Show full size 924Board.org
Discussion Forum of 924.org
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 Technical FAQ924 FAQ (Technical)   Technical924 Technical Section   Jump to 924.org924.org   Jump to PCA 924 Registry924 Registry

engine swaps

 
Post new topic   Reply to topic    924Board.org Forum Index -> General Discussions
View previous topic :: View next topic  
Author Message
musicalannette  



Joined: 21 Feb 2012
Posts: 412
Location: UK

PostPosted: Sat Apr 14, 2018 1:02 am    Post subject: engine swaps Reply with quote

Hi, I just thought having seen one.

The 70's lotus engine looked a good swap for a standard 924. especially if it were right hand drive.

I wondered if it had been thought of or done before as the rest of the car would probably be up to spec apart from the radiator/cooling.

I know engines swaps are a lot of problem to get everything to fit but having seen one it looked the better proposition for the standard 924.

Rich,
_________________
good in the snow..but if you dont live in Germany....best find some very old tyres for a bit of fun the wet.
Back to top
View user's profile Send private message AIM Address Yahoo Messenger MSN Messenger
Cédric  



Joined: 27 Aug 2004
Posts: 1681
Location: Sweden

PostPosted: Sat Apr 14, 2018 2:23 am    Post subject: Reply with quote

Sounds like alot of work for what you get, a cool classic swap though, would look good in the engine bay. Wouldn't the later 2.2 912 be a better choice though? But it's still an engine with lots of potential hassle and expensive parts. I would put the money on the standard engine instead, light diy porting and cam and you are possible at 145-150hp with much less work.
_________________
´79 924
http://www.garaget.org/show.php?car=211
´80 924 Turbo
http://www.garaget.org/?car=160275
Back to top
View user's profile Send private message MSN Messenger
musicalannette  



Joined: 21 Feb 2012
Posts: 412
Location: UK

PostPosted: Sat Apr 14, 2018 5:24 am    Post subject: it would be Lots Of Trouble Usually Serious..... Reply with quote

erm I think those lotus made around 160hp on the road before tuning (16v), I am not sure but Cosworth may have made some superlight castings of that engine for racing/rallying out of aluminium and then tuned it for serious competition. They have very little torque and needed/liked to be revved....a lot!. They were very short stroke and second hand ones are around 500-1000 quid when you see them. maybe a slightly later engine would be more torquey I am not that up on them.

I think they were development knock on from/with GM from a 2.3 Vauxhall/Opel engine which went in the Chevette and some US models etc and the head bolts were the same as the lotus, however the lotus stroke is very very short....racing car short, I doubt you will get many heads that breath that well at that time (N/A) from a car out the factory door. They might even have the same bolt spacing as some US v8's....

It is the right era engine, the engine slopes the other way to the german units, ideal for r.h.d. and the rest of the car probably wouldn't need a mod apart from the radiator. It just seemed a good idea and thought someone must have done it before perhaps in the late 70's early 80's?

The power delivery would probably change the character of the car quite a bit.....but also its fuel consumption!!!

For a modern swap in a 944/924s the AUDI W8 is the obvious (low head scratching) choice.
_________________
good in the snow..but if you dont live in Germany....best find some very old tyres for a bit of fun the wet.
Back to top
View user's profile Send private message AIM Address Yahoo Messenger MSN Messenger
Carrera RSR  



Joined: 08 Jan 2010
Posts: 1534
Location: Somerset, UK

PostPosted: Sat Apr 14, 2018 5:34 am    Post subject: Reply with quote

Assume you mean an early Lotus twin cam? Not sure you'd get a good usable one for less than £5k would you? I found one that was for sale and now sold that hasn't run for 44yrs for £9k!!

I think there may be more suitable bangs for bucks
_________________
1980 931 - forged pistons, Piper cam, CGT turbo, 951 ducted FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife LSD
Now www.924board.org/viewtopic.php?t=34690
Then www.924board.org/viewtopic.php?t=31252
Back to top
View user's profile Send private message
musicalannette  



Joined: 21 Feb 2012
Posts: 412
Location: UK

PostPosted: Sat Apr 14, 2018 6:16 am    Post subject: Reply with quote

no no not a Cortina twin cam that was based on a kent from ford I think but the later slant engine that perhaps had a gm testbed origins.

