Thanks Maurice, I'm keeping the original pistons and using a replacement 81mm A stamp for #2 pot. JS , I'm replacing the main, thrust, big end and small end bearings. The liners are within tolerance and have been honed. All the bearings were in good shape except for #5 big end which had a scour in it but was still bearing on the outer surfaces OK. The small end bushes were ok too but had a little play and would have contributed to some noise so they'll be replaced. Trouble is the pistons and rods have to go to the machinist now and he's not the speediest. He had the block and heads for a month. Toys aren't a priority which is fair enough I guess. I'm happy with the work performed though although the parts came back with some sand residue from the cleaning process. I had to flush the block and heads to make sure it was all out. I hooked up a high volume water pump to the block had the worlds most expensive garden sprinkler for 1/2 hour. The kids loved it running through streams of water gushing from the V8, except when my 3 yr old decided to run under the block and hit a head stud on the way through! Cheers George
glad you didn't have to mess with new pistons really. Fitting new pistons to liners correctly can be quite the process sometimes. Just curious, what honing method was used to rough up the cylinder liners for ring seating?
I can relate to machinists not being the speediest - my heads took months. I think this will be a marvelous motor. If you do not want to get a carb synch, there is always the ancient hose and funnel method.
Funny you mention busy machinists. Locally, our best machine shop for European engines is at almost a zero day wait time. That's Las Vegas economy for you I guess.
ur going good george...... if it wasn't for me needing new pistons my rebuild would have been all over in 2-3 wks ross pistons set me back 7-8 wks bummer i said good luck mate!!
Thanks all for the support. JS, I'm not sure how they were honed, I think they just used a three stone hone but mounted, ie not using a hand drill. If I had my time again I recon I'd love to have been a machinist or fabricator. I'm always fascinated in how these guys do their thing and the toys they use to do it. Hi Karen, I really miss my runs down to Coolum and up to Cooroy News to pick up Octane. Should be back up and running in few weeks. Cheers George
When cylinders are in good shape and just need a rough honing, it seems that each machinist has their own 'voodoo' they perform that works for them. To each his own really. I am not a machinist, but every rebuild I have had where the liners and pistons were still servicable were treated to a flex-hone which is performed with a hand drill and has done the job quite nicely. I will probably be cracking my engine in the next few years and can't wait to make my own thread such as this! Great job
Maurice, I don't think my family would put up with me being moody for 12 months because I can't get my 308 fix. I say it'll be up and running in a couple of weeks but it'll probably be more like a month or two as the pistons/rods have to go to the machinst for balancing and small end fitment. I probably won't get them back for a while. I don't plan on doing the engine/parts detailing thing, just a good clean up and paint where required. I did the cam covers though as they had been painted red and looked a bit tired. I should have all my parts from Gerry other than the gear reduction starter on Monday. So I'll have a conundrum on monday night, work on the 308 or Top Gear UK ???? Cheers George
Well I've had a few hiccups recently. I got all my parts but when i looked at the new/second hand piston I sourced to replace #2 it was different to the other 7. Someone had machined my pistons to take thicker rings, all of them, so now I had one stock borgo and 7 dodgy ones. Thanks to Gleggy I now have a set of 8 borgos that look like brand new. See the pics, my machinist was impressed. So by the middle of next week I should get the rods back from small end fitment and I'm ready to start reassembly next weekend. In the mean time I've fitted the sump baffle mod. Cheers George Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
JS, Sorry it's taken me a while to respond. All the new pistons weighed within 1g of each other, all rods were within 2g so I've decided not to have the components balanced. This is just a street car and will only see redline once or twice a month for about 5 seconds in total so I'm not aiming for a race engine just one that's reliable and get's me back on the road. I've assembled the pistons and rods ready for fitment this weekend. I've also fitted new seals to the gear selector and put the sump pans back on. The new water pump has been checked for clearance and assembled. I've drilled a hole in the rear engine plate to relieve the gearbox oil when the 1st/Reverse selector shaft enters this housing. Apparently this mod fixes the cold 2nd gear engagement problem. It makes sense when you look at how the 1st/reverse shaft works. When shifting from 1st to 2nd the 1st/reverse selector shaft has to enter a guide in the rear engine plate. This guide would be full of cold gearbox oil and would resist the 1st/reverse selector shaft from returning to neutral. So when your're trying to grab 2nd from 1st, the selector fork for 1st would still have some pressure on it as it fights the oil filled guide. Once the gearbox oil got hot then the oil would be able to escape from this guide quicker. The mod is to drill a hole in the bottom of the guide to release any oil present, hot or cold. Hope it works!!! Other fixes have been to use thinner gearbox oil which I guess would also work but I wonder about the possible long term effects on the gear box. Anyhow here's some updated pics. Cheers George Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
good stuff. thanks for the pics. It's my understanding that several 308 motors were pulled for that very find regarding 1st to 2nd changes when cold. I spoke with the mechanic who performed this on my engine in '79 and did nothing else.
