HC ?

[rogerch]

I feel dumb asking this question, but how do you know if you have a high compression engine, engine number, series, model, or compression test, 88 Stevens Turbo ? I ask because this seems to make a difference to timing the belt and I'm about to change mine.

[andydclements]

The head has "HC" stamped in it where the number is stamped in (not the casting part number).

[Mike6]

We have the same car. I understand it to be LC but in any case the timing is 10 degrees btdc

[andydclements]

I'd expect a Stevens Esprit to be HC as the last of the G cars were HC, it could be said as a dry-run for the new design of engine.

[910Esprit]

From the factory, HC engine was red LC was black. LC oil filler cap next to bulkhead. HC filler cap near rear of engine. HC stamped on head near timing pulleys. HC has a small bore pipe water outlet from head near bulkhead. LC has large.

The difference to the timing belt is the tooth profile. HC has round teeth. LC has square teeth.

As mentioned, yours is HC unless a retro fit hs been performed

[stevem]

Hi Roger

Yours will be HC same as mine, cambelt's are available at Elan Factory in Melbourne, $65 plus GST. ( gates belt ) They also have the tenisoner bearing if you are changing that, I didn't bother as it was changed previously less than 6000 miles ago and was in good order.

have fun

Edited March 17, 2011 by stevem

[rogerch]

Thanks guys, Having had the car for 3 years, I tend to think this is something I should have known. But when ordering the belt it came up as the one for HC, and I had no reason to believe mine was. I would have expected something like HC within the engine number sequence, but apparently not. It's all OK the right one is on order, just potentially confusing.

[slewthy]

So....firstly, I havnt gone out to check my engine, but,

I have a square toothed cam belt.

Black cam covers, flat profile.

BUT the oil filler is at the rear of the engine.

My car is a 1986 N/A. It seems that its almost a mix of things from the engine point of view.

[andydclements]

All the bits you've mentioned are, as Steve pointed out, possible to change. It would seem odd to move from HTD2 to square-tooth, but sensible to move from saddle covers to flat (along with carriers) would be sensible so I'd say it's LC.

The absence of any "HC" stamp is all you can really look for, as the LC engine was the only one at the time there were no LC stamps on original engines. I'm not sure if the factory started stamping "LC" on replacement heads made after the introduction of the HC engines.

[MrDangerUS]

I think that HC designation is non-relevant for turbo engines. Only N/A can be trully High Compression with 10.9:1 CR. However, all Turbos have 8.0:1 CR. In 1986 Lotus started using NiCaSil sleeves and forged Mahle pistons, first on their N/A HC(!) 910 engines and thereafter on all Esprit engines.

By this virtue ALL engines from 1986 on, are "HC".

!988 cars with Bosch CIS are the transitional year "hybrides" and therefore pretty unique. Mechanically they have a lot in common with Gugiaro 86/87 HC-s.

How about starting a "88-er's Thread" specific to this confusing Lotus concoction?

Edited March 18, 2011 by MrDangerUS

[andydclements]

Earlier Turbo engines were below 8.0:1 as they were 7.5:1 so the Nicasil linered ones were "HC", they were higher compression ratios than the iron linered ones. Which is exactly the same as for NA where compression ratios were raised and Nicasil liners used.