BB512i performance upgrades?

I recently bought a set of 365BB cams for my injected car and started a thread on it. The profile difference is large, plenty to be gained with cams. The headers suck, especially around the axle shaft area so a set of tubi headers or custom ones would also provide a gain. I plan to retain the CIS for that original look as well after considering EFI but need more performance as well. Moving the t-body isnt going to do anything when the CIS is upstream of it providing a restriction too. There will be some fiddling involved when I do the cams due to the CIS being sensitive but ill get past it and make it work. If a full rebuild was an option on your car Frank, I have a list of internal changes that would make your car a reliable powerhouse with the stock look.

 

I recently put together a package for a BBi engine build with a target output of just over 400HP naturally aspirated. The major internal parts that would be replaced are the pistons and rods with custom components. The cams would be re-worked to a performance grind, the ports re-worked as well, special valves then the usual rings, bearings, seals, bore and hone, balance....etc, plating and so on. Provided the engine was already out of the car and seperated from the gearbox, the cost of the build would be roughly $17K cdn. The engine simply would not ever break, no blue puff on startup, no oil consumption to worry about, no valve heads falling off, no worries just an awesome killer engine.

 

This is the type of rod I use in almost every engine I build, they support 700HP which is overkill but they look oh so nice dont they? Plus they can spin to 8000 rpm all day long at 700HP, they can be made to support 1600HP with different materials and hardware if the need be such as in a twin turbo TR powered boxer application....hint hint. They simply wont break or bend.
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http://www.popularhotrodding.com/tech/0311_phr_compression_ratio_tech/index.html

Nice mix of things. Interesting how they strongly link the cam to capitalizing on increase in CR.

These are probably the only mods that can be done "secretly" without blowing the originality. The Bad Azz Boxer had the right idea: take out the original motor (and trans!) and put in a 512TR and go from there.

 

The key to the best gain is always the combo and its the cam and compression that are tied to each other more than anything else. Its also the biggest error people make when selecting parts ending in disappointment. The BBi has a pretty good compression ratio right now (9.2:1), could be higher but its not useless for mild cam changes. 8.8:1 on the other hand just down-right sucks and is very limiting.

 

I've been reading Mel Nichol's book, FERRARI BERLINETTA BOXER per your recommendation, Paul. It's a great introduction to these cars and has plenty of useful specs. Although it doesn't cover the injected motor, it's interesting that the 512 actually LOST horsepower in comparison to the 365, even though it had 550 cc more displacement plus a 0.4 increase in compression. The 512 cams must have been pretty mild and I imagine going back to the 365 cams should really help wake the motor up.

How high would you go for a static compression ratio on the 512? Somewhere between 10:1 and 10.5:1? Who can make the pistons and how much? And is there a supplier for aftermarket cams for these engines, or is the best solution (aside from finding a set of 365 cams) having the originals reground?

 

Glad you got the book, its a good one and a must have for boxer fans but its old so it doesnt cover the injected cars and it has some mistakes like using a heavy chain under the rear cover to drive the gearbox, things like that but its minor. I cant think of any books that do good coverage of the injected cars, you have to buy a book on ferrari covering several models to get the BBi coverage.

The HP difference is due to RPM redline being higher and cam selection, shorter stroke but torque is less than the 512's. On a carbed or EFI converted car I would run 10.5 - 11:1 and select the cam grind accordingly which would be farily long in duration to cut down the effective compression ratio allowing 94 octane fuel. The car would be a rocket. On the CIS cars there are more limitations so I would keep compression down to 10.5:1 run less cam and maybe change t-bodies, mess with the exhaust and serious head work. Again the car would be a rocket and best of all it would have the most torque (at a lower rpm) out of all the boxers due to intake runner length being the longest. The car would be a rocket too but it would be more usable, more friendly.

 

On the BBi's, does the CIS ultimately limit the airflow compared to the earlier carb'd cars? Is that why some BBi's, as you mention, benefit from being converted to EFI?

 

Yes its a restriction but unsure of the loss unless we did a back to back test on the same car. The cams are fairly flat in the injected car too. Some argue its so the CIS wont have calibration issues, I say there's room for bigger cams and that the cams are part of the CIS package used together to meet the emission requirments. They changed from carbs for smog reasons so it only makes sense that the cams would be contributing to that goal rather than a requirement for the CIS to work. My car started losing power at just over 6000rpm but I spun it to 7K on the dyno. Different cams would change that by extending the power curve unless ferrari with their protractors got the cams and CIS restiction perfectly matched - I doubt it. The 365BB cams I have for my BBi will increase power for sure, then David is toast in his 365BB!

 

Not until the 308 is done I dont think. Ill take an ear full otherwise, lol. I still have to collect a few more parts as well and I might find myself in the middle of a powertrain restoration with a case of the "while im there"......which would include a top end build etc....Ill know better the closer the 308 is to being done which is the spring.

 

Also, regarding other subtle mods, how much do Ferrari heads realistically benefit from porting, polishing, and port matching? Modified production-line engines like SB Chevies can see 50 HP or more just in headwork, but I have to "assume" that Ferrari motors, being assembled to a much higher standard, would gain far less. Of course, if you're the one doing the grinding and you know where to grind, whatever HP you get is free anyway.

 

They arent like chevs in that way but they do respond to porting and other mods. On a boxer for example the head evolved from a daytona head but they changed the outlet angle of the exhaust port making it worse than the daytona but the intake side port is better. I would concentrate on the exhaust ports as well as valve size and design for maximu flow. The other area where ferrari has always sucked is the 4 ring pistons, garbage garbage garbage, what a stupid design - its not a compressor. Toss them and add a modern 3 ring setup with higher compression pistons and the oil consumption would go down, power up, weight down, nothing but an advantage.

 

pankel rods, forged pistons, aggressive cam grind...and you are on the way!

 

These are the JE pistons I had spec'd for my BB...
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david,

what is the approximate cost on those pistons? what is the change in compression and has the performance been noticably improved?

your car was a fast boxer to begin with...as i recall!!!

pcb

 

Pretty and 3 rings as it should be! The stock rods are OK but not fantastic, the rod I posted is a manley. He needs stuff like that just to keep up with my BBi.

 

Pete,

The pistons, with rings and pins were less than $1,100. If I recall correctly, the complete assembly was more than 100 grams lighter than the stock set-up. In addition, we did some clean-up in the heads particularly around the exhuast ports, matched all the ports to the gaskets/manifiolds...as well as some light clean-up/polish in the intake manifolds. Heads were cc'ed, as well. Compression bump was just over 3 points....

The biggest difference is improved driveability at lower speeds...and near zero smoke on start-up. Fun factor is way up.

The BBi cars still pose a threat, but I do give them a courtesy "10 car handicap" for that 10-200 kph run. Perhaps after Paul figures out how to make his BBi faster, I'll have to reduce his handicap a little, so I don't fall asleep waiting for him at the end.

Onwards,
David

 

you tell him paul! it is a pretty fast 365 though!!

 

Pretty noticeable differences...
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I nearly coughed a meatball out my nose when I read that hogwash, lol. Strap your fiat down on a dyno and lets see some numbers there buddy!

 

I don't like the TRXs at 70mph, forget about 150mph.

 

Ive done 150mph on mine, im still alive.