Merlin Heads

General Chat About Exhaust, Cylinder Heads, Fuel Systems And Intake

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CastleMGBV8
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Post by CastleMGBV8 »

Perry,

Thats good news, was this a without gas run or did you try it with the gas as well?

Kevin.


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ged
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Post by ged »

Hi Perry,

What rev's were you doing for the 25hp increase?

Regards Ged
mgbv8
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Post by mgbv8 »

Kev!!
The increase was nasp without gas.

Ged!
Max rpm for this test was about 5500....

I've detailed my results in the Dyno section.

I was happy with the result, but I fried my tyres on nitrous :(
Perry Stephenson
MGB GT + Rover V8
9.62 @ 137.37mph
Now looking for 8 seconds with a SBC engine
http://www.youtube.com/watch?v=nVscbPHgue0&list=UUqIlXfSAoiZ--GyG4tfRrjw

https://www.youtube.com/watch?v=eg3avnsNKrc&index=2&list=FLqIlXfSAoiZ--GyG4tfRrjw
kokkolanpoika
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Post by kokkolanpoika »

mgbv8 wrote:I just fitted a Weber 600cfm carb and a Harcourt single plane manifold to my 4.6.

My old setup was a Weber 500cfm carb and edelbrock performer 3.51 manifold.

I had to fiddle with jets to get AFR's correct at wide open throttle. But she made 25bhp more at wide open throttle on the dyno today with the new carb and manifold.

I reckon this will be a good upgrade to help MinorV8 get his power up.
So are you running ported rover heads? stage 3?

My theory. If minorV8 buts single plane manifold with his engine, he might get also same power upgrade with his old setup/rover heads? So total ingrease might be same 11hp?
:shock:
Timo
mgbv8
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Post by mgbv8 »

Timo!!

My heads are stock 4.6 with stock valves. But I have ported the exhausts myself to JE specs.
Perry Stephenson
MGB GT + Rover V8
9.62 @ 137.37mph
Now looking for 8 seconds with a SBC engine
http://www.youtube.com/watch?v=nVscbPHgue0&list=UUqIlXfSAoiZ--GyG4tfRrjw

https://www.youtube.com/watch?v=eg3avnsNKrc&index=2&list=FLqIlXfSAoiZ--GyG4tfRrjw
minorv8
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Post by minorv8 »

Well, the heads have been fitted regardless of whether they have been waste of time. I can always assemble a spare engine using the leftover bits knowing that it will perform quite well.

Perry, that was good news and may infact confirm what I suspected. If only the winter would come late this year... then I would have an opportunity to test the manifold before doing anything else to the engine.
minorv8
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Post by minorv8 »

Update, with Willpower manifold + 20 hp over Edelbrock, but the low end torque suffered as expected. I only swapped the manifold and ran it on rollers as is, no tuning whatsoever.
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Post by mgbloke »

Anyone want some.
http://cgi.ebay.co.uk/Rover-V8-Merlin-F ... 27adaf2f1f

Bit more expensive than real Steel.
mgbv8
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Post by mgbv8 »

I thought the Merlin things were Real Steels own heads??

I was happy to see a 25bhp increase with just a bigger carb and the Harcourt manifold on my standard (but home ported) 4.6 heads.
I made 395hp with gas on this setup.

I have modified my fuel and nitrous pipes now and I have proved the increased flow will give me another 60hp of gas and fuel on the original jets. If I add this to the extra 25hp nasp I reckon I will be in with a shot at making a flat 10 second pass next year.
Perry Stephenson
MGB GT + Rover V8
9.62 @ 137.37mph
Now looking for 8 seconds with a SBC engine
http://www.youtube.com/watch?v=nVscbPHgue0&list=UUqIlXfSAoiZ--GyG4tfRrjw

https://www.youtube.com/watch?v=eg3avnsNKrc&index=2&list=FLqIlXfSAoiZ--GyG4tfRrjw
chodjinn
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Post by chodjinn »

Whoa, Perry that's wicked!!!
mgbv8
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Post by mgbv8 »

Ollie!
I'm hoping to hit 450hp with gas on the stock engine next year!!
Thats my engine goal. My 1/4 mile goal is 10 seconds or better!!
Perry Stephenson
MGB GT + Rover V8
9.62 @ 137.37mph
Now looking for 8 seconds with a SBC engine
http://www.youtube.com/watch?v=nVscbPHgue0&list=UUqIlXfSAoiZ--GyG4tfRrjw

https://www.youtube.com/watch?v=eg3avnsNKrc&index=2&list=FLqIlXfSAoiZ--GyG4tfRrjw
CastleMGBV8
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Post by CastleMGBV8 »

So What are RPI charging an additional 50% for, over Real Steels price!!!!!

Kevin.
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Post by kiwicar »

"So What are RPI charging an additional 50% for, over Real Steels price!!!!! "
Because they are RPI and that is what they do :?
Mike
poppet valves rule!
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Post by katanaman »

What the hell is cast billet alloy? its either cast or its billet, good old RPI never fail with the bull :?
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Post by Coops »

wonder what RS would say about that advert :?
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