Adding Muscle - Now or never

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Oldtimer_Basis
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Adding Muscle - Now or never

Post by Oldtimer_Basis »

So, the Engine of my ´82 Excel just started spitting large Smokepuffs of Coolant through the Pipes. That most likely means: Head Gasket, which also means: Engine out. In other Words: Now is the perfect Time to talk about adding a few more Ponies to the Herd.
Suggestions?
What about the HC-Head? Is that just a simple Bolt-on with smaller Combustion Chambers, or does the HC-Engine have other Pistons?
If I also don´t like, what I will see in the Cylinders: What is the max. safe Overbore?
Gasket matching and Improving the Runners are Things I normally do, but I guess the stock Lotus-Heads are fine as they are already, right?
Can I get the Engine out without the Gearbox? Looks like there´s enough Space... and I´m lazy :wink:
How many lbs do the Cylinder-Head-Bolts get?
I´ll bolt off the Spark Plugs now and fumble an Endoscope into the Holes. Lets see where we´re at...

AndyC
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Re: Adding Muscle - Now or never

Post by AndyC »

Overboring of existing liners (if OEM) is a no-no, they're coated aluminium so boring would mean they're just ali and you can guess what the rings would do to them.
If they're aftermarket iron liners then you would need to find suitable pistons. I think there were lots of differences for the HC engine which only added 20 HP so so don't expect a lot just by that, in fact you could even find (I don't know) that an HC head but with nothing else could drop the power output.

Perhaps take the head and just a bit of gas-flowing.

tonypoll
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Re: Adding Muscle - Now or never

Post by tonypoll »

You may want to look here:
Sorry about the weird URL, but it gets you to the PPT that goes through a whole range of options on increasing your Lotus 900 series engine.
https://www.google.com/url?sa=t&rct=j&q ... _GhNSZta53

Pete Boole
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Re: Adding Muscle - Now or never

Post by Pete Boole »

I really depends on how much you want to spend! I'm building a supercharged 2.5 912 for my Elite but it's not cheap! I'd say the least that's worth doing is a good CNC-ported head (the original isn't that good), high compression pistons and a good exhaust manifold/system. With a pair of 104 cams that would be a noticeable difference.

Pete

Oldtimer_Basis
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Re: Adding Muscle - Now or never

Post by Oldtimer_Basis »

Okay, almost everything is off now. Can I leave the Tranny in the Car?

AndyC
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Re: Adding Muscle - Now or never

Post by AndyC »

You can but it's generally considered easier to take them both out together and put them back in together. That assumes that you have a decent access to the underside when reinstalling, if you don't then you will find it necessary to support the gearbox in a way that you can alter height and roll it That will help mate the two back together as you put the engine in.

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Lotus-e-Clan
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Re: Adding Muscle - Now or never

Post by Lotus-e-Clan »

Oldtimer_Basis wrote:
Sat Dec 11, 2021 00:10
Okay, almost everything is off now. Can I leave the Tranny in the Car?
Yes you can.

I replaced the clutch by removing only the engine. Others have on here too.

You have to jack the front of the tranny as high as possible within the tunnel to enable the sump to clear the front cross member. Remove the starter and you will see the flexiplate flywheel flex alarmingly when you press the clutch pedal to help part the bell-housing.

Fit an engine leveler to a long-reaach engine crane positioned at the front of the car and it comes out easy.
My job was simplified by having a 4 post lift to run the legs of the engine hoist under. ie you then don't have to jack the car or remove the front wheels.

Dump the very heavy flexiplate flywheel and fit a light steel one and you will not regret the improved revability and throttle response from low-down, nor the instant engine stop when you switch off!
Peter K

Oldtimer_Basis
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Re: Adding Muscle - Now or never

Post by Oldtimer_Basis »

Thanks Guys, that´s good News :D
Great Hint, E-Clan. Wasn´t thinking about that, because the Cars I work on usually have Automatics.
Okay, I´ll finish my Coffee and them I´m back under the Car again...

...almost forgot to tell: Cylinder 4 is the guilty one (probably the Head Gasket around Cyl.4). The Piston is wet from Engine Coolant. There also is Water mixed within the Oil and the Crankcase-Breather spat (is that the right past tense Form of "to spit"?) slimy Chunks of Water-Oil-Mix at the Air-Filter... yuk :?
So, the Leak isn´t just a single Spot between the Water-Jacket and the Cylinder...

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Lotus-e-Clan
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Re: Adding Muscle - Now or never

Post by Lotus-e-Clan »

Oldtimer_Basis wrote:
Sat Dec 11, 2021 16:26
Thanks Guys, that´s good News :D
Great Hint, E-Clan. Wasn´t thinking about that, because the Cars I work on usually have Automatics.
Okay, I´ll finish my Coffee and them I´m back under the Car again...

...almost forgot to tell: Cylinder 4 is the guilty one (probably the Head Gasket around Cyl.4). The Piston is wet from Engine Coolant. There also is Water mixed within the Oil and the Crankcase-Breather spat (is that the right past tense Form of "to spit"?) slimy Chunks of Water-Oil-Mix at the Air-Filter... yuk :?
So, the Leak isn´t just a single Spot between the Water-Jacket and the Cylinder...
Ah! number 4!

