Jim,

If I could find them I would run the Champion surface gap plugs with a heat range of 10, which is really cold, but will reduce the chance of detonation. Plus they burn clean.

Jeff

Jeff ...... I found this spark plug chart . Is a C55VC or a C53VC the type of plug that you would recommend?

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Jim Villers
190SL, 230SL 5-speed, 95 E320 Wagon, 01 E320 Wagon, MGB, Boxster 'S', 190SL "Barn Find"

Hi Jim,

Yes those are the plugs. We found them to be as or better in most cases than anything else out there, even the $20 per plug NGK's.

I would buy the C57VC and C55VC first. I am sure one of these will fit the bill and provide the correct spark plug temps.

They will be several steps colder than your current plugs.

Jeff

Here I go again..... I installed colder plugs and headed off to the dyno shop again today to have everything checked out. On the street, the car felt very strong.

The dyno doesn't lie and is invaluable in evaluating what the engine is really doing. After a number of low speed runs to check fuel air ratios with and without boost, everything was looking good. Then as we began pushing it further, boost was a strong 6 psi and the engine began running lean at the higher RPM's. After trying several things, I monitored the duty cycle of the injectors and discovered the difficulty. The injector duty cycle was 100%. I needed greater injector capacity.

The installed injectors were Bosch 32 lb/hr; I have ordered a set of MSD 50 lb/hr injectors. They should be delivered on Tuesday and I will be back on the dyno on Wednesday.

The reason that we didn't find the problem the last time on the dyno was that the blower belt was slipping, resulting in less that 4 psi boos at 6000 RPM. Hopefully, this will resolve my piston burning condition.

The push is on to have everything set up correctly for the NASA track weekend at VIR.

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Jim Villers
190SL, 230SL 5-speed, 95 E320 Wagon, 01 E320 Wagon, MGB, Boxster 'S', 190SL "Barn Find"

Hey Jim:
Where can one get those MSD injectors? Do they bolt right up to a stock 16v? I am thinking of porting and polishing my head, so I don't want the engine to run lean if I do get the head worked on. Thanks.

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1985 190E 2.3-16 Euro

Kiato .... Finding injectors is easy...... but you need to convert to a digital engine management system and build a fuel rail to supply the fuel. I needed to do all of this to properly manage the supercharger that I installed. I am using an SDS engine management system.

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Jim Villers
190SL, 230SL 5-speed, 95 E320 Wagon, 01 E320 Wagon, MGB, Boxster 'S', 190SL "Barn Find"

Kiato,

I highly doubt that you will have injectors problems after doing some head work. The out put of your engine will not climb enough to outpace the the injectors. If your really worried you can increase the fuel pressure 5-10psi to increase injector flow.

Jeff

Jim, you were able to get the Champion plugs?

Jeff ..... No, I was not able to find a source of the Champion plugs. I did find out how to read the Bosch numbers and ordered a set of one and two steps colder plugs. I ran the one step colder during the dyno run; the developed a very light carbon look on the electrode.

I will be getting the larger injectors today and re-dynoing it tomorrow. I will try the colder plugs for my first track cycle and see what they look like. I am really thinking (and hoping) the injectors were the cause of my burnt pistons.

__________________
Jim Villers
190SL, 230SL 5-speed, 95 E320 Wagon, 01 E320 Wagon, MGB, Boxster 'S', 190SL "Barn Find"