19 replies to this topic

[nikollou]

Hi all thanks again for the support. 

 

Ok so to get back to a couple issues raised:

 

 

I'm still confused by 9 & 10. Unless you're planning on physically removing the turbo there's nothing to be gained and potential to damage the turbo if it's still hot or just windmills. If you want a switch, use it to limit the boost with a solenoid bleed off valve  - much like the Turbo Metro did. 

Yes I'm planning on physically removing the turbo when I have to participate in historic racing events as the car would not qualify. The switch refers to the programmable distributor's map selection switch which I will use to toggle between N/A and turbo maps.

 

 

 

Are you restricted with what you can do to the head by regulations or budget ?

What are you thinking of exactly? The historic racing will require the engine bay to look at least to the better part original. So the 12G940 head I have can be modified as much as I want on the inside & I can also play around with the rocker if deemed beneficial.

 

 

Since 10 psi would warrant an intercooler and I definitely do not want to go down that path for simplicity of swapping and to keep the install at least partially original (i.e. in the spirit of the metro turbo or ERA setups), what would be a max safe boost level to run without intercooler? I have been doing some searching around here and other sites and it seems I might go for essentially the Metro Turbo setup of approximately 7-7.5psi and 9.5:1 comp ratio. Any strong objections to this? Any idea what HP levels I'd get? Since the Metro got just shy of 100BHP would I get something better than that with the ported head and uprated cam?

 

Updated build specs:

• GT15 turbo @7psi boost hoping for ?BHP
• 1275cc +0.30 dished pistons
• 12G940 head with stage 1 porting
• 9.5:1 compression ratio
• Swiftune SW507-or-equivalent cam

 

Here is the updated swap to-do list:

1. Disconnect & remove existing carb/intake/exhaust manifold (LCB)
2. Install turbo exhaust manifold (mirage type - no turbo box installed so possibly tilt engine slightly forward with adjustable top poly bar)
3. Install turbo (GT15)
4. Connect turbo to exhausts system (custom piping down to remaining Maniflow system minus the LCB)
5. Install Turbo set-up Carb
6. Connect Turbo to Carb via MG Metro plenum (with incorporated DV) and silicone hose (no intercooler)
7. Hook up carb to control cables & fuel feed
8. Hook up turbo to oil system & water system
9. FLICK TURBO SWITCH ON DASHBOARD
10. Start engine and smile   

[Turbo Phil]

What exactly do you mean by stage 1 porting ? If you're looking to get the most output at a low boost level you'll need to do some proper head work.
If you can't run an intercooler, what about water water/meth injection ? This would allow higher boost to be used.

Phil.

[nikollou]

Hi Phil I have bought David Vizards Tuning the A Series Engine and when I say stage 1 I mean I will be performing mainly the modifications covered in the "Cylinder Heads Part 1" chapter. That would involve blending in the short side radius, reforming the valve guide boss and performing some basic opening of the intake-exhaust ports. I will also be using rim-flo style hi flow valves and will work on the combustion chamber area to enhance flow as per DV's diagram but then skim down the head to get the right CR obviously.

 

Does that sound about right? Or would that not be enough?

 

As far as water injecting the engine I had never heard of that before but I will have a read as it might be an option for me.

 

Sorry to bring these up but I wanted to verify a couple choices:

1) Am I correct in choosing the GT15 turbo vs the T3 for this build?

2) Do you agree with the SW5-07 cam choice?

 

 

I also thought I'd post a couple pictures as I have been doing a lot of talking and possibly got people bored, so here's some of my progress:

 

I'm currently still working on the body where have been painstakingly removing all 8 layers of paint and primer that were on the car since 1975 section-by-section then making any necessary amends/repairs to the metal, grinding, applying phosphoric acid, hand sanding and finally applying the base layer of epoxy primer by air gun. Hopefully by getting rid of all the paint and rust and properly sealing all the healthy metal under a bunch of epoxy primer I'll have a -relatively- rust proof mini..!!

 

(OK been trying to embed a few photos using imgur -after following this thread with no luck so far. Will keep trying because for some reason I keep getting an error "You are not allowed to use that image extension on this community.". The images are straight off my iphone in jpg format can't imagine that is an unsupported format...?)

 

https://www.dropbox....4c/IMG_5919.JPG

https://www.dropbox....tf/IMG_5920.JPG

https://www.dropbox....tl/IMG_5946.JPG

Edited by nikollou, 23 November 2017 - 10:54 PM.

[r3k1355]

Yes if you can't run an intercooler then water/meth injection is a very good idea.

 

Devilsown sell a decent kit.

[nikollou]

Hello everyone,

 

I'm nearing the completion of the bodywork on my project so I will be tackling the engine very soon.

 

As an update I am currently working with these parts/specs:

SW5-07 cam and will be keeping the 1.3 ratio rockers for now. Cyl head is a 12G940 with 35,6 and 29,2 valves. I have bought an Aluminium radiator, T25 compatible exhaust manifold and metro turbo plenum. I have a 123+ distributor which has a switch to swap between two maps. Piston and valves are the race quality minispares products. Finally I have purchased a cross-pin diff, but plan to keep the helical gears in the box. 

 

It was mentioned that it would be easy to have a switchable setup of say a 7psi and a 15 psi boost so after all the research and advice I have received I am looking at having the following three "modes" for my car:

 

1) N/A mode: All turbo parts removed, I will have a map on the dist that will be tuned to local gas quality and N/A use. I am slightly concerned that at 9:1 comp ratio it will feel a bit sluggish but I can't have it all. Cyl head flow will be important here.

 

2) Turbo low boost: Turbo parts installed. 7-8psi boost and no intercooler - basically a Turbo Metro setup. Dist map will be switched from the N/A to one set up for this use. 

 

3) Turbo high boost: Water/meth injection and boost up to the max level I will get via trial and error.

 

MIni13 mentioned in post #3 that a switchable boost setup is possible. What is involved in creating one? 

 

I also have another question, I am planning on adding an oil cooler w/ thermostat and an oil temp gauge in the cabin, to have a better handle of engine temps and avoid any unpleasant problems in the future. Where should I tap the block for the oil temp sensor? I did some research but couldn't find a definitive answer.

 

Last but not least, I will be taking the block and head to the machine shop next week, any last comments on the target compression ratio of 9:1?

 

Thanks,

Nik