The Lotus Grand Tourers

I believe there should be some plastic, snap-on shoes on the feet of the BT-33-86J gauge. Without them, the calibration would be off. I know nothing about the KM4088AR. Both look like they have enough miles on them that they should be re-calibrated... shoes or no shoes.

Regards,
Tim Engel

Lotus valve shims for Twin Cam and 9XX engines are the same. And both are interchangeable with shims for the Triumph TR7 and older Jaguar XK 6-cylinder engines (Moss Motors, Victoria British, The Roadster Factory... etc), Saab 99 2-valve, Cosworth, Coventry-Climax (vintage racing suppliers) and the ...

15" x 7" . . . . Rim Size, Inch +23.3. . . . . . Offset 60mm. . . . . . Center Bore 5 x 4 1/4" . . . Bolt Circle, Inch 5 x 108mm . . Bolt Circle, Metric When you ask about Offset, be aware that some websites or retailers will reply with ET. Offset and ET are NOT the same thing. Measured on the same ...

The impeller used in the 907 pumps had very few, short vanes. That may (??) also apply to the 912LC. The 910 Turbo and 912HC pumps use an impeller that has more, much longer vanes. That, plus a deeper scroll housing portion of the pump housing means the later pumps can move a lot more coolant for be...

Follow this link to a PDF file on how to rebuild the water pump: https://tinyurl.com/565eaeay Early seals were over-molded with black rubber, while modern seals are stainless steel. They're easy to tell apart at a glance. Presuming any modern rebuild kit will include the stainless steel seal, you wi...

Here are a couple of updates on that same theme:

Balancing Dellorto - 'The Lotus Grand Tourers' - by Tim Engel.pdf
https://tinyurl.com/bdhmukjy

Balancing Dellorto & Weber Carbs - Procedure - Tim Engel.pdf
https://tinyurl.com/5cm35fdx

Regards,
Tim

Just my opinion, but I avoid using silicone sealants on engines, When you tighten the joint, and a little silicone oozes out, you can easily wipe off the excess. No big deal. But whatever you see oozing out on the outside of the joint, you can bet there's a similar amount on the inside. And while th...

Go Here: https://tinyurl.com/mryxsnhk to download a copy of '9XX Engine Rebuild Data, 4-Cyl - Master.xlsx' Note that it's an Microsoft Excel.xlsx 'Workbook' containing multiple 'Worksheets'. Click on the tabs across the bottom of the Workbook to open any Worksheet. "Engine Rebuild Data" is my notebo...

Go here: https://tinyurl.com/45kwkm4y This page is from the 93-97 Service Notes simply because I had it handy. The flatness info applies to all 9XX 4-Cylinder heads. "IF" you have the head milled to flatten it, make sure the machinist knows the bottom & top of the head must be parallel. The cranksha...

I use gaskets for all 9XX 4-cyl applications, regardless of what the Lotus manual says. I've experienced leaks with pumps that are sealed with an anaerobic sealant only, so rather than mess with it anymore, I just put a standard gasket in the joint and seal it with Hylomar AV. It seals well. I'm an ...

Nice article overall, but the author clearly wasn't an expert on the Excel. For instance, he wrote, "At the same time, the rear suspension was modified to incorporate the Esprit’s top link and lower wishbone layout in place of the Elite’s Chapman strut." Wrong Elite. The Type 14 2-seater had Chapman...

The 'pin' does have to be removed before the piston can be withdrawn. However, it's more than just a pin you can abuse, it's actually a small valve that should be treated well. The piston hits it and tips it, causing it to vent... the 'Tip-it' valve.

Regards,
Tim Engel

I've cleaned-up those six JPEGs and combined them into one 1.04 meg 6-page PDF. Unfortunately, the original text resolution was a little fuzzy, and it's no better in the PDF. If you want a copy, you can download one here: https://tinyurl.com/4enks6b7 That's my GoogleDrive accounnt, and I have limite...

Back in the day, Lotus recommended 20W-50 viscosity oil for the 900-Series engines. You can play with the 20W part (cold viscosity), but keep the '50' part (hot viscosity) at 50 or higher... a 10W-60 would be great. And select an oil with a high ZDDP content. Or, more to the point... The P in ZDDP i...

It's important to know the final film thickness of the sealant you use. For Loctite 515 & 518, it's 0.0005" / 0.0127mm. What is the film thickness for the "high temperature sealant that you can get from Halfords"? If you don't know, I'd advise against using it. For the optimum service life, shim to ...