what are the diff betweem vtec and non vtec

[yelizardking]

ok this dude was telling his engine is built exactly like a vtec but it isn't vtec because he "doesn't have a little tube going int the head" then. is this true? is there any truth in that? i doubt it. i asked him if he has vtec camshafts and he said he does. that it is just like a vtec but it's not b/c of the tube or pump., i forgot his exact words.

[ChrisCantSkate]

well, he could have disabled the vtec soilinoid, but basicaly the difference between vtec and non vtec in a nutshell is vtec allows 2 different cam grinds and non vtec donst.

[yelizardking]

can you have vtec cams in a non vtec engine?

[2ndGenTeg]

no

[Mushroom]

Originally posted by yelizardking
can you have vtec cams in a non vtec engine?

As I understand it: 2 parts to vtec - different cams, with 2 sets of lobes to drive the valves differently depending how they're positioned, and control hardware (e.g. solenoid + electronics), which pop the cams between the 2 positions. The whole point to the performance-oriented vtec is that when you hit high revs valves run differently.

The "little tube" might be something in the valve that allows the engine to run with a valve closed (???) - I know the economy vtec (e.g. insight, maybe the HX) closes valves when you don't need them.

[2ndGenTeg]

The heads are completely different. VTEC cams will simply not go into a non VTEC head.

A VTEC head has much different rocker assemblies. There are two different sets of rocker assemblies: VTEC and non VTEC. Before VTEC is engaged, the rockers for the VTEC lobe are unlocked, so the valves just utilize the non VTEC lobe. As soon as VTEC enages, the rockers lock, and the valves use the more aggressive VTEC lobe.

Non VTEC engines only have the single set of rocker assemblies. In addition, the space between camshaft lobes is larger, since there's only one grind.

Bottom line: you can't have VTEC or VTEC cams with a non VTEC head.

[yelizardking]

so that dude is out of whak or is he right?

[yelizardking]

by right i mean can he do that or is there any way of doing that, you guy's get me? or am i going all whacked out?

[Mushroom]

As you tell the story, I think the dude's whack. Of course, other manufacturers use variable valve timing in their engines, so maybe he has a toyota or something that uses a vtec-like arrangement.

[yelizardking]

he has a 91 integra. when he was talking about engine this is "you got the gs and the vtec wich is the best one" then i told him the type r is the best but then he insisted that the gsr is better. i let him take that argument for the sheer fact that you cannot argue with fools.

[2ndGenTeg]

B18A/B (No VTEC): RS, LS, GS, SE
B18C (VTEC): GSR
B18C5 (VTEC): ITR

Now, for 10 points, who can tell me the differences in the B18C and the B18C5 longblocks?

[yelizardking]

the b18c is jdm and the c5 isn't.

[2ndGenTeg]

Nope. Read the above again. The B18C is the Integra GSR motor. Of course the GSR was available in the United States. And of course the Type R was available in Japan.

Both motors were available in both Japan and the US. The only difference (in the longblock) between the JDM and USDM versions of the motors was the compression ratios. JDM engines usually run a higher compression ratio because they generally run higher octane gas than we run here.

[yelizardking]

well that was obious everyone knows what the compression ratio is higher in jdm motors. but there are some dumbass guy's at chap shops that when you ask for jdm they say it's the same exact thing when they obiosly aren't