Cam Gears?

[Techfizzle]

I read somewhere that the tech IV engine had hyphoid gears and alot of time the would fail and the motor would lock up, is this true?

[Tonglebeak]

Plastic teeth on the timing sprockets I believe is what you're thinking of, someone else should chime in on this...

[85_Ciera_Rebuild]

I read somewhere that the tech IV engine...

I know nothing....but it appears Tech IV is not...but, look for yourself.


Interference Engines (http://cylinderheadsupply.supersites.ca/interferenceengines/)

The AERA Technical Committee would like to offer the following information on engines that present the possibility of interference between pistons and valves. The interference or contact may bend valve(s) when timing between the camshaft and crankshaft is interrupted. This is generally the result of a timing belt or chain breaking or slipping.

I wonder if someone could save this URL somewhere?

Note - It appears this list goes up to 1998 era...no later.

The following list are engines that AERA is currently aware of that have exhibited interference. There may be other engines that are not listed below that have the possibility of piston to valve contact. If the engine you are working on is not listed, do not assume that it is a freewheeling design. It is suggested to add to this listing as additional information is obtained.

[87Cutlass Ciera]

As far as I know, if the teeth wear out, you will get valve/piston kiss. My engine has 207000km's on it and there is a little bit of play between the teeth (which is why Tech IV's are so noisy) If you replace them, replace them with a metal on metal instead of nylon, I believe the Metal ones should give you better life.

[85_Ciera_Rebuild]

....little bit of play between the teeth (which is why Tech IV's are so noisy)

Noise from Gears or from Piston/Valve slap?

[87Cutlass Ciera]

Noise from Gears or from Piston/Valve slap?

Noise from gears. ooohhh I see what I said that was miss-leading. If the teeth wear down to the point that they break or that one gear can slip a tooth or something like this, it could result in Valve/Piston kiss if it got really bad. But a lot of them are noisy just because of a little bit of play between the teeth, not enough for the gears to slip, just enough to make noise when idling.

[jofier90]

Hi
I have a Cutlass Ciera LS 1984
The engine is the original and I want change it
Who is the best engine for this car?

Thanks

[LordDurock]

Hi
I have a Cutlass Ciera LS 1984
The engine is the original and I want change it
Who is the best engine for this car?

Thanks

i got a tech IV 2.5 for sale.

[85_Ciera_Rebuild]

Hi
I have a Cutlass Ciera LS 1984
The engine is the original and I want change it

Yes...which engine? What state you live in...Mexico I'll assume.

[glasspilot]

I read somewhere that the tech IV engine had hyphoid gears and alot of time the would fail and the motor would lock up, is this true?

OK guys, the Tech IV is not an interference engine. Back in the early '90's my original cam gear disintegrated and my engine stopped. No valve/piston interference. The engine did not lock up; it just stopped. The dealer replaced the original composite gear with a steel one. Noisier but reliable. (The composite gear was an attempt to quiet it down, kinda worked but the gear wouldn't last; mine blew up at 60,000 miles).

Interference engines are usually newer designs; overhead cams and multivalve heads and such. The Tech IV was an old fashioned push rod design (but still reliable and efficient in it's last forms).

I'm still driving it! Original owner, 20 + years, 160,000 miles!:cheers: