Brain Trust Needed - 2L Refresh Options

[yeahmag]

This might be long...

My current combo runs great, but I've been sitting on a set of Finch heads from Len Hoffman for years. There is no racing right now, so it seems like a good time. Here is the current combo:

2056cc
Stock Rods
Stock 2L heads (match ported)
86a Cam
9.5:1

I got a set of JE pistons in another deal (brand new, 96mm) and they appear to be stroker pistons. By my calculations I'd only need a 5.294" rod to counter the reduced pin height and am planning on a 5.325" rod or longer. Should be good either way there.

Now for the big problem. The Finch heads have a 50cc step-cut chamber. I like to run a tight deck (.04") and that combo would put me at 10:1. To get to the 9.5:1 I've been running I'd need to run almost .06" deck height.

So three questions.

1. Can the 86a handle 10:1 on 91 pump gas with proper tuning?
2. Is it better to run a loose deck and keep it at 9.5:1?
3. Put a 2cc (or larger) dish in the piston tops to keep a tight deck and lower the CR to 9.5:1 which I know works?

Thanks!

-Aaron

[Mblizzard]

Are you running carbs? Personally if you are going to be pushing the limits, a static tuned system is not the best. An aftermarket EFI can really help you fine tune your performance and it is easy to back out some timing for the non race days.

Couple of suggestions. Nothing wrong with stock rods but there are some much better options out there. Really wont make a performance difference but may help in longevity.

Next not sure of what ignition system you have you thought of 123 Ignition system. It is programmable and adjustable by bluetooth and cn adjust timing to account for the variation in octane levels. .

Consider adding octane booster for race days?

I have an excel file for calculating compression ratio and shim requirements that I can send if you PM me your email.