7 replies to this topic

[ax7]

Hi all, this is my first post - I searched, but hoping for a little advice specific to my setup.

 

For the last 5 years I have been the very happy owner of an Aus Morris MK1 850 with a Minimania built 1380 supercharged engine, amongst various other performance mods. The engine currently has / is:

• 1380cc
• Autorotor pull through supercharger, 7psi
• 8.5:1 CR (from Minimania info on engine build)
• HIF44 carb
• 731 cam
• Alloy head (C-AHT345)

• Dual valve springs

• A+ sintered rockers

• LCB 1.75" manifold, jet hot coated

• 2" single box exhaust

• Aldon yellow, Pertronix Ignitor II & Flamethrower II

Other than starting difficulties in cold, the thing hauls and I love it. Curious about improving performance, with best bang for buck and without chasing my tail on diminishing returns. Happy for advice or any other feedback outside of what I might be looking at.

 

Question, are 1.5 roller rockers worth it on this setup? And any recommendation on Minispares, Minisport or MED? Would anything else be require after installation, just a retune?

 

Many thanks

[nicklouse]

Would not bother. You will lose low end torque, gain very little In real world BHP and wear the valve train out faster.

[dyshipfakta]

Smaller pulleys on the blower higher boost but runs the risk of detonation. To be honest I think that setup is about optimum with out changing things significantly ie blow through with intercooler etc.

[ax7]

Thanks for the prompt replies - sounds like money better spent on the rolling road.

 

I considered a smaller pulley, and we have good access to 98RON in Australia, but 7psi gives me the safety to nurse it home if I ever had to fill up on 96RON.

 

As a side question, cold (< 10C/50F) starting is a REAL chore; lots of cranking, weakly catches, massaging wide open throttle for about 30 seconds to get the revs to slowly build up. I've always set my advance to 24deg based on the literature I received with the car - does that sound right or this my source of trouble?

Edited by ax7, 24 June 2020 - 11:39 PM.

[dyshipfakta]

I think it’s just a quirk of the system with the hiff supercharger setup to be abit of a pig to start. Takes ages to get sufficient fuel to where it needs to be. Warm starts are easier because some of the fuel sits on the supercharger blades. No personal experience with this just what I have read from my research.

[Curley]

Have you considered going to crank fired timing or EFI? Wont add mega power but adding idle control functions should help with your cold start issues.

 

What about E85?

[ax7]

Hey Curley, cost and 'is it worth it' are the prohibiting thoughts on going down that road. So far it has always started, just a lot of cranking and nerves. I don't think I've ever had to start sub zero, which plays on my mind if I did a winter overnight country road trip and parked it outside. The knowledge that it is 'normal' as dyshipfakta mentioned with my set up helps ease the stress. I put in a high torque inertia starter that doesn't kick out a few months back and that has helped while also putting less strain on the battery.

 

I would have change all the rubber lines and retune carb for E85 no? Then the benefit is really seen if I increase boost and compression? E85 is less readily available in Aus than 98RON, and retuning to E85 would get rid of that flexibility to run on 98 or 96 I assume...

[dyshipfakta]

I think the logic is that you have to get fuel from the carb all the way up the inlet pipe then through the charger before it will even splutter.