How does a winter project become a rush to make Dyno Day in mid-May? Read on curious one . . . it’s a long story!
Late in January my car died suddenly and I had it towed to Speedworks http://www.n-e-c-c.com/forum/viewtopic.php?t=936
They determined that it was the distributor on Feb 4, but I also needed a new timing chain, so I decided to leave the car there and get everything done at once. Neil had an SR20DET from a Bluebird SSS Attesa with 40k on it from someone’s abandoned project sitting in the shop and he offered to install it for me. That would take care of the timing chain and the distributor, not to mention adding a turbocharged motor with low kms.
Neil said “I can’t see any reason why it would cost more than 5G”, but that was not the same as “It will cost 5G.” Also, he had never tried this particular swap before. He would have to find a good FWD SR20 tranny and fabricate custom mounts for the motor. On the other hand, I could have the KA24DE completely rebuilt to higher compression, with a mild port polish and a slight overbore, for similar cost and all the parts available off-the-shelf.
After some research into SR20 swap vs. rebuild vs. short / long block, I finally decided on having the engine rebuilt locally. That would give Speedworks more control of the project and also we would know the condition of every single part of the engine. After adding a few details like stiffer motor mounts, constant radius intake piping, high-flow cat, and ceramic coated header, the initial estimate came to just about 5G.
I put down 2G deposit on Feb 16 and that is when the fun began . . .
We found out that although the Altima’s KA has a stock compression of only 9.2:1, its pistons have the same part number as the ones from a 240’s KA. Different head? Anyway we looked for cast, flat-top, overbore pistons for the Altima or 240. One supplier said that he could get them. A week later, he said he was mistaken and no such pistons exist. One week wasted . . .
Instead we ordered cast, dished, overbore pistons. To compensate for the dish, Neil was going to raise the compression by using a thinner head gasket and taking some off the block and head at the machine shop. Not too much, so the timing chain geometry stayed within spec. We waited for the pistons to arrive, and then sent everything to the machine shop. We had to wait for the shop to get around to my stuff; they were very busy. When they finally looked at the parts, they found out that the supplier had shipped us standard bore pistons in a box marked overbore. One month and counting . . .
So Neil called the supplier and said WTF, send us the right pistons. But now they were back ordered! Neil tried some other suppliers including Nissan, but it seemed like there were none available in all of North America. They would have to be shipped from Japan in 4-6 weeks! By now it was near the end of March, so I decided to fork out an extra $500 and get the forged 10.5:1 Wiseco pistons. These only took two weeks to arrive, still it was April 14 when we finally sent everything to the machine shop again. On April 16-17, Speedworks had a break-in, so that was grrr8. Two months and counting . . .
The stuff came back from the machine shop during the last week of April, but Neil was busy with a custom-built Subaru motor by then. I suppose I could have made a big stink about it and demanded that he work on my engine first, but I decided to be patient. After all, what’s a few more weeks when I’ve already waited nine? I hope he remembers this grace period when it comes time for me to pay the piper . . .
Anyway, he finally finished the Subaru motor last weekend and started assembling my motor. He avoided cutting valve reliefs into my new pistons by using a thicker head gasket. The bottom end was pretty much done on Monday, and the head was bolted on yesterday. It turns out that the timing chain we received was the wrong length, so now we are waiting for the correct one to arrive from down East. Kinda ironic, because the timing chain was the whole reason I started this rebuild . . .
Well, if the chain arrives tomorrow, Neil figures I should have the car back on Friday. If that is the case, I will bring it out to Dyno Day to get some wideband data. No crazy WOT stuff yet, just some “ramp and hold” runs to see how the computer and injectors are adjusting to the changes in IHE and compression ratio.
IF YOU MADE IT THIS FAR, THANKS FOR YOUR INTEREST AND SORRY FOR THE LONG POST.