removing/replacing heads: engine removal?

mik_str · Post by **mik_str** » Fri Apr 27, 2007 4:38 pm

Just wondering if removing/replacing the cylinder heads requires the engine to be pulled out of the frame or can this be accomplished by other means?

Also, I got my bike dynoed again yesterday and, much to my chagrin, actually lost hp and torque since my last session (about 15,000 miles ago; peaks are now 102.1 hp and 65.6 ft-lbs vs 105.5 and 68.8, same dyno and operator, yesterday was cooler by about 10C or @ 20F). Does this seem normal to you guys or have mods led me astray? *sigh* The new curves mimick the old but are slightly below. The dyno operator (experienced tuner, was told yesterday these guys prepare the engines for Honda Canada's racing effort) stated that the loss is due to the engine getting "tired" (doesn't seal as well, but then it does have 55,000 miles on it, although it still purrs like a kitten). Assuming this is the problem, would new rings and a honing bring me back up to speed? If so, can this be done without removing the engine from the frame? I would assume it can be done by dropping the sump and removing the piston and rod assemblies from underneath.....

Sorry for all the questions but I know you folks have lots of experience and I am still learning (plus I don't have my own garage so I can't do this stuff myself; joys of apartment living).

Thanks in advance

cheers

Stratman · Post by **Stratman** » Fri Apr 27, 2007 5:08 pm

Whilst I can't say whether or not you could do all that stuff with the engine in, if it wasn't burning oil or otherwise playing up I don't think I'd go to all that trouble to find 2/3 bhp which you didn't know you hadn't got till you went on the dyno!

Solution: Avoid the dyno!

The loss could be due to any number of smaller things - maybe some Redex or similar would remove some gummy deposits etc and clean the internals up a bit?

mik_str · Post by **mik_str** » Fri Apr 27, 2007 5:55 pm

I see pragmatism is alive and well, lol

Post by **sirch345** » Fri Apr 27, 2007 8:39 pm

Just a thought, were any of the mod's below carried out between the last two Dyno runs

modded airbox (`Bernie Morgan" mod, removal of ridge in lid and lip on stock air filter)
lenghtened intake runners

You're not that much down really, still quite impressive I would say

I think Stratman is right, it's not worth all that work and cost if it's not burning loads of oil

I presume the valve clearances are correct, in which case perhaps the Dyno was not having a good day, perhaps that was due for a re-calibration

alan · Post by **alan** » Fri Apr 27, 2007 10:36 pm

I say the loss is down to you modding the snorkel with your dremmel Mik and not anything to do with the lump!!!!!!!

Alan

mik_str · Post by **mik_str** » Fri Apr 27, 2007 11:18 pm

thanks for the input guys.

IN terms of airbox mods, all of the mods were already in place, with the exception of the snorkel being dremmeled. Mods performed in between the two sessions are the following:
- heat-wrapping of exhaust
- removal of PAIR system
- change of chain and sprockets (from 530 pitch to 520 pitch, from 16/43 to 15/43 gearing)
- installation of Flo-Commander
- addition of larger oil cooler
- re-packing of Microns

To Alan, do you really think the snorkel mod could have produced this? BTW, the snorkel is still in place, it is just opened up substantially compared to what it was before. I have a stock airbox lid I could install to check (mind you, that would also mean another $80 for dyno runs

) Guess I'll just have to try switching it next nice day (calling for rain here all weekend so the VTR will be staying in). BTW, what do you mean by "the lump"?

cheers

alan · Post by **alan** » Sat Apr 28, 2007 12:37 am

Hi Mik
i did the airbox mod,fitted a K&N had my pipework altered the vtr ran like sh1t.I put my airbox back to standard put a standard filter back in and guess what??? yeah its back to how it used be but only louder

no fluffy throttle,choking ,farting ,burping,splurting you get the idea

what i mean by lump lump= engine its a UK thing.

ps i dont think the snorkel mod has helped in anyway imho

i believe even the slightest change to the airbox,intake is enough to bugger the vtr up

mik_str · Post by **mik_str** » Sat Apr 28, 2007 12:59 am

gotcha! I will put the stock lid back on then (sure is nice to be able to do that, thank God for having a spare). Given what everyone says about the bike's sensitivity to intake mods, you are likely right.

I really appreciate the insight

cheers

P.S. Thanks for the lesson in dialect mate

Post by **sirch345** » Sat Apr 28, 2007 10:45 am

alan wrote:I say the loss is down to you modding the snorkel with your dremmel Mik and not anything to do with the lump!!!!!!!

Alan

Well remembered Alan