I was just lucky I stumbled across the 2nd gear mod on Fchat. I've had plenty of alfetta's that always have 2nd gear syncro problems but they are actually worn syncro rings. I've fixed the alfa's but then 2nd has been baulky to use anyhow. I didn't want to pull the 308 gear box apart just for a cold 2nd gear problem but I thought I'd do a search to see how hard it would be and that's when I found the mod. At first I couldn't understand how hydralic resistance on the 1st/Reverse selector could be the problem but I had an engineer mate of mine watch the selector shafts as a simulated a (very slow) 1st to 2nd change. What I can't understand (if this indeed fixes the problem) is why Ferrari didn't modify later rear cover plates. Mines a 74 engine but strangely the rear engine plate is stamped 78 so the orginal may have been modified then replaced at some stage. Hope it works!
Dear Sir, I think your decision to not have the rotating assembly balance is unwise. Most high performance street engines are balanced to half a gram. Almost 3 grams is a whole lot, especially combined with evenly moderately high rpms. I think this may be a case of pennywise but pound foolish. A question: Was your cam bent, or was the cam bearing cap somehow buggered? good luck
Just going by the 308 WSM. Page B31 - "The connecting rods must be of the same class, ie they must be marked with the same letter which classifies their weight. The eventual difference in weight should not exceed 2 grams." I'm sure 2g's in the rods will be OK as the engine was running perfectly well until foreign matter from an EMPI balancing tool destroyed it. The cams and good the damage was done by a broken valve head and the power of the starter.
im generally a bit surprised that ferrari would be ok with that much of a weight imbalance. But if you're comfortable with that, then carry on. One of the pictures you posted showed a thrust surface that was very angled. Im wondering why that was. thanks.
The thrust surface for the camshafts on all #1 caps is not parrallel. For some reason all four #1 cam bearing caps have been alloy welded and have had new timing marks cut into them. The engine has suffered at least one major failure in the past. At a first guess the caps were welded to reset the camshaft endfloat, trouble is the camshaft now only bears on some of the #1 cap surface not all. I'm yet to seek advice on wether this is critical or not.
Just an update, Pistons went in this week so I've been able to make a fair bit of progress. I got my first lesson in piston installation from my mechanic neighbour. It's been great having him help me out. I've been slowed down due to some incorrect seals that I'll have to change and I still don't have my cam belts and starter, hopefully due next week. I'll put the camshafts in using the old belts just so I can keep going and then replace them when the new belts come in. In the mean time I'll pull out the two coolant pipes that run in the chassis tubing from the engine bay to the radiator. Just a bit of insurance to make sure they're ok. I'd hate for them to fail and have to pull the engine just for a leaking pipe. Cheers George Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Damm I thought I was almost there, I measured my cams and found they were badly worn and had uneven in lift values. So it's off to the cam shop for a regrind. I posted a separate thread about my cam problems. Another couple of weeks now I guess.
