Engine Choice

[Excaliber]

My side oiler was not very 'streetable' when I bought my ERA. Heres what that meant to me. The compression ratio was to high, I had to run the timing retarded and use the highest octane I could find or it would 'ping' without mercy. The cam profile was SO radical I had to keep the engine rpms around 2800 to 3000, which meant constantly watching the tach and selecting the appropriate gear. It had terrible 'bottom end', the motor would 'spit' through the carbs and tend to stall unless you kept it reved up and slipped the clutch to get underway. And NEVER, NEVER, lug it, ALWAYS select a lower gear if your gonna put your foot in it.

But man was it at home on the track!! DAM that car was fast! The 660 center squirter carbs loved wide open throttle, and little else. There was no 'in between', go or stop, that was about it.

So I rebuilt it. Lowered the compression, milder cam, smaller vacuum secondary carbs but I STILL retained the fairly radical high riser heads. Those heads are not generally recommended for good 'street manners', but a lot of that depends on many other factors as to how 'streetable' it is. I have high gear ratios, lower would perhaps be better. But with the milder (and STILL fairly wild) cam and carbs and lower compression, yeah, it's not bad. I'm comfortable on the 'street', and it STILL runs in the 11's at the race track!!!

So I would say to those that say a motor isn't 'that streetable' it depends on other factors as well, how YOU like to drive and the carbs can make a BIG difference.

One thing to REALLY watch out for, no matter which engine you choose is the compression ratio. You want it to be able to run on 'pump gas', using "Octane Booster" and looking for 'Race Gas' gets old in a hurry and it's NO FUN!

[STL Mark]

Excellent advise Xcalibur!

I have tell everyone - in between posts - I decided to tell my wife about my confusion re: SB vs. BB. I thought that she would have no idea - and just say whatever. Boy was I wrong. I'm sure you guys are all aware that sometimes "THE Cobra" can be a touchy subject around the house. I was pretty sure she was getting sick of me talking about it every day - UNTIL tonight!

So - I tell her the specifics about my engine confusion (just like my original post) - she listened quietly - then tells me that she would regularly race guys when she was a kid (1980's). She had an old Trans Am (big block) that had significant work - she said those small bock guys would always beat her off the line - but she would always blow their doors off by the end of the race. (She had a Shelby Mustang when she was 16 too!)

She said - "Go for the big block - they sound better anyway - like a Harley - and when you're just cruisin around town - isn't the sound - just as important as anything else?" She continued - get it built right - get it the way you want. You guys on this forum are way cool - but Damn she's awesome. Married 20 years - never knew she was a RACER!
http://www.clubcobra.com/forums/imag...s/laughing.gif

Mark

[Stentor]

Mark,

Based on your conversation with your wife, it sounds like you might be headed down the big-block path. I've only heard good things about the 460 big-block motors. In fact, when I was headed down the SPF path I was going to build a 514 ci engine for it (slightly smaller version of the 557).

With a 557, you'll need to make sure that the correct manifold is used to allow adequate clearance for the hood in the SPF (I am sure this is top of mind for Eric, given the number of Cobras he's finished). Also, you might want to consider modifying the stock SPF sidepipes to let that big engine breathe better (as you can lose considerable HP due to the stock sidepipes with a motor like that; Eric can also address the sidepipes for you). However, if you modify the sidepipes, the car can be substantially louder. Again, it's all about your preferences.

I agree completely with what the other guys said about compression ratio and pump gas (too high of a compression ratio = won't run on pump gas). It can be a real pain if your engine doesn't run on high-test pump gas.

Best regards,

Kevin

Originally Posted by STL Mark

Excellent advise Xcalibur!

I have tell everyone - in between posts - I decided to tell my wife about my confusion re: SB vs. BB. I thought that she would have no idea - and just say whatever. Boy was I wrong. I'm sure you guys are all aware that sometimes "THE Cobra" can be a touchy subject around the house. I was pretty sure she was getting sick of me talking about it every day - UNTIL tonight!

So - I tell her the specifics about my engine confusion (just like my original post) - she listened quietly - then tells me that she would regularly race guys when she was a kid (1980's). She had an old Trans Am (big block) that had significant work - she said those small bock guys would always beat her off the line - but she would always blow their doors off by the end of the race. (She had a Shelby Mustang when she was 16 too!)

She said - "Go for the big block - they sound better anyway - like a Harley - and when you're just cruisin around town - isn't the sound - just as important as anything else?" She continued - get it built right - get it the way you want. You guys on this forum are way cool - but Damn she's awesome. Married 20 years - never knew she was a RACER!
http://www.clubcobra.com/forums/imag...s/laughing.gif

Mark