I bought this lower mileage c70 Ht- test drove it fiercely and ran good, but on the way home from the ]buyer[ in Oakland- threw a rod with no warning. Have been trying to find a 2.3 HT and I have the ability to try something new. Question is what short blocks are interchangeable with 99 2.3HT. I heard the c70 was based off the 850 platform and when exploring this forum found a member with almost exact problem but his was a 98- Same short block?? I know the 99 went to VVT but are the blocks the same? Any Ideas? thanks in advance BT

 

According to IPD's website, our cars have a B5234T3 model engine in it, while the 850 T-5's have a B5234FT and the R's have a B5234T5. If I'm not mistaken, the last two digits are just differences in the turbo, but the block is essentially the same. Also, the first gen C70's do have the same chassis as the 850, called the P80 chassis. You can check out IPD's youtube channel, they've got videos covering the differences and such, pretty interesting stuff.

 

Also, '98 and '99 has the same engine block. There are differences in the throttle system as well as some other things that don't come to mind atm...

 

98 only year engine has distributor etc, coil. Like old days. Short block same 98/99 for 2.3 HPT

 

Well after much searching for a good used 1999 2.3 HPT engine, came up with nothing but super high milers for over a grand. i Found a 97 turbo charged 2.4 engine core for free and disassembled. found it has same crank and rods (even casting#s same) and bearings as my 2.3 hpt motor, just the bore is different has oil squirters for pistons just like my engine. The blocks are different as the 2.4 has smaller bolt holes for front driver side engine mount, oil pan has front mounted oil cooler in front of pan instead of rear like mine, there are a couple of bosses for oil cooler attachment bracket bolts, but I think if you wanted to, you could probably put the earlier 2.4 in the later c70 barring Ca emissions issues. I know the 2.3 hpt is supposed to be a bulletproof block (I think I proved that! as it drove with #5 rod hanging out the side of the block for 1/2 hr till "I" shut her down) I couldn't believe check engine or oil pressure light never came on, even with a dead miss!
I used 2.4 crank, 1 rod, new piston, sleeved block, new rings, bearings and balanced assy. Purring like a kitten Thanks for all that replied, great group !!!