Pulse Jet Ignition - Claimed 10% increase in power - first impressions

[Simon_London]

https://tinyurl.com/yb6qwuux

Well my original post generated quite a bit of controversy.

I contacted Steve Scriminger who makes them in the UK and he gave me a set.

So what are they like?

Suffice to say that are staying on the bike.

They may well increase power somewhat but that's not the main event.

The bike feels different and sounds different.

Its smoother, more tractable, revs a bit quicker. the slight flat spot on Guzzis at 3-4000 revs is less noticeable, it seems to need a bit less throttle for a given engine speed. The improved smoothness is really noticeable. I have an 1100 Sport flywheel on my bike so it felt a bit lumpy at lower revs. It feels much smoother now.

I only had to make a small adjustment to idle screws. Plugs nice brown colour. Bike thrashed up to 120mph and quite happy.

Love this mod.

Bargain.

If you decide to get a set please mention my name

[lazlokovacs]

nice one!

[fotoguzzi]

I'm still skeptical.

[Simon_London]

The first set of plugs that Steve sent me were resistor plugs (NGK CR8HSA) and didn't work well. Steve sent me some non resistor plugs (C8HSA) instead and they were great. The high compression Le Mans engine run resistor plugs as standard but low compression engines - T3 G5 SP run non resistor plugs.

[Simon_London]

Here is some info from BMW users.

https://www.motorworks.co.uk/vlive/Shop/Parts.php?T=6&Q=ELA01261

https://tinyurl.com/y93xasmv

[twowings]

Well, at least that's what the butt-dyno says...enjoy your gizmo!

[Simon_London]

So my final word on Pulse Jet Ignition.

Does it work? I think yes, but I have gone back to the standard plugs. Why?

The bike was already sweet and tractable from 2000 revs to red line. Should be  - new nikasil 950 barrels and pistons, reconditioned heads, ported for 36mm carbs, HMB Cam and jetting............ .

The bike is just too precious to me to use unproven technology. It is already quick but relaxed and reliable. Time to just enjoy it.

So I bought a 2000 Ducati 900SS to mess about with instead!

[Tom]

 

[danomar]

This is similar to the idea behind Honda's CVCC engine in the 1970s-80s. A small stratified charge ignited the rest of the mixture resulting in all sorts of niceness. Unfortunately, the Pulse Jet is reliant on the engine's original setup, but in theory is could work well. In theory, that is. How it applies to specific combustion chamber/valve profile/carburetion designs remains a big variable.

[LowRyter]

I am bit confused since you were initially happy with the performance and said the plugs looked good.  I don't see a risk or downside.

[Simon_London]

I do think these things work.

To me the bike feels a bit leaner burning and I think is running hotter using the Pulse Jet plugs.

Whilst I have been impressed with the effect, I feel a bit nervous about the long term effect on engine health. Why take the risk?

[Tom]

IMHO running an air cooled engine lean (edited) is not the best option.  If it works for your bike and the option was free........(Guzzi content"   

[LowRyter]

Yeah,  don't want an air cooled bike running hot.  Especially in traffic. 

[Tom]

Yeah,  don't want an air cooled bike running hot.  Especially in traffic.

eh......not hot.