1987 civic motor question

[dazzlesa]

is the 1.5 motor that is in a itb civic the same as a itc civic. i know that one is fuel injected and one is carberated. is there any other differences?

[bamfp]

The pistons and the cylinder heads are different. The ITC Civic engine has a CVCC head.

Blake

[R2 Racing]

Blake's right. The heads are entirely different since they have the CVCC chamber molded in. Plus the cam is different. I believe the blocks are identical except for the pistons. The relief in the pistons look identical but the Si's aren't as deep, giving a higher compression ratio. A pretty common "cheater part" for the ITC guys.

[Motor City Hamilton]

A pretty common "cheater part" for the ITC guys.
[/b]

What? <_<

The Si piston actually has a larger area dished out of the top of it, which would create less compression when used with the CVCC head.

[R2 Racing]

Really? Hmmm, maybe I have it backwards. It&#39;s been too long. Either way, the pistons are different. I got that much right. :P

[anrkii]

the interchangeable parts between the spec lines are the block, crank, and rods.

pistons, head, cam, intake not so much.

[Tkczecheredflag]

Blake&#39;s right. The heads are entirely different since they have the CVCC chamber molded in. Plus the cam is different. I believe the blocks are identical except for the pistons. The relief in the pistons look identical but the Si&#39;s aren&#39;t as deep, giving a higher compression ratio. A pretty common "cheater part" for the ITC guys.
[/b]

The cheater piston for "B" (si) and "C" (dx) is the 1300 HF piston. The dish/dome is shallower creating more compression, but the other advantage would be there is only 1 oil ring and 1 compression ring (vs 2 compression rings) offering less friction and drag - and yes the 1300&#39;s fit. Grassroots Motorsports did a Dx Civic project car several years ago (a series of articles back 1992 or 1993), were they did several "mods" and offered this piston as a "cheap" higher compression piston outlining all the pros and some of the cons. I saved the article if you want to referrence it - I just looked at the GRM archives to see if I could post it but did not find it. Aside from the fact that you would be cheating, the other downside would be a cracked compression ring - If you crack the only ring that provides compression, well, so much for the flat dome. A quick run through "tech" with any type of "volumeter" (sp) would reveal the higher compression - "busted."

[Motor City Hamilton]

The 1300 piston idea is great for a tuner kid on the streets as "cheap" compression gain. But for the ITC racer, if you want to deck the block/head, there is already very little room to deck and still be within the compression ratio. Plus, add in the aftermarket 0.040 over pistons and the ITC motor will kick the 1300 pistons butt.

The real gain in the ITC motor is in the head. Good, smooth, careful port matching, the right header, good new tall cam lobes and good lift from new stock rockers. We measured my old rockers and couldn&#39;t believe the difference in wear between them. If you&#39;re going to spend money and time on your motor, start with the head.

[Tkczecheredflag]

The 1300 piston idea is great for a tuner kid on the streets as "cheap" compression gain. But for the ITC racer, if you want to deck the block/head, there is already very little room to deck and still be within the compression ratio. Plus, add in the aftermarket 0.040 over pistons and the ITC motor will kick the 1300 pistons butt.

The real gain in the ITC motor is in the head. Good, smooth, careful port matching, the right header, good new tall cam lobes and good lift from new stock rockers. We measured my old rockers and couldn&#39;t believe the difference in wear between them. If you&#39;re going to spend money and time on your motor, start with the head.
[/b]

Fully agree on all points.
In addditon the 1300 pistons are illegal.