Non interference engine!

Kerazee · 23 Mar 2006 at 20:00

Dogbreath said:
The 3SGTE is allegedly, but I know of 3SGE's that have had bent valves so I don't think they are. That would make sense as the 3SGTE has a lower compression.

It's not exactly simple to make a non-interference 16v engine with decent performance. The required combination of high valve lifts, longer duration and high compression are at odds with the requirement for plenty of valve clearance.

Both the 3S-GE and the 3S-GTE are "non-interference" but are both more commonly "semi-interference" due to the build up of carbon.

geiger · 23 Mar 2006 at 20:24

So the valves stick because of the carbon..

Glaucus · 23 Mar 2006 at 20:26

Thats what I love about pushrod design engines. Like the chinqo no fan belt no problem.. In fact the only belt is water pump/aleternator.

Lashout_UK · 23 Mar 2006 at 20:31

Same. Belt on mine drives the alternator. Thassit!

Hell, if it goes, battery (provided it's good) still has enough juice to keep you trundlin' for a while!

Except mine's not a "pushroad" engine

Glaucus · 23 Mar 2006 at 20:34

no evidence..

de de dum dee dee
*scuttles off*

Dogbreath · 23 Mar 2006 at 20:53

geiger said:
So the valves stick because of the carbon..

No, the valves hit the pistons because carbon build up reduces the clearance to less than zero.

Lopéz · 23 Mar 2006 at 22:23

My Mum's 94 Civic 1.5 did 120,000 miles on the original cambelt (supposed to be changed at 60,000) and it snapped. Not a single bent valve!

Dogbreath · 23 Mar 2006 at 22:44

Lopéz said:
My Mum's 94 Civic 1.5 did 120,000 miles on the original cambelt (supposed to be changed at 60,000) and it snapped. Not a single bent valve!

A friends VTi of around the same age had the valve head drop off, which mashed the piston and combustion chamber, then the remains managed to go back up the inlet runner to the plenum, then down the adjacent inlet runner and totaly borked the next cylinder as well. Was only at ~4000RPM at the time.

ajgoodfellow · 23 Mar 2006 at 22:48

The cambelt on my Dad's Xantia 1.8 16V snapped when we were slowing down for a roundabout - can't have been more than 2,000rpm and it destroyed the engine! Made a hell of a bang too

Shoei · 23 Mar 2006 at 23:09

Third Opinion said:
Why didn't they just use an engine with a cam chain?

Because the cam chain tensioner can fail which is just as bad. Chain will stretch over time and needs to be kept at right tension, if not chain gets all slack and skips a few teeth.
Honda VTR1000 bikes have had problems with cam chain tensioner's failing and if your lucky it only take out a couple of valves when the chain skips.
Now gear driven cams, thats a different fish of kettles. No having to worry about belts or chains at all, just the gears make a lot of noise.

Robb