Page 1 of 1

911R inlet manifolds

Posted: Thu Apr 29, 2021 9:09 am
by Madjad
Having received a COVID grant earlier in the year I’ve been investing in my product range.

Here is my first offering, a Pair of 96 mm tall 911R inlet manifolds
Recast in Aluminum to suit 40mm carbs
These were my machining trial, and identified an area on the pattern that needed to be adjusted, which has now been done.

On these ones I had to use a die grinder so two of the nuts and washers will fit.
They have been trial fitted and work with the std Weber linkage
£295

Also available to suit 46mm carbs

I am developing a variant to include efi or mfi injectors in the base of the manifold, along with 90 mm high Weber pattern high butterfly throttle bodies, which will eventually become a full efi kit in the near future

Re: 911R inlet manifolds

Posted: Thu Apr 29, 2021 11:05 am
by Madjad
Preview of the injector boss

Re: 911R inlet manifolds

Posted: Thu Apr 29, 2021 11:49 am
by MikeB
Hi what is the internal diameter at the cylinder head end, please?

Re: 911R inlet manifolds

Posted: Thu Apr 29, 2021 12:38 pm
by Madjad
MikeB wrote:Hi what is the internal diameter at the cylinder head end, please?
35mm as cast with 40 carb
39mm as cast with 46 carb

Obviously they can be bored, or left as cast so they can be matched to your head

Also forgot to say, I can also cast them in magnesium!

Re: 911R inlet manifolds

Posted: Thu Apr 29, 2021 8:29 pm
by PhilipB
Apart from looking good what do these manifolds do to engine performance? Do they only work with certain types of cam?


Sent from my iPhone using Tapatalk

Re: 911R inlet manifolds

Posted: Thu Apr 29, 2021 9:37 pm
by Lightweight_911
.

Engines with more 'aggressive' cams - like the 911R/906 - which have lots of overlap, can suffer from fuel reversion at low to med revs where pulses up the intake hit a certain resonance & create a cloud of droplets floating above the mouth of the carb.

The 911R/906 manifolds at 98mm tall compared to the std 2.0 Weber manifolds which were 68mm had the effect of altering the frequency of the pulses meaning that they no longer matched that resonance & the cloud of droplets disappeared ...

.

Re: 911R inlet manifolds

Posted: Thu Apr 29, 2021 10:56 pm
by Lightweight_911
.
Basically the end result was improved torque/drivability at low/medium revs ...

.

Re: 911R inlet manifolds

Posted: Fri Apr 30, 2021 10:19 am
by Madjad
Lightweight_911 wrote:.

Engines with more 'aggressive' cams - like the 911R/906 - which have lots of overlap, can suffer from fuel reversion at low to med revs where pulses up the intake hit a certain resonance & create a cloud of droplets floating above the mouth of the carb.

The 911R/906 manifolds at 98mm tall compared to the std 2.0 Weber manifolds which were 68mm had the effect of altering the frequency of the pulses meaning that they no longer matched that resonance & the cloud of droplets disappeared ...

.
The production manifolds will be 98mm tall

Re: 911R inlet manifolds

Posted: Sun May 02, 2021 8:23 am
by Madjad
Working on fitting the injectors