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General Information => Troubleshooting => Topic started by: wolf_walker on November 28, 2009, 08:36:04 am
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Been a long time since I had a hyd head motor, and driving the mech head rabbit
the other day made me think of this again. Is it just me or are the
hyd head motors just, for lack of a better word, softer feeling?
Throttle response seems to be a little softer, free rev's a little
slower. Are the cam profiles weaker on the hyd motors or something?
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All I have been told is that the mech head has a few more hp. The auto adjusters must cost a few hp. ;D
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IIRC the hp difference is 1/2 hp and that's assuming the solid lifters are all correctly adjusted. If you actually feel a difference, then it is far more likely in the adjustment of the pump rather than the lifters.
Might be. In this case it's a lot of miles, dirty injector, smokey, shot mounts, generally run down 82 Rabbit putting around the farm
with a hanging by a thread clutch VS my just assembled new injector, meticulously timed 81 pickup that only just does smoke vaguely black under WOT.
Throttle response and
initial pull seem quicker on the Rabbit. Go figure.
Didn't one have a notably lower redline than the other? I don't have my Bentley handy.
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Nah, not that fresh. Just fresh gaskets when it went from jetta to pickup, new injectors, the usual.
It runs and drives well enough, the mech head rabbit just feels, different.
Might be a totally different experience out on the road, going to be awhile
before I can drive the rabbit and see.
It sort of stands to reason, on conventional v8's an equivalent mechanical
cam in a given motor compared to a hyd the mech one usually makes more power
as I recall, and has a higher redline. If it's adjusted correctly.
I haven't had a 1.6 with hyd lifters in many many years, this one just
feels different. Not bad, just different. If I had to try and put a finger
on it I'd swear it has less power below 2500rpm or so, but there
are so many variables these days. Fuel and all. FN trans in the rabbit
I think and an Axx form the jetta in the pickup. I had a 7A in my last couple
of VW's.
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No I think youre onto it. My 81 seemed to have more power than all the rest of the newer ones I have owned. I have never driven a turbo, but too me I am guessing the difference to feel like a turbo engine normall vs an intercooled one-all other things the same. The hydro heads pedal just seems squishy to me compared to a mech head being more solid...if that makes sence. And the biggest difference being in the low RPMs. The Mech heads just seem to have a crisp feel to the revs where the hydros aren't as linear to the pedal.
To me it makes sence anyway, hope it does to you guys.
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Yep, that's it.
FWIW, I asked my Father who's been driving these for decades about it
and he said much the same. No biggie, just an observation.
Worth it to me not to have to adjust the valves. :)