fitting different cams in a 308 2v

With a 2v injected engine your options are very limited as the injection system is sensitive to what it can operate with. With stock compression ratio you are also limited. Does the shop in question have cams that they know work well with these they have recommended? There is some performance to be had in doing this and remaining within the window of what works with this injection system but it's pretty narrow.

Increasing performance with these in stock trim is IMO best done by changing to EFI. I want to say the easiest ECU to do this with now is from Holley. Others may chime in on this, but Holley's is incredibly easy and has self-tuning functions. It is a worthwhile conversion as it eliminates quite a bit of plumbing resulting in net airflow gains thus performance as it's getting air straight through the throttle body with no stops between. There is a bit of work and some fabricating involved but it has been done many times. No more Jetronic nor ECU failures/start up gremlins ever again. You can also use the early 308 carburetor engine cams with EFI, or bump compression in a full rebuild and run whatever cams you want that will work with that compression ratio. All ignition/fuel tuned on a laptop

 

Not sure that there is much upside to doing the valves on a UK 308 - it seems to relate more (but not exclusively) to fuel burn characteristics of US gas - just because the engine is out to do the gearbox is not a great reason for a tear-down (contrary to what a lot of posters here suggest) - having said that SMDG have probably seen a lot more 308 engines than me

 

It is the case. Take their advice.

 

Many years ago I worked with Ron Iskandarian experimenting with cam shafts in a then new car with CIS injection. We ran into a solid wall very quickly with overlap and CIS. There was simply no way around it. The physics of it will not allow reversion and most manufacturers use very near the maximum. Carb engine cams dont work.

Big improvements can be had with compression but not cams.

 

If you hang around here long enough and listen to enough of the wrong (self appointed) experts you will discover 3 things.
1. Timing belts never break.
2. Sodium valves never break.
3. Testarossa transmissions never break.
Its all a scare tactic to help crooked mechanics earn more money.

 

As a side note. Holley EFI is self learning on only one table. There are many tables and professional tuning will be needed. Especially if it is a 308 conversion as that is not something in the Holley tuning wizard. You can use the wizard to get it fired up but it will need extensive tuning and it is best done on a wheel dyno.
Still a great option, just not self tuning.
Even in a small block Chevy, the self tune is not going to get you the performance you want. Even after it is tuned, leaving the self learn on can trash a good tune. Best to just have it tuned and leave it.

 

@Rifledriver does the QV run off the same CIS? Does that mean they have the same cam limitations? That would only leave this for carb cars.

@Boaty_Tom the performance cams are out. BUT a good improvement could be a electronic ignition system whether Petronix or MSD. There are a couple direct fire systems as electromotive went under, but again, that adds more complexity. There isn't a lot of performance to get unless you do a lot of work on the motor - but there are guys on here doing it. It's just very very expensive.

EFI is a lot of work but a lot of reward. I am about to purchase my stand alone system (haltech or Link) and I have done a ton of studying on the systems and tuning. There are so many advantages with EFI but they all come with more work and customization. If you really want to dork out with tuning and get some balanced performance, it isn't just about setting up the computer. You can get into individual cylinder tuning with wide-band sensors and exhaust gas temp sensors for every cylinder. It's a rabbit hole.

 

It has been my understanding that a set of earlier carb Intake cams can't work with our CIS cars.

But what about an earlier pair of Exhaust cams in a CIS engine?

Due to the well documented sodium exhaust valve issue, I would not want to risk a more aggressive Exhaust cam design with them.

But if the OP will be swapping these for solid exhaust valves, then, would the use of a pair of higher lift and/or duration Exhaust cams alone become of potential interest?

DM

 

How will that change anything? Do you know what overlap is?

 

Actually, I think crank fired ignitions simplify the spark system as they eliminate the distributor(s). They are also a lot more accurate and stable.

 

Eliminating a distributor is never a bad thing. They are rather Victorian but contrary to an earlier statement it will not make an engine more powerful than a proper functioning original ignition system.

 

Replacing sodium valves is an interesting one. Its super expensive when they fail. It doesn't happen often. I have seen on here that Ferrari advised replacement after 40K km to replace them - so there's that. Would I do it?- I was about to and I already bought the vavles. I was going to do them all, because why not.

Only the exhaust valves are sodium filled. These were sodium filled because they dissipate heat better (exhaust is hot). This was done amongst many sports cars, but Ferrari's valve design was much smaller and thinner in diameter that over time they were more prone to this failure than other manufacturers that have more beefy valves. In a way it is good because in engine design, it reduced weight in the valve-train (or rotating mass or however this is measured) to get better performance, but it was unforeseen and not thought of as these cars would be in existence 30 - 50 years in the future. It would really be on the mechanic and machinist to redo / replace the intakes. Here's an old thread with some x-ray pics! https://www.ferrarichat.com/forum/posts/146357453/


HOWEVER... (big one with sigh)... This is an expensive "while your in there". If you are taking the time to do heads, if you only replaced the sodium valves and nothing else, you would be doing yourself a great injustice by not addressing a number of areas, especially since you are not going to be taking your heads off commonly. Taking heads off is expensive, but doing it again for something else is even more.

1. Confirm the valves in there are the sodium valves - I am not sure of the exact way to determine but i am sure it means removing the cam cover, camshafts, cam bucket (and shims) and some sort of magnet test on the valve stem - it would be great to have a real "how to identify sodium valves thread".

If so, go forward with the project!

A full head job will include removal and inspection of assembled head for parts in motion - easiest with engine out but can be done in the car.

full head disassembly -inspection of wear on all parts and surfaces

Full inspection of camshaft and wear to determine if they are still in spec or need to be reground or replaced.

Inspection of combustion chamber surface / dome ( in case you didn't know, 308's are Hemi's - so you can joke with all the mopar folks)

Inspect for any warping - if so, there will need to be machining

Inspect for damage like cracks - mostly visual but if you really want to do it right, there are chemical tests like magnaflux. This process costs more but is more accurate.

If there was never any valve replacement - it would be good to remove and replace the valve seats (the ring the valve closes on) as the cars were built to run on leaded gas - replacing these allows you to run unleaded without additives. (leaded gas meant softer impacts on the seat)

HERE is your answer in my long winded fashion - you can replace all the valves if you want to. the intake valves are not known to break. The upgrade you mention is the intake - it allows more air in for better combustion and i think the fillet profile or curve may be different. This requires additional machining in the head and this is where the real expense of the changes is - its likely way more expensive than the parts. It has been pointed out by the pro tuners on here, the 308 2v intake design is limiting. I wouldn't trust just anyone to do any porting without experience and proven results. In the end I believe this gives more torque - but how much? If anyone reading this can answer to make sure the juice is worth the squeeze, it would be great to know.

Also - good to inspect the cylinder liner walls - they tell a story to the trained eye. This is where it all could get really expensive if they see something bad...

Inspection and possible replacement of valve sleeves - best if replaced with quality manganese / brass ones - again more machining.

Reassembly -
Do you need new head studs? - new ARP ones are the way to go - probably $150 - 200.

New head gaskets - the good ones from Elring these are $500+, the Cometic is like $150 on the lower end. At that you need 2 head full gasket / seal kits which is another many hundred.

Replace the seals - either OEM or newer teflon or Vitton material. - guides and seals will eliminate oil in combustion and smoke in your exhaust.

complete vavle-train reassembly with proper valve clearance.

How do your cam covers look? its a good time to refinish / repaint.

Oh - New cam belts and tensioner bearings - just get the Hill Engineering ones


Whoa writing this is way longer than expected! That is the "do it completely / full overhaul". Anywhere you skimp on parts or service may just mean going back in. Hopefully doing it completely means you don't have to do it again. What does it cost? $10 - 20K depending on what needs to be done and if they find issues. And this is why these cars have deferred service and issues and sometimes a bad reputation. It just depends on how you plan to enjoy this car - is it a one or couple year thing or something you want to keep? And, it's a machine with moving parts, which means it could all break right after you fix it and you have to start over again. If I were planning on keeping it, I would do it. I would have to plan and budget for it. I might do a service with valve clearance / belt change and install the electronic ignition mentioned in the other thread. Service the brakes with new fluids / pads and new fluids all around, new tires. Check the suspension bushings and replace if needed. Enjoy the car then go from there. Then do the big job in a couple years. It all comes down to time and money.

I mean this is the both the best and most sarcastic ways at the same time - WELCOME TO FERRARI OWNERSHIP! It is what you make of it - if you enjoy looking at and coveting, preserving, doing your own work, making it original, concourse and showing, modifying and hot rodding, track driving and autocross, trips and adventures, saving it for special experiences or using it as much as possible. I will say - using the car leads to more maintenance but better running and usually more enjoyment. Magnus Walker says "get out and drive". I always liked Jim Glickenhaus's post footer quote on here "Not putting miles on your Ferrari is like not having sex with your Girl Friend so she'll be more desirable to her next Boy Friend." - if you don't know who he is, google his name and collection / new car company.

Oh to put things in perspective, her is a quote from my friend Cliff who sails and lives on his 50 foot blue water boat - "I could dump $50k into this thing and you wouldn't be able to tell or skim the surface of upgrades I could do. It just eats money and its always hungry!"


Cheers,
Spencer

 

You actually typed all that yourself?

 

You sure made a mountain out of a molehill. Maybe next time leave this up to someone who knows whats involved.
Posts like this just scare people away from simple jobs.