Derek's 308 engine rebuild

So page B11 of the GT4 manual I have does indeed say you have to torque down the heads before checking the mains and it did work. I plastigauged them all-- the big end ones were .0015" and the three middle ones just above .001". When I cleaned off the plastigauge and coated the bearing surfaces with moly grease, the cranks went in nicely and I got 5 thou end float using one std thrust pair and one .25mm pair (on the flywheel/thrust side.)

I slowly torqued all the nuts and turned the crank by hand after each step. All went well until the final step on the 4th bearing when it tightened noticably. All the others torqued up nicely and no tightness on the crank. I turned it a few times with all torqued down and in the morning I'll see if there is any indication on the #4 bearings where it might be a bit tight. I might need to polish that journal a bit or it might be a bit of oxide on the cap or crankcase that didn't come off in the cleaning.
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So it was quite obvious where the #4 bearing was tight. It was at the back edge and when I got the micrometer into the edge near the radius, it was about a thou bigger. I'll get it polished down by my local machinist. After Xmas I'll give him the block and torque plate to bore the liners to 81.25 for the new pistons and leave him the heads to line the valve guides, cut the seats and maybe lap in the valves.

The Total Seal rings arrived and the order taker wrote 81.25mm as 81.025mm so they will have to go back.

Merry Christmas to you all!
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Just to clarify, the crank journal was about .0005-.001" bigger at the back of the journal near the radius. Hard to get the micrometer in there but I checked with my caliper locked and it was slightly tighter near the rear journal radius on bearings 2,3, and 4. I should have found some more plastiguage and done the full width of the journals (I was down to a few cm so rationed it.)

My guess is that the grinding wheel wasn't dressed perfectly and the face wasn't flat. Worth checking everything a couple of times

 

I've now measured two of the conrods and it seems the Superformance bearings are a bit big. I torqued them up and got 43.46mm on both rods. My crank pins were ground to the upper limit for the first undersize (43.38mm) and this would give me 0.08mm (.0031") clearance which is right near the assembly limit and too much for my liking. Has anyone else noticed this? Anyone know who is making better bearings? These were no-name, no country of origin, brown box and from Australia according to Superformance.

 

Just and update from my separate rod bearing thread. It seems the bearings from down under are sold by many vendors and are not always within spec.

I've now checked all my conrods and a few have ovality (longitudinal stretch) of over .001" so I'll get them all resized to the lower end of the specs (47.13mm), and recheck the ID with the Superformance bearings torqued in. That will probably lose me the .001" clearance I'd like to lose. If not, Alfredo at Dinoparts has confirmed his German-made bearings are 1.845mm thick.

Interestingly, one of my big ends was 47.11mm. The factory tolerances continue to surprise me. Anyone have a good set of conrods they will sell swap for new valves Might be cheaper than resizing mine.

 

I pulled out the old wrist pin bushes this morning. Normally I'd use a vice and press then out but the vice is in my unheated garage so it was warmer to do it on the kitchen table with a long bolt and two sockets, one with a 21mm OD and one with a 22mm ID. I'll press the new ones in with the vice as it's easier to keep everything parallel. I'll use two old bushes and an old pin to press in the new bush.
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I spent a few hours looking into buying new rods. My originals will require re-sizing BE $25, fit/hone new bushes $25, new bush $10, 2 new nuts $10 = $70 per rod. Or I can get new H-beam rods for about $100 each (125 with ARP bolts.) I'm sure both will easily outlast anything I will throw at them but the new rods will not have approx 2 million cycles on them. The originals are about 30 grams heavier which is minimal. The H-beams are a Honda 4-cyl rod good for 9800rpm and 700hp in a boosted 4-cyl! Decisions, decisions...

 

The block is now ready for boring. I had the brilliant idea of cutting the old wrist pins in half-- they would have worked well as spacers on the head studs but they are so hard and cutting them square with an angle grinder would have been difficult. I just used some 5/8" nuts and washers to act as spacers.
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I re-sized the big ends to 47,130mm and the crush of both old (original std) bearings and the new .010" bearings is at .010-.011" on all rods. This seems a bit high. Does anyone have a good recipe for bearing crush calculation (as a % or diameter etc.)? I haven't seen anything in the manual. I recall 4-6 thou as a guideline.
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I have some pretty big news which has kept me busy the last few days looking for schools in London (UK that is, not Ontario.) We will move in August so any Brits out there know of car storage that won't break the bank? Maybe out in the countryside in a barn with a cat. I would really like to take the 308 with me but obviously won't be driving it around central London. We will have a lovely old flat in Marylebone but sadly only on-street parking.

I had some steel machined down to diameters of 47.13mm and 21.5mm (with an 18.5mm section at the end) so that I could measure the parallelism of the big end and small end. The section at 18.5mm was to allow a similar check with the new aluminum bronze bushes pressed in. I'll have to buy a hone or an 18.5mm reamer as once pressed in, the wrist pin bushes are a little tight. All rods were surprisingly parallel (well within the spec of .03mm at 50mm, page B16 in the manual.)