It has close relations to this apparently, having never had 1 of each to try and offer up the head bolts as-well as a few small block v8's I dont know....

This one is the cosworth modded one.

https://www.google.co.uk/search?q=chevette+2.3+hsr&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi11rXF_7faAhUpKsAKHQMSCR8Q_AUICigB&biw=1097&bih=534#imgrc=Z0UW5nPD-vr5mM:&spf=1523648142802

These were Tony Rudd designed I think. But the 2.3 gm block probably allowed head development as a testbed at lotus before casting a block. I was told the 2.3 was based around half a v8 hence it "should" line up with one or other v8.

I am led to believe the racing/rallying engines were even lighter as they were special thin casings for weight, they doubke checked for voids in every casting and to check wall thickness, maybe this is "double the price" for a bit of head-work/cam/injector placing and super stiff valve springs and sodium exhaust valves..... I dont know.

https://www.ebay.co.uk/itm/907-lotus-twin-cam-engine-Jensen-Healey/282918183570?hash=item41df3ce292:g:pnkAAOSw-SBay5t4

https://www.ebay.co.uk/itm/JENSEN-HEALEY-ENGINE/142752682257?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D49130%26meid%3Dc635724a5b864ceaacca5a22d506093f%26pid%3D100005%26rk%3D5%26rkt%3D12%26sd%3D162963729078%26itm%3D142752682257&_trksid=p2047675.c100005.m1851

https://www.ebay.co.uk/itm/JENSEN-HEALEY-LOTUS-907-ENGINE-GEARBOX-WITH-CARBS-EX-MANIFOLD/162963729078?hash=item25f1652ab6:g:uCwAAOSw3q5aba8S

I think you can pressure-charge them, but in reality the original 924 head being of a heron design will respond to that far better as it cannot breathe well at atmosphere no matter what you do because of the valve faces inhibiting flow. iirc.(why Porsche probably had to turbo the 924 in the end without it costing them a fortune on each engine and why jag and fiat had twin cam 2 valve heads to allow better inherent flow).

Dont for a minute think I am suggesting to fit something like that head to a v8! That's why Andrews sponsored the Chevette (for all the headaches)!
But Its just one of those things your told and unless you have several to hand you never know for sure.
Besides I think lotus made there own V8 in the end (as did Porsche).

But the Lotus engine used to develop around 160 hp I think but very very short stroke and thus without very very good breathing would not be able to shift any air. They were known as the torqueless wonder! I think they were able to tune quite a bit more out of it and its inherent max rpm would be much higher because of reduced piston velocity (top speed not gearbox limited as max rpm 7000+ back then if you leave the crank alone).

Anyway the aluminium lotus slant twin cam 900's was of the time and when I saw the engine I thought that MUST have been done by someone (probably with far more money than me) as I was around 6 when the 924 appeared. At the time it was probably the only 16v (apart from the dolly sprint) out there. It also address one of the 2 larger problems the 924 has here. LHD engine slant and should someone want to mod an engine at the time and hit a gear ratio problem with a lot of money be a logical choice (especialy if you mod the lotus engine it can go to silly rpm to match its power).
_________________
good in the snow..but if you dont live in Germany....best find some very old tyres for a bit of fun the wet.
Back to top
View user's profile Send private message AIM Address Yahoo Messenger MSN Messenger
nickthompson  



Joined: 26 Mar 2013
Posts: 849
Location: Central Georgia

PostPosted: Tue May 01, 2018 12:18 pm    Post subject: Reply with quote

Why would you want a Lotus engine? Those cars have a terrible reputation for reliability. I have a 2.3 Audi i5 in mine
Back to top
View user's profile Send private message Yahoo Messenger
Paul  



