Page 2 of 2

Posted: Mon Sep 14, 2009 7:51 pm
by HairbearTE
crayefish wrote:
minorv8 wrote:I have currently the Performer manifold but I am slightly sceptical whether it has enough flow capacity past 5500 rpm. Edelbrock designed it for 3,5 litre engine with idle to 5500 range. I am running a 4,6 litre engine and shift at 6300 rpm at 1/4 mile. The peak hp at rollers is at 5600 rpm.

Now that I have the Merlins fitted the issue is more than interesting...
Do they make the Performer RPM for the Rover? That would shift up the power band of the manifold by about 1000. It seems to be a very popular manifold for the sbc. Also the airgap ones too as they run a bit cooler.

Perhaps its possible to 'convert' a Performer to a Performer RPM.... as far as I can tell from photos, the main difference is that there is a hole in the divider between the two halfs.... hard to explain but you can see in these photos.

http://www.summitracing.com/parts/EDL-7 ... mage=large

http://www.summitracing.com/parts/EDL-2101/?image=large

Kinda makes it a cross between a single and dual plane.... However the same could be achieved with an open spacer (which is cheap!).... try that first perhaps?
They don't yet make a performer rpm, or the air gap version for the RV8. It's a shame really because as you say the rpm is very popular for use with the small block chevy and is as you said worth 1000 rpm. I believe the RPM is taller than the standard performer. The jury is certainly still out on the air gap! back-to-back tests vs the rpm in some U.S mags showed such a marginal difference in performance as to be negligable. The idea makes sense but unless you can get a good deal of cool air flowing under it I think it makes no difference. The standard performer for the RV8 is a great manifold for the engine but undoubtly restricts the power peak to 5500 rpm or so.

Posted: Tue Sep 15, 2009 6:39 pm
by CastleMGBV8
Minor,

If you wanted to experiment you could convert the Performer to unheated and fit a thick spacer as I suggested earlier

You would have to cut off the two front sections where the water ports from the head mate with the performer and then use a seperate bridge piece with a thermostat housing, JE Developments I believe have these for approx £50.00

Yoy may need to rig up a a by pass so you have circulation prior to the stat opening.

It would also be helpful to port the manifold to match the ports in the Merlin heads.

Other than that it's stump up the dosh for the Wilwood/Wildcat inlet manifold.

Kevin.

Posted: Tue Sep 15, 2009 7:33 pm
by CastleMGBV8
For those who like the tech stuff, Flow data for the Wilwood inlet from Dan Jones. on the British V8 Forum.

Kevin.

Re: rover 3.5 single plane intake??

Posted by: Dan Jones
Date: September 14, 2009 06:04PM


> Of the three manifolds, Wildcat, Harcourt or Willpower I don't think
> there is a lot of difference as they are all based on the original
> Huffaker as far as I can find out.

I don't believe that is the case. I have both a Willpower and a
Huffaker here. They are different intakes and performed differently
in my flow bench testing. The Huffaker has Buick 300 sized ports
and requires an external thermostat. The Willpower has ports
slightly larger than a Rover/Buick 215 and has an integral thermostat.
The Willpower can also be ordered with injector bungs. The Willpower
is apparently the same as the Wildcat intake, though.

Here's a previous post I made after testing the Huffaker and Willpower
intakes:

After the heads were ported, I spent a little time evaluating a couple of
Rover V8 single plane intake manifolds on Dave McLain's flow bench in Cuba,
Missouri. I wanted to know which of the intakes would flow best when bolted
to the ported 1964 Buick 300 aluminum heads. The two intakes tested were a
Huffaker:

[www.bacomatic.org]
[www.bacomatic.org]
[www.bacomatic.org]

and a Willpower:

[www.bacomatic.org]
[www.bacomatic.org]

Note the Willpower intake pictured is not the actual intake tested. I've
not yet taken pitures of the intake we tested but it differs from the one
pictured in that it has EFI injectors bungs in each port but the injectors
were not installed for these tests. The Huffaker has larger ports which
better match the Buick 300 heads:

[www.bacomatic.org]

The Willpower has smaller Rover-sized ports but has a better radius on
the end runners than the Huffaker. An end port and a center port of the
head were first flowed without an intake attached to get a baseline, then
flowed with the intake bolted in place. Also, a Holley 780 carb body
with the throttle plates at full open was bolted to the intake to
represent the pressure drop across a carb or fuel injection throttle body.
I'll be using an EFI throttle body later but have not purchased it yet.
When the heads were ported, they were tested on a Superflow bench at a
28" H2O pressure drop. The head had a clayed intake radius but no exhaust
pipe stub was used on the exhaust. Those numbers are shown in the 2nd and
3rd columns. The 4th and 5th columns are the same head flowed on Dave's
bench which has a 10" H2O pressure drop. The numbers were converted
mathematically to 28" to be on a consistent basis. Note the numbers are
somewhat lower than those of the 28" bench. We're not sure if this due
in part to the conversion or is simply bench-to-bench variation. In any
case, it doesn't influence the results of the intake manifold tests.
On both single plane intakes, the center runners are short and straight
while the end runners are long and curved, so one center port and one end
port were tested. The Huffaker was bolted to the head and tested first,
followed by the Willpower. The results are shown below and are best
viewed in a non-proportional font like courier:

Valve Buick 300 Ported Buick 300 Same head with Same head with
Lift 1964 head on McLain's Huffaker intake Willpower intake
(inch) aluminum flow bench center runner center runner
ported 10" numbers
Int Exh converted to 28" CFM % of CFM % of
1.775" 1.5" Int Exh bare bare
1.775" 1.5" head head
Int Exh
center
port

