, that has the twin exit .
I welded a 2 into 1 collector to the old twin pipe flange that I cut off the old twin exhaust pipes. And then ran a single 2" pipe all the way from there.
You end up with an exhaust system similar to after market headers.
 
I had a set of headers with a full exhaust system on the 3A years ago. It was made by the foreman of a large exhaust company for his own car and it was beautifully made, fitting together without even needing clamps. However, I have stuck with the standard manifold on the 4A but with a long 2 into one system for the down pipes and no front muffler. I had the whole system ceramic coated back to the mount in the centre of the chassis.

Some of the issues you can run into are quality of the headers, matching to the ports, thickness of the flanges being different from the intake manifold causing mounting problems, clearance from the starter and potential for cracking. I think that the original 4A manifold is quite efficient and it is also a bit quieter than headers for the long trips that we do.
 
GTP1960 said:
hey Rocky, is your Holden equipped with that SS engine? The HEC 5000i?
Click to expand...
It originally had a Holden Special Vehicles 5 litre with 185kw or 245hp. Something happened to it at the last dealer coupon service at 130,000 miles and it ran all of the piston rings. During the total rebuild, (NOT by that dealer!) the mechanic rang and said he had to send my crank to be polished and balanced and for only an extra $800 we could put a new stroker crank in. After deep thought and contemplation (about 2 seconds) I said yes.

It has the stroker, a .030 overbore, a cam, headwork, chip and different headers with a twin 3 inch exhaust. The rear tyres should have Joseph Lucas written on them because smoke frequently comes out of them. It has around 200,000 miles on it now and I doubt that I will ever sell it. My staff seem happy that their 70 year old boss still occasionally leaves two long black stripes on the road outside the factory.
 
My staff seem happy that their 70 year old boss still occasionally leaves two long black stripes on the road outside the factory.
Click to expand...

Good on you. one must lead by example.
 
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