Merlin Heads

Speed 8 · Post by **Speed 8** » Tue Aug 11, 2009 6:35 am

mgbloke wrote:Minorv8
...
l Steel today and was told that sadly John had been taken ill and passed away Thursday night. As a result RS was closed Friday.
...

Very very sad news.

RIP, best wishes go to his family and friends...

CastleMGBV8 · Post by **CastleMGBV8** » Tue Aug 11, 2009 9:13 am

I have sent a personal e-mail today to Charles at Real Steel passing on our sympathies.

Kevin.

minorv8 · Post by **minorv8** » Thu Aug 27, 2009 4:32 pm

I got my pair of heads yesterday and they do look nice. To really see what they are worth I have booked a dyno session for next Thursday to get a base line figures. After that I will swap the heads and book another session. I´ll keep you posted if someone is interested.

Darkspeed · Post by **Darkspeed** » Thu Aug 27, 2009 6:16 pm

Well here's one on person who would be very interested in your findings.

Andrew

ged · Post by **ged** » Thu Aug 27, 2009 6:52 pm

And here's another.

kokkolanpoika · Post by **kokkolanpoika** » Sat Sep 26, 2009 12:32 pm

So.. any dynosheets?

It has been a long time when you boys receive those heads.. So there must be some data to available for those heads vs ported rover heads..

Because i dont belive merlin´s flow capacity..

badger · Post by **badger** » Sat Oct 03, 2009 3:29 pm

Any news for us yet minorv8?
I've a pair on the shelf that I bought from a forum member some time back - what I build to fit them to depends a great deal on your findings.....

minorv8 · Post by **minorv8** » Sun Oct 04, 2009 10:13 am

Sorry, had written the results in the single plane manifold thread. Here they are again:

Merlins were worth 11 hp compared to the previous head. As I feared the power drops quite fast after peaking at 5600 rpm, about 15-20 hp and then levels again. Richening the sec side jetting produced an identical curve, only 10 hp lower on the graph. No matter the trick, the max power was always around 5550 rpm and tailed off past 5600 rpm. So, looks like Performer is indeed at its maximum. Next phase will be another manifold. Best curve was with 65x52 needles, 86 primaries and 95 secondaries i.e. 1404 std spec, 13 deg basic and 30 deg total timing. Most likely more torque is available below 2500-3000 rpm with more advance but there was no point in experimenting given the situation at top end. With my old heads the jetting was 68x57, 86 primaries and 92 secondaries. The CR is down to 9,8:1 with the Merlins compared to the previous 10,4:1.

I have spoken with Charles at Real Steel and he was also surprised at the change. I have also bought a single plane manifold, don´t know when it arrives. Hopefully before the snow comes so I just might be able to visit the rollers again before the car is put back to garage for winter. My manifolds are with 1,5" primaries so mayber there is also something to be gained.

crayefish · Post by **crayefish** » Mon Oct 05, 2009 8:39 am

minorv8 wrote:Sorry, had written the results in the single plane manifold thread. Here they are again:

Merlins were worth 11 hp compared to the previous head. As I feared the power drops quite fast after peaking at 5600 rpm, about 15-20 hp and then levels again. Richening the sec side jetting produced an identical curve, only 10 hp lower on the graph. No matter the trick, the max power was always around 5550 rpm and tailed off past 5600 rpm. So, looks like Performer is indeed at its maximum. Next phase will be another manifold. Best curve was with 65x52 needles, 86 primaries and 95 secondaries i.e. 1404 std spec, 13 deg basic and 30 deg total timing. Most likely more torque is available below 2500-3000 rpm with more advance but there was no point in experimenting given the situation at top end. With my old heads the jetting was 68x57, 86 primaries and 92 secondaries. The CR is down to 9,8:1 with the Merlins compared to the previous 10,4:1.

I have spoken with Charles at Real Steel and he was also surprised at the change. I have also bought a single plane manifold, don´t know when it arrives. Hopefully before the snow comes so I just might be able to visit the rollers again before the car is put back to garage for winter. My manifolds are with 1,5" primaries so mayber there is also something to be gained.

11hp extra (at a lower rpm point than it should be due to the dual plane manifold) with a .6 drop in compression ratio is pretty good.

with a raise in comp ratio and single plane manifold it looks like you might get a nice little boost of peak power

someday someone should do a true like to like comparison (ie. both single plane and both the same comp ratio...)

kokkolanpoika · Post by **kokkolanpoika** » Tue Oct 06, 2009 3:25 am

I always say that those heads are waste of money..

I think i can cuarantee that rover stage 4 heads will flow better than merlins..
If those heads are better than std rovers, why there is no more dyno sheets on this forum?
I estimate that real steel is selling approx 10pair of those heads in bast ½ year?
So are all those heads in their owners garage´s table..?

I have seen RPI:s 307hp dyno sheet on youtube.. But that dosen say anythink, because you can get almoust same figures at stage 3 heads..
And 337hp real steel figures at 5.0 engine dosen soudn any good to me... the cam is quiute agressive etc..

So we want more dyno sheet with those heads..

JP. · Post by **JP.** » Thu Oct 08, 2009 5:42 pm

kokkolanpoika wrote: If those heads are better than std rovers, why there is no more dyno sheets on this forum?

So we want more dyno sheet with those heads..

Cause those guys running them turned away from this forum.

I had more than 10bhp increasement when switching over to Merlin heads.

But hey I won't even bother to scan my sheet and post it here.

Eliot · Post by **Eliot** » Thu Oct 08, 2009 6:34 pm

JP. wrote:
kokkolanpoika wrote: If those heads are better than std rovers, why there is no more dyno sheets on this forum?

So we want more dyno sheet with those heads..
Cause those guys running them turned away from this forum.

I had more than 10bhp increasement when switching over to Merlin heads.

But hey I won't even bother to scan my sheet and post it here.

10Bhp isn't much of a gain is it though.

kokkolanpoika · Post by **kokkolanpoika** » Fri Oct 09, 2009 6:04 pm

JP. wrote:
kokkolanpoika wrote: If those heads are better than std rovers, why there is no more dyno sheets on this forum?

So we want more dyno sheet with those heads..
Cause those guys running them turned away from this forum.

I had more than 10bhp increasement when switching over to Merlin heads.

But hey I won't even bother to scan my sheet and post it here.

You don´t bother to scan your dyno sheet on this forum? Why? Is it disappointment vs stage 3 rover heads??

Post by **Coops** » Fri Oct 09, 2009 7:21 pm

what bothers me is why did they turn away from the forum?
and where did they go

mgbv8 · Post by **mgbv8** » Fri Oct 09, 2009 7:22 pm

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.