Identifying a 1987 CRX HF engine, help please
 

Hey I just bought a 1987 hf for $250! Great body, but it, unfortunately does not run, but I'm wondering how to accurately identify the HF engine in the 87. They said it was the original engine, but I want to be sure. Anything you can provide will be greatly appreciated. Thanks--
Andrew

I just bought an 87 HF 2 weeks ago- click on "Stingray" on the left to see pics of the engine bay.

There should be an engine ID tag on the left side of the engine bay. The engine block ID is located along the back side of the engine block along where the block bolts to the trans- just below where the two heater hoses attach to the thermostat housing.

The best indicators of an HF engine are the gray aluminum air cleaner housing and the black plastic valve cover with a threaded oil filler cap. The hf cylinder head is the 8 valve type. The 12 valve head is the non-hf type. The 8 valve head has roller tipped rocker arms and weak valve springs to reduce the power needed to open the valves- that's why the red line is only 5,500 rpm for the hf motor. The HF also features only one compression ring per piston in order to reduce friction losses.

These engines/carbs are pretty simple to work on- the catch is that if one of the 40+ vacuum hoses is leaking, it can cause problems with the idle etc.

The only real weakness of the CVCC engine is its tendency to crush the head gasket between cylinders 2 and 3 if you ever allow it to overheat. A head gaket is only about $25 but it is a good idea to have the head checked out by a machine shop to make sure it is not slighly warped- if it is it can be milled flat. If you put a warped head back on, you will just blow the head gasket again shortly.

If you are really lucky, it may just need a fuel pump or starter.

You rock
 

Hey thanks Eric! I actually saw your pics and wanted to respond to them and ask you directly but couldn't figure out how. I'm glad you found me anyway. My engine looks exactly like yours so I am encouraged. Is the HF the only one that used the black plastic valve cover, really (and could one use a HF valve cover on a DX, say)?
I do have a couple more questions I hope you might be able to help me with. Are the HF engines the only ones with 8 valves? This seems like it would be an easy way to tell one from another, but I can't tell from the technical specs that I have come across if the DX has 8 too. Also, the id badge between the trans and the block; what is the HF identifier #, or what should it be?
Anyway, if you know the answer to either of these I'd appreciate you passing it along. Unfortunately, getting mine running is going to be a bit of an effort. The previous owner ran it out of oil and the timing belt is in pieces. I knew this going in and am actually looking forward to rebuilding it. Rebuilding kits look available and (relatively) inexpensive, and re-boring the block and resurfacing the head shouldn't be much more then $150! Thanks again for the response and the pics--
Andrew

Yes- the HF is the only one that used the black plastic valve cover- but you can put the HF plastic valve cover on a non HF head and vice versa.

The 8 valve head was also used on the 1.3 liter engine(which came in the Civic Standard), but the 1.3 has regular (high tension) valve springs and normal non roller rocker arms. The Civic DX had the 12 valve 1.5 liter engine.

The best way to tell that you have an HF head is 8 main valves (a total of 12 valves since the miniature auxiliary intake valves on the exhaust side of the head aren't counted) and the roller tipped rocker arms. You may also notice how easy the valves can be opened by hand when you push on them.

There is no special engine code for the HF engine (it is likely a D15a2 as is the non HF 1.5 liter for that year). The block and heads and transmissions are interchangeable with all 84-87 cvcc carbed 1.3 and 1.5 liter engines.
The HF has a slightly higher compression- which may be due to flat top pistons (the pistons in my original 1.5 liter civic dx engine were slightly dished, but the 10:1 compression ratio 1.3 liter pistons were flat topped). I haven't ever seen my 1.5 HF pistons, so I can't verify this.

After rebuilding the 1.3, I can give you a few pointers.

1. Honda bearings are meant to be precisely matched to the individual crank journals and block tolerances. There will be code letters and numbers stamped onto the crank and the block that correspond to exact measurements of each. The aftermarket bearings that are sold are sort of a middle road of these measurements.

See:

https://www.team-integra.net/sections...?ArticleID=405

and

www.hondaautomotiveparts.com


After I put mine in and used the plastigauge, I found that a couple of them had too much clearance so I had to order a few main bearing shells from Honda that were a little tighter- at a cost of $16 per journal!! I just wished that I would have reused my old bearings- which were in pretty good shape. These bottom ends seldom go bad so maybe you will get lucky and all of the bearings might still be OK (depending on how long they ran it without oil).

2. Rings- I bought a set of Hastings chrome rings for my 1.3. The 1.3 engine (like the HF) also has only 1 compression ring. The original 1.3 compression ring is cut so that it overlaps. The aftermarket rings were straight cut- so I am losing a bit of compression leaking through that tiny gap. I wish I would have searched a little more and gotten the piston rings with overlap.

A full gasket set for the 1.3 was about $120, The machine shop work was about $130 (valves ground, head milled, and block milled -the block deck was 3 thousandths warped- right at the service limit), $100 for all the bearings, and about $50 for the piston rings. Roughly $100 for timing belt, water pump and tensioner. I guess it was about $500 for the rebuild.

Since your timing belt had broken- you probably will need to replace some bent valves...