Does anyone else want some H-beam rods at about $90-100/rod. I'm still thinking of getting some made and have one other person interested. They will be the same as all the other 4340 H-beam rods coming from China (Eagle etc.) with aluminum bronze bushes, twin oiling holes at 4 and 8 o'clock and made for the 3/8" ARP bolts (200-6209.)
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I try to do a little bit every day. I brought my vice into the basement and pressed in the other seven new pin bushes and drilled the oil holes. The old rods are looking pretty good now so I might just get new ARP rod bolts and use them (the 126-6101 Alfa GTV bolts suggested on this forum.) I haven't heard or read of these rods ever breaking and they look fairly sturdy. I did notice that two are "C" rods and the rest "D" so I'll balance them all end to end.
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Here's a really good option for rods and rod bearings-- wish I'd found it before. There are King racing and Clevite bearings for a Suzuki G15/16 that could go into the new rods that would be .005" undersize or .015" undersize. These are both very good bearings and both sets would be under $100. I'd rather not grind another 5 thou off my 348 crank but wish I could have only ground off 5 thou to start with.

I may go this route with my 308 crank which I don't need and sell it ready to install with new rods and bearings. Any takers? I could put it in my container to the UK for anyone in Europe doing a 308 rebuild.

 

The Suzuki rod big ends are 47.018mm ID and the 308 is 47.13mm so you could also get your big ends resized .112mm smaller to take the King, Clevite or Federal Mogul bearings. The tabs are on the other side of the parting face so new tab slots can be cut.

Superformance have agreed to take back my Australian rod bearings despite some marks from fitting and measuring. I'll get the 10 thou German bearings from Dinoparts for my 348 crank which is already cut to .010". ACL Bearings was the last Australian bearing manufacturer and they closed several years ago so hopefully this old stock will soon be gone or people will grind to suit the bearings they get and not to suit the specs-- my mistake not measuring the new bearings torqued in before taking the crank to Montreal for grinding.

 

While waiting for my block, heads, and 348 crank to come back, I found my 308 crank (eventually) and it is perfect at standard mains and BEs so I will not grind it. Even the old bearings look very good for 58k km. I ordered a cheap set of Suzuki G16 rod bearings just to have a look and see how well they fit-- $12 for 8 shells from ebay. Funny coincidence is that they are ACL so probably came from the same defunct factory in Tasmania as the Superformance rod bearings. The difference in size might account for the extra 1 thou clearance... It will be interesting to see if they are indeed the same.

My body is finally ready for paint-- they got a very good paint match to the sides of my headlight pods (which had no sun damage) using Dupont/Axalta so I'll get their recipe for Grigio Ferro in case anyone else needs it. The colour part was easy but the exact match to the metallic particles took 6-8 tries to get an exact match. Now they are waiting for the weather to get above -10C so that their heating system can cope.

 

I was going to fire up my home-brewed ultrasonic cleaner today but filling it up I noticed a few small leaks so have to wait for it to dry and then re-seal the bottom. My high-tech solution for sealing the stainless plate on the bottom is a combination of my bird-dropping-like tack welds from my $100 flux-cored MIG machine plus silicone. I may need to use some epoxy instead or pay someone to weld it up for me.

The CAT cams arrived and are lovely. I noticed that the original cams have what must be tiny oil holes near the start of the ramp but not the CAT cams. I haven't seen these oil holes before and have always thought the oil flying around in there was sufficient to lube the lobes.

The special springs (on right) are a bit softer than the originals and fewer coils to allow for higher lift. They fit the original retainers.
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Since my ultrasonic cleaner isn't working yet I cleaned the manifolds the old fashioned way-- degreaser, brass brush and laundry detergent in our laundry sink. I noticed that the degreaser spray plus the hot water and some laundry detergent made a very nice soup to soak the manifold in overnight. In the morning it just needed a little more scrubbing to come out shining. Just a bit of gasket left to remove with gasket spray and a plastic spatula.

There were clear signs on two runners of coolant getting in and a bit of corrosion on the one flange.
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I was on tenterhooks yesterday as the body was finally being painted after nearly 3 months at the body shop. It turned out really well!

Al was waiting for a warmish day so that his booth and storage area were the right temperature. He prefers to paint metallic paints already assembled so that the doors and other panels are in the same orientation and get exactly the same treatment. I probably wouldn't notice the slight differences but he is a perfectionist. It will now sit in the booth for a week to dry while Al heads south to spend all my money on bourbon and po boys in the big easy.
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Just in time for the year of the rooster, the new cam pulley samples arrived. The design is a little lighter than that black set I got and has a smoother transition inside from the flange up to the outside which reduces stress concentrations. They sent both hard (type 3, bronze) and the regular type 2 in red. Both are 7075-T6 aluminum. I will ask if they can print 360 degree marks of the guide flange to aid timing and might get more timing holes-- 25 degrees apart on one side and 24.5 on the other. If anyone wants a set I need to know what colour and how many in the next few weeks US$320+shipping per set of four.
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Jeff, I used the Gunk spray, let it sit there for 15 min and then scrubbed with a soft brass brush for 5 minutes while I filled the sink with hot water and liquid laundry detergent (lavender scented in case that was relevant Soaked them a few hours, then more Gunk and brushing. The Gunk mixed with the soapy water and the combination may have worked well together. I left them overnight. Another 5 minute brush in the morning and they were done.

The spray-on gasket remover is not that great on the remaining hardened old gasket bits. I baked them at 200F for a couple of hours and carefully used a very sharp blade which worked a bit better.

 

No Brian, I was thinking about the round-tooth sets but I only had 3-4 sets requested and need at least 12 to cover the NRE costs and effort. They would be $480 for a set. Any takers? I still have lots of valves left as several people who initially expressed interest went quiet so I will take deposits on the cam pulleys so I don't get stuck with lots to sell on ebay.