That's beacause No4 cooling is compromised when the heater is switched off. Mike Taylor from LotusBits had a number of engines with No 4 issues on his rally engines. He now modifies the cooling system to include a heater bypass hose to keep the coolant circulating around No 4 jacket when the heater is switched off. You probably didn't notice, but it is likely that No 4 head nuts were slightly loose compared to the others when you untightened them.
Peter K

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DavidOliver
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Re: Adding Muscle - Now or never

Post by DavidOliver »

On previous cars for extra muscle and as a start I have installed tubular exhaust manifolds, however not on Automatic gearbox cars where torque is more important than HP.
For my 85 LC I have not considered tubular manifold mainly due to cost and we already have an efficient air flowed head, I ask Forum members for their experience on this. There is also not a lot of room for tubular headers and the proximity of the fibreglass body concerns me.

Dave the cog.

Oldtimer_Basis
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Re: Adding Muscle - Now or never

Post by Oldtimer_Basis »

Okay, first Things first: The Cylinder Head Gasket was the Culprit. It was a normal Composite-Gasket and it disintegated more or less evenly, because the "Paper-Parts" of the Gasket didn´t seem to be overly "waterproof". On a lot of Areas it already disintegrated inside of the Sheetmetal around the Cylinders. So it was just a Coincidence that Cyl. #4 gave up first. I haven´t took a look at the Bearings, but I don´t expect to see anything unusual. So, the most simple Way back on the Road would be just to equipp a good Quality Gasket (maybe some Multi-Layer-coated-Copper or so) and bolt everything back together...
Sooo... I´m staring at the Block and the Head for a Couple of Days, now, waiting for the Voices in my Head to tell me what to do :twisted:
Frankly, I don´t really like that I´m seeing... free standing Cylinders? No Deck?!? Tiny Valves (but at least Plenty of Room for substantially bigger ones - but that would mean different Pistons), tiny Runners, tiny Exhaust Manifold (as Dave already mentioned), tiny Everything.

And I have no Idea what to do...

I could get rid of the Cylinders, install new ones for Pistons (with bigger Valve-Pockets), that are +4mm in Diameter bigger - which would mean 2.358 Liters of Displacement instead of the standard 2.1something (not exactly an impressive Enhancement), bigger Valves, widening the Runners and build a Header (or buy one, depending on the Price). I´ve played around bit with the Desktop-Dyno, and it says: roundabout 200 Horses.

On the other Hand: If I leave everything as is and just install a proper Header (one of the previous Owners already installed a good Exhaust, but left the exhaust Manifold untouched), the Dyno says: Almost 180 Horses @ 6.25 krpm...

Hm, now, that I´ve written that down, I´ll take Option 2.
If we´re being honest: Yes, the Excel is not the fastest Car in the World, but even with the 160 Stock-Horses it already has enough Performance to be great Fun. So, an additional 20 Horses are fine :D

AndyC
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Re: Adding Muscle - Now or never

Post by AndyC »

Head gasket, go with Goatze, not a copper laminate. Most Lotus specialists who cover these cars will have those readily available and they work well normally (providing there is the correct level of nip which you may wish to check).

One of my Excels has an ex-Gerald Kemp engine which was around 210HP with a bit of porting and the right manifold. It's now on a standard manifold but is still noticeably nippier than a non-tuned car (its starting point was the 180HP HC engine), so I'd seriously suggest light porting and gas-flowing with (as others have said) a decent manifold. I don't know of anybody that does a tubular manifold as a stand-alone, but they are available as part of an exhaust. That way it doers away with the flange that would become your next biggest restriction. Suspect you'll have to make the manifold if you want to leave the exhaust close to as-is.

Oldtimer_Basis
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Re: Adding Muscle - Now or never

Post by Oldtimer_Basis »

Yeah, with "doing nothing" I meant "doing nothing except Porting" :wink:
The Engine seems to react positively on better Exhaust-Flow - and there´s enough Meat on the Casting to do that. The Inlet-Side is okay already, a Bit of Cleaning should do. Gasket-Matching on the Inlet-Side isn´t neccessary - at least on this particular Engine. The Exhaust-Side has to be fit on the new Header, anyway.
I will still take a short look at who´s got what, but I think I´ll make a Header on my own. It´s a Pain in the AXX, but the good News is: It´s a 4-Cylinder, so I´ll only have to do it once :lol:
A Friend of mine has got an industrial Laser-Cutter (one of this Things, James-Bond-Villains use to cut Secret Agents into Pieces :shock: ), so I can start with a good Flange. The Rest is an endless Repitition of cutting, welding, fitting tiny bits of Tubes :cry: ...not really looking forward to that tind of Work.

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Re: Adding Muscle - Now or never

Post by richardw »

My understanding is, as noted above, that tubular headers tend to favour top end power and may slightly reduce mid range torque - but probably not noticeably. The cast iron manifold is a good all rounder and is also quieter as cast iron absorbs resonance well.

Cheers, Richard
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Oldtimer_Basis
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Re: Adding Muscle - Now or never

Post by Oldtimer_Basis »

Interesting Effect, Richard. Haven´t seen this Drop of Mid-rpm-Torque on other Engines, yet. But I have to admit, that I rarely work on 4-Valve-Engines. Usually Torque and HP increase over the whole rpm-Range.
Ah, and Dave: Heat-Wrap (this Rolls of Glassfibre-Cloth) always is a good Idea to lower the Risk of your Car turning into a Fondue.

...and I have to make some Compliments:
The Knowledge in this Forum is at Master-Level. Really impressive, especially when compared to other Car-Forums, where you normally have one or two Guys, that know a bit, and the whole Rest just talks and spreads false Information.

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