Porting a Spree

OSUEngineGuy · Post by **OSUEngineGuy** » Mon Aug 04, 2008 2:01 am

I have been lurking around the forums for a while. I bought a pair of disassembled sprees for $400. I am looking to make some performance mods to one of them and need some advise. I want to keep with the spree engine, looking for this to be more of a fun project. I have access to a full shop including cnc.

My question is about porting though. I have been reading the jennings articles and will be following them for my exhaust and exhaust port, but what about the transfer ports? Since there are three on the spree, how do you follow the basic rules that he gives? Also has anyone ported the intake in the case of the spree?

One that I am really interested in is the reed valve. I know that the sb50 reed valve will fit on the spree, but has anyone tried to port the spree reed valve? Are there any known problems from it? Seems to me like you could match it to an intake a lot better that way.

Thanks for any help in advance!

Kenny_McCormic · Post by **Kenny_McCormic** » Mon Aug 04, 2008 2:06 am

I have ported the spree intake manifold (great bottom end gain) but thats all so far.

Post by **noiseguy** » Mon Aug 04, 2008 10:24 am

I don't see how you could port the stock Spree reed block. The reeds barely cover the the reed block in the unmodified state. By the time you run down a set of different (larger) reeds, you'll be time and money ahead to just buy the larger SB50 set.

It's a size issue, not a matching issue. The SB50 intake is much larger than the Spree intake; larger than you could ever port the stock Spree manifold to.

OSUEngineGuy · Post by **OSUEngineGuy** » Mon Aug 04, 2008 11:41 am

ahhh, I see.

I think I'm going to do a little experiment!

Does anyone have an SB50 reed valve and inlet pipe that I could buy from them?