Joined: 02 Nov 2002
Posts: 9311
Location: Southeast Wisconsin

PostPosted: Wed May 02, 2018 8:16 am    Post subject: Reply with quote

LOTUS = Lots Of Trouble Usually Serious
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Back to top
View user's profile Send private message Send e-mail
Cédric  



Joined: 27 Aug 2004
Posts: 1681
Location: Sweden

PostPosted: Wed May 02, 2018 4:52 pm    Post subject: Reply with quote

nickthompson wrote:
Why would you want a Lotus engine? Those cars have a terrible reputation for reliability. I have a 2.3 Audi i5 in mine


So does audi, but they have made some really good engines in the past. Im not an expert on the later lotus engines but i never let assumptions get in front of knowledge.
_________________
´79 924
http://www.garaget.org/show.php?car=211
´80 924 Turbo
http://www.garaget.org/?car=160275
Back to top
View user's profile Send private message MSN Messenger
musicalannette  



Joined: 21 Feb 2012
Posts: 412
Location: UK

PostPosted: Tue May 08, 2018 9:28 pm    Post subject: Reply with quote

it as an engine of the time. The steering wheel is on the right side and the engine slopes the other way. It has a bit more power, breathes better than most 4 cylinders of the time develops anywhere between 140 and 220 hp and is far,far more revvy so doesn't have a problem with the gear ratios.
I thought it has been done already as it was a seventies engine. It is also lighter than the original unit. Really it is closer to a racing engine and someone at the time with A LOT of money before a 924s or turbo came along would probably have chosen it. Probably not it the US as they have v8's and the performance upgrades in mass production at a low price, but it is a "period" of the time logical choice. I think they have a bad reputation because if things are not measured and put together with a bit of care the right assembly procedures/materials(new parts sometimes dont get fitted where they need to as they can be costly) and/or cooling is slightly poor you have a recipe for a reputation. At a risk of repeating myself, I just thought it would have been done already at the time. If you look at seventies engines that were around it is the logical choice for a swap.
Maybe it was never done, maybe it has an nobody shows it. Once you put in a better engine then you have to think gearbox or gear ratios and/or possibly brakes. The lotus 900 series would have mean probably just an engine and spring/damper swap and something with the performance of the 944 range (plus if you drive on the "right" side of the road the engine slope along with the diff pinion and crownwheel isn't in a position where the Germans think it ought be). Honestly get a radio where the volume knob I on the left. Something to do with being right handed, the horse and cart and the whip no hitting pedestrians I believe. Clearly the continentals thought the minions weren't walking fast enough!!!!!!! What happens when you have a Napoleon Complex.....

I am sure the more modern engine swaps are sensible for efficiency and power and fuel economy and/or servicing ease or parts. Personally I liked the original engine, the exhaust and plugs were a pain, as was the distributor on fitment. For the least head scratching with modern vehicles I would have thought an audi W8 or a modern Jag v6 the best answer or a Honda s2000 if you want a 4 cylinder and it will fit ( if your thinking of servicing after fitment). All of those of course are normally aspirated. The other is a vw 1.4 tsi for European tax and fuel economy and around the same performance.
_________________
good in the snow..but if you dont live in Germany....best find some very old tyres for a bit of fun the wet.
Back to top
View user's profile Send private message AIM Address Yahoo Messenger MSN Messenger
musicalannette  



Joined: 21 Feb 2012
Posts: 412
Location: UK

PostPosted: Wed May 09, 2018 12:49 am    Post subject: Reply with quote

One thing that is worth pointing out is the layout of all the ancillaries that are attached to the Lotus 900 series. The starter, the dizzy, water pump etc..

All made to be accessed without a jack through the bonnet and to lower the engine. I think they sat and thought about the layout bit more and that is why they might have done the swap at the time?
_________________
good in the snow..but if you dont live in Germany....best find some very old tyres for a bit of fun the wet.
Back to top
View user's profile Send private message AIM Address Yahoo Messenger MSN Messenger
Display posts from previous:   
Post new topic   Reply to topic    924Board.org Forum Index -> