Hi, I have a couple of questions I thought I would ask before I begin reassembling my 1977 308 engine. My engine has been in pieces for about 4 years now, and I figure its about time to reassemble it. Over the past 4 years, I bought a bunch of stuff in hopes that I could build a more powerful engine. Wanting to increase the stroke of the motor, I exchanged my 308 crank for a 328 crank. I purchased the crank from T. Rutlands who had it checked and polished at a machine shop prior to its delivery. Next I sent out my connecting rods and cylinder liners to Concours Automotive to have a custom set of JE pistons with 10:1 compression made up and fitted to the cylinder liners. The pistons have a raised wrist pin location to accommodate the increased stroke of the crank. I didnt check this myself, but supposedly Concours Automotive set the piston to wall clearance at 0.0015. This number seems a bit tight to me, but I was assured that this is a good fit for these pistons. The pistons, pins, and connecting rods were all balanced in the process. Heres my question. Both T. Rutlands and Concours Automotive told me that I did not have to do anything further regarding balancing and that on the 308 engine everything is balanced separately. On the other hand, my local machine shop says that I need to bring everything in (pistons, connecting rods, crank, flywheel and harmonic balancer) and have it rebalanced together. So whos correct? Does it have anything to do with the fact that the crank is a 180 degree unit? Do you think that 0.0015 clearance for a JE piston is reasonable? It took great effort to pull the cylinder heads off and there is some corrosion and small pitting on the head studs. Do the studs need replacing? Theyre pretty much frozen on the block so I would probably need to heat them up with a torch. Any advice would be greatly appreciated! Alan Ing
i work on jets and muscle cars so take my offer of help with a grain of salt since i dont ( yet ) own a fcar. i have built quite a few engines and i would have EVERYTHING balanced as your shop suggested, these are expensive parts and much like paint work, the preparation is critical to performance and long service life. throwing a bunch of parts together is not a good idea, even if they were meant to work together , if just one is out of tolerance it could be a problem you dont want to have. i swear by ARP stud kits for my muscle cars, way better than stock. i have no clue if you can get them for a ferrari v8 but i dont see why not. since you are upping the power i would repectfully suggest you replace all fastners and hardware since aluminum is unforgiving and everything is 20 or so years old (from factory new ). i plan on getting a beater fcar to learn on and take apart as necessary, please post pics and keep us posted on your progress. ATLANTAMAN seems extremely knowledgeable, perhaps he can help you if his schedule allows. if you are modding the bottom end you want to make sure the heads, carb and ignition/ intake can keep up. engines are just big air pumps and you must balance the flow of air and power in and out . best wishes, michael
The 180 crank is the reason they are saying you dont have to balance it. Unlike a 90 degree crank in a domestic car for example, the piston/rod assemblies cancel each other out. Provided they weigh the same as each other. Yes, you could have the counter weights cut down or have weight added if you were running the 24Hrs of lemans to gain the extra 10th but I wouldnt bother. I would think there is a limit to how much you can change the reciprocating weights before a balance is required but I would say you are safe. I built my 308 engine 2 years ago, put in custom pistons that weighed 400grams less than the originals and the machine shop told me not to bother balancing it. I didnt and its seen 8K rpm many times and 15,000kms use without a problem. If this was a SBC it would have shaken its self to death by now because of the crank design.
.0015" is a good number for the piston clearance. Balancing may help and certainly won't hurt, but is not required.
Thanks for everyones thoughts. I guess I'll pull the head studs out and replace them. It looks like its going to be a major pain. Any suggestions on how to do it? An acetylene torch and a breaker bar? Its a relief to know that I don't have to rebalance everything. In Hawaii we don't have a lot of machine shops and fewerer who are comfortable working on Ferrari engines. While my engine block is relatively clean (I pressure washed it), I would like to remove the surface oxidation from the engine case. Bead blasting is definitely out, but would soda blasting be a safe thing to do?
according to my info, the 308/328 crank, damper, etc are all balanced seperately---BUT how close, one never knows--it is not a lot of money to have the assembly balanced again as a whole. I had my 330 done after I lightened the flywheel. Think it was only about 200.00 PS the clearance all depends on the type of aluminum is in the pistons--my old 330 pistons were non-silicone venolias and required .007" new silicon/aluminum pistons can fit a lot tighter since thew swell less
I cleaned mine by pressure washing, then parts cleaner, then paint remover to get rid of any baked on oil, then aluminum wheel cleaner (a mild acid product) and it looked new. Blasting might have been faster, but I always worry about getting stuf in the oil passages. I gave up on getting the head studs out, even with the block quite warm, they showed on interest in coming out.
I needed to flat the decks on the block so the studs HAD to come out. Out they came with reasonable effort, lucky none of them stuck, and I really don't know why. THe 180 crank did not have to be balanced, but the pistons, rods, and bolts/nuts were balanced separately to 2 grams. Good enough for me.
a small drop of battery acid usually does a great job at freeing up the gunk around the studs and gets them free
an engine builder once told me that if i could not get a stud out---apply a small drop of battery acid around the threads and wait over night--it will slowly seep in and eat all the corrosion and bacteria etc that is locking in the threads.
That sound too tight to me. It may be O.K. for a small bore though. Call J.E. Pistons and ask them. They are in Huntington Beach, Ca. You should have a build sheet with these pistons giving you a job number and specs. If not, they should still be able to give you the info you are looking for. Rick
Check with the piston manufacturers - but sounds way too smaller clearance, the clearance for standard pistons is between 0.020mm - 0.060mm MW
Did you try this yourself? On the 308, the threaded section starts at 2 inches into the hole, and continue for about 1 inch. A drop of acid travels far enough down there?
--have not tried the acid yet--did not learn about it until dumbas* here broke 4 studs and had to weld on big nuts to get them off---what the heck--was planning on replacing all the studs anyway thankfully I have a machine shop at my disposal ddooooo!
Sorry for the late response (I've been working to hard to check the forum). Thanks everyone for your advice. Your suggestions are greatly appreciated. I spoke to Mr. James Patterson from Norwood Performance in search of the ARP head studs that are mentioned in the 308 engine rebuilding article in Forza. I tried ARP, but they don't have a listing for the 308 motor. Another Rep. told me that they don't sell ARP studs for the cylinder head yet, but they might do so in the future. Anyway, James was very helpful and told me that since I am not putting a Turbo in my motor, the old studs should be fine (even with minor pitting). He further recommended that I remove the studs anyway and clean them up. Thank goodness as I called a Ferrari parts dealer and was quoted $70.00 a piece for OEM studs!!!!! As another point of information to add on to eveyones suggestions for removing the studs, James said to remove the cylinder liners and aim an acetylene torch with a rosebud tip on the portion of the block that encases the studs in the water jacket. Just thought I'd pass this information on as another method one might use to remove the studs. In the Forza article, James suggest using Gask-a-Cinch on the cylinder head gasket. Has anyone tried this on aftermarket elring cylinder head gaskets? I think I might do this as my cylinder block and cylinder heads have some minor pitting on the surfaces. Regards, Alan Ing
The professional would shoot me for this but ... at $70 x 20 studs, you might as well buy another block. So, I would 1. clean it up as best you can 2. Leave the studs alone or you are sure to break some of them 3. then install the head gasket with K&W copper spray.
YEL--330 blocks are hard to come by---and yes i ended up replacing all the studs--but the studs and nuts form TRutlands were only about 15.00 each if I recall. But now that I have a CNC lathe I can make all I want for a lot less
Atlantaman, I thought ALan was talking about a 328 block. And, a 330 would be hard. By the way, you can make those hardened studs yourself, now?
Uhhh, T. Rutlands quoted me the $70.00 per stud which nearly floored me. The allferrariparts.com site had them for $20.00 a stud which seems a lot more reasonable. A CNC Lathe????? I want one!!! I'm lucky that I have access to a small machine shop that I helped set up. We have a 9" x 49" Taiwan Bridgeport vertical knee mill knock off with a 3 axis Video Readout and a 13" x 40" Taiwan lathe. Someday I want to purchase an old CNC milling machine and upgrade the electronics for a PC. What do you make on your Lathe? We mainly machine parts for a national robotics competition (Sorry, not battlebots) that I help out with. Alan Ing.
I have Aero space Cylinder head fasteners (& other fasteners) available that have been engineered & designed to handle the Ferrari 308 4 LITER (YES 4 LITERS!) which is done by a Modular Integrated Deck design & custom Crankshaft & bore size currently being completed. These custom head studs come with a 12 point nut & washer & are designed to handle more than most people will put there engine through. (Turbo,Nitrous etc.) They will also work on a standard 308 engine. When you remove the studs make sure that you remove all of the foreign material deposits & then chase the threads with a thread chaser or you are just wasting your time. Crankshaft re balancing is not necessary because its a 180-degree crank. If you are just replacing pistons & rings you do not need to re balance, if you were going more extreme, I would recommend it just because its not much money to have done. I have balanced to 1/10 of a gram just because, (not necessary). Always follow your piston manufactures recommendations & build sheet, obviously if you ordered a set of Ferrari pistons & rings the manufacture realizes that those tolerances are critical, if you have questions or concerns contact them again ask them why, they will give you a explanation. There are different alloys being used in Piston & ring manufacturing today than years ago so tolerances change. Never bead blast any part that will be in contact with the internal oiling system of the engine. Ferrari chats oldest Sponsor www.nicksforzaferrari.com
A note of warning, if you buy after market studs make sure they are made from the correct material - the ideal tensile strenght should be close to 10.9, any higher and they could snap, any lower and the threads will strip. If you want original studs we stock them for $40 each. MW
HEY Nick!!!!!! Were have you been hiding dude? It's good to see you posting again. Hows the 4.0L project going?
YEL-- I think he was was talking 8 cyls--but the motor that I snapped my studs in was a v12. I ordered a batch of hi strength steel for the studs--dont recall what it was--maybe 9210 sae-- all of the newer studs that I see all have cut threads where the 30 yr old ones have rolled threads. I cut mine to match the once that i got from TRutlands. They should be fine...now if i can just locate a new set of 330 heads
