Honda Motorcycles - FireBlades.org banner

1 - 9 of 9 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Hi everyone, I'm new to the forum and am looking for some help. I've had my 1995 fireblade for about a year now and I've decided since it's winter now to do some maintenance including adjusting the valves. It looks like a bunch of parts were changed so I'm hoping some of the gurus here will be able to help confirm my thoughts. There are no timing marks on the crankshaft ignition trigger so I had to find TDC with a dial indicator, no problem there. The camshafts have Crane markings on them, am I right in assuming these are aftermarket or did Honda actually put Crane camshafts in from the factory? The sprocket markings are also very different from stock, the 'in' and 'ex' markings are pointing inwards when no 1 cyl lobes (furthest from the sprockets) are pointing outwards and slightly upwards. There are two arrows that are flush with the top of the cylinder head and pointed outwards when the cams are roughly in the right spot. Just to confirm, the intake and exhaust cams are in the right places. I suppose my next move is to figure out where maximum lift is and set it the right number of degrees relative to TDC?
 

·
President: Team Full Chat
Joined
·
7,357 Posts
That’s a lot going on there. So it seems like yes, you have aftermarket Crane Cams in your bike, which is cool. That clue can generally mean there are other “trick bits” strewn about the bike. Then that leads to a few more questions like what are they????

If there are no markings on the ignition rotor then that is aftermarket too.

Are the cam sprockets slotted, where they bolt to the cams? That means they were degreed (adjusted) to a specific number. So the arrow lines will basically be “a guesstimate” of “actual timing”. Even from the factory, they weren’t “spot on” with the top of the head.

Here’s a shot from my 93 build I did in 2013. Slotted can sprockets on stock OEM cams.

AB5740F2-56DB-486D-990A-9804A6E15E1E.jpeg
 

·
Registered
Joined
·
5 Posts
Discussion Starter #3
Thanks a lot for confirming that, I couldn't find any information on the Crane website for It does have slotted sprockets along with the camshafts but the rest of it is largely stock as far as I can tell. Full exhaust of some make, possibly a Hindle, but apart from that carbs are still stock, head isn't ported and the suspension is stock externally anyway. That's why I found the cams a bit weird, not exactly a first stage modification.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #4
Sorry, didn't fully read through that before I posted it. I meant to say I couldn't find any information about the cams on Crane's website. They have a section for Harley cams but that's it. Might need to call them up to get some info as well as just measuring the installed lift on the head.
 

·
President: Team Full Chat
Joined
·
7,357 Posts
Thanks a lot for confirming that, I couldn't find any information on the Crane website for It does have slotted sprockets along with the camshafts but the rest of it is largely stock as far as I can tell. Full exhaust of some make, possibly a Hindle, but apart from that carbs are still stock, head isn't ported and the suspension is stock externally anyway. That's why I found the cams a bit weird, not exactly a first stage modification.

I don’t think Crane has made cams for these old beauties for some time. Are the marks on the cams themselves? Or on the sprockets? It could be that just the sprockets were changed.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #6
Sorry for the late reply. I got into it a little bit more this weekend. The engine's on my bench and I took the head off to see what it looked like inside. 71mm bore which I think is stock for these. Maybe one of the lobes got chewed off from the originals and instead of buying OEM the guy bought aftermarket. It does have slotted sprockets and the cams themselves are Crane pieces. Do you happen to know a good starting point for the opening/closing events? I'm thinking I'm going to set them roughly similar to stock to begin with since there's no other supporting modifications and I can't find any info on the cams.
 

·
President: Team Full Chat
Joined
·
7,357 Posts
Sorry for the late reply. I got into it a little bit more this weekend. The engine's on my bench and I took the head off to see what it looked like inside. 71mm bore which I think is stock for these. Maybe one of the lobes got chewed off from the originals and instead of buying OEM the guy bought aftermarket. It does have slotted sprockets and the cams themselves are Crane pieces. Do you happen to know a good starting point for the opening/closing events? I'm thinking I'm going to set them roughly similar to stock to begin with since there's no other supporting modifications and I can't find any info on the cams.
I think I may have some numbers somewhere, it will take a bit of time to round them up.
 

·
Premium Member
Joined
·
294 Posts
I'm sure Ian will give you the good info, but (and my apologies for stating the blindingly obvious) just in case there is a mixup in part identitities, after you've assembled the engine you might want to rotate the engine by hand without sparkplugs in just to check the valves are clearing the pistons. I speak from personal (and expensive) experience. Standard there is only 1mm clearance at the closest they (usually inlet valves and pistons) get to each other, less if you've skimmed the head....and the conrods stretch by about 0.5mm at 12,000 rpm....
 

·
Registered
Joined
·
5 Posts
Discussion Starter #9
Much appreciated. Timing camshafts is new to me so I'm taking all the advice I can get. Because it's got aftermarket camshafts and I don't have any factory documentation I'm planning on claying the piston and turning it by hand to get an accurate measurement on my clearance. I didn't know the conrods stretched by that much. That's crazy to think about. What is the clearance you aim for on one of these engines? I thought I'd read .050" - .080" but that's quite a bit more than 1mm. Maybe I'm thinking of a different engine and need to mine the forum here a bit.
 
1 - 9 of 9 Posts
Top