0.050 -- -- 26.3 22.6 26.1 99.2 27.6 104.9
0.100 66 47 56.3 51.6 55.1 97.9 56.4 100.2
0.150 99 82 86.8 75.0 87.8 101.1 89.0 102.5
0.200 129 104 115.1 98.4 117.2 101.8 119.1 103.5
0.250 155 119 140.4 114.1 141.4 100.7 142.8 101.7
0.300 174 130 158.1 125.4 160.6 101.5 160.0 101.2
0.350 187 139 171.7 134.4 169.9 98.9 167.9 98.0
0.400 191 146 179.8 140.2 170.5 94.8 172.2 95.8
0.450 194 150 181.3 143.2 172.6 95.2 174.3 96.1
0.500 196 152 182.1 144.3 173.9 95.5 175.3 96.2

Valve Buick 300 Ported Buick 300 Same head with Same head with
Lift 1964 head on McLain's Huffaker intake Willpower intake
(inch) aluminum flow bench end runner end runner
ported 10" numbers
Int Exh converted to 28" CFM % of CFM % of
1.775" 1.5" 1.775" 1.5" bare bare
end head head
port

0.050 -- -- 25.5 22.6 26.8 105.9 26.9 105.5
0.100 66 47 55.0 51.6 56.6 102.9 55.4 100.7
0.150 99 82 87.0 75.0 88.2 101.4 88.6 101.8
0.200 129 104 116.9 98.4 114.1 97.6 119.8 102.5
0.250 155 119 143.4 114.1 132.5 92.4 144.6 100.8
0.300 174 130 157.8 125.4 146.5 92.8 164.8 104.4
0.350 187 139 171.6 134.4 155.6 90.7 173.3 101.0
0.400 191 146 178.3 140.2 156.9 88.0 175.0 98.1
0.450 194 150 180.8 143.2 156.6 86.6 176.0 97.3
0.500 196 152 182.9 144.3 157.6 86.2 175.3 95.8

Despite the smaller runners, the Willpower is the better flowing manifold.
The center ports on both intakes are quite close to the head flow but
the Huffaker end ports are not as good. I think it would be worthwhile to
port just the ends of the Huffaker intake end runners with a better radius
to see if the flow loss could be recovered. There's a slight drop off in
flow as lift increases on the Willpower intake that may be due to the small
port size. The Willpower could be ported to a larger size but given how
close the intake is to the bare head flow, it's probably not worth the
trouble. The worst flows are at 96%. As a point of comparison, we've
recently flow tested a couple of (non-Rover) dual plane intake manifolds
and they were in the mid seventy % flow range (unported).

The exhaust-to-intake flow ratio on these heads is excellent. Dave thought
a bit larger itake valve, at the expense of exhaust valve size, might make
more power if it were practical. During our tests, a 4" diameter tube was
used to simulate the effects of the cylinder wall. To see if shrouding
might be a problem, the tube was moved around (closer to the valve) but
little effect was noted.

Dan Jones

Posted: Wed Sep 16, 2009 6:17 am
by minorv8
I am doing some "research" for the fun of it. I had the car on rollers with the former spec, and have now fitted the Merlins and driven the car. I´ll take it back to rollers to see how much the heads (hopefully) made difference. I have kept everything else the same. Obviously the CR is somewhat lower than before.

Like I stated earlier, I have already ported the manifold and have fitted a 1 inch spacer. I also run a stub stack with the carb. I don´t want to cut the Performer up since I have plenty of surplus stuff for another engines. Besides, modifying the manifold to unheated version does not fix the possible flow limitations due to design.

Next step will be either the manifold or another cam. I am not sure whether to go to EFI (I have Efi manifolds and Haltech ECU) or maybe try the single plane manifold.

Or, since I have a AC TIG welder, maybe a fabricated manifold would be an option. We do have long winters in Scandinavia...

Posted: Wed Sep 16, 2009 9:43 am
by CastleMGBV8
Minor,

Did not know you were in Scandinavia, in other warmer locations running an unheated manifold does have an effect as it provides a cooler and therefore more dense charge to enter the engine and this will make more power.

You say lower compression, what size are the chambers in the Merlin heads as they look smaller in the pictures?

If you have an EFI system and a Haltech it sounds like a good alternative especially if you port the manifod and trumpet base with bigger trumpets and possibly have the throttle body bored out for a larger 72mm throttle.


Kevin.

Posted: Wed Sep 16, 2009 10:01 am
by minorv8
Cold climate is really not a problem, the car is definitely not a winter car. Yes it´s practical to keep the manifold as cool as possible (one reason for Air Gap manifold design) provided icing is not a problem.

The chambers in Merlins were about 33 cc, whereas the previous heads were 29 cc (4,6 variants). So, with my spec the CR is down from 10,4:1 to 9,8:1.

The EFi manifold is already ported and the ports at trumpet base face are 43 mm in diameter. The trumpet base is bored out to 46 mm and will have trumpets with 43 mm ID and 46 mm OD. I have also modified the plenum to twin plenum variant. The exact size of throttle bodies is not decided yet since they will be bolt on items.

Posted: Sat Sep 26, 2009 5:29 am
by minorv8
Merlins were worth 11 hp compared to the previous head. As I feared the power drops quite fast after 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.

BTW, as already commented the RPM version is higher, about 1 inch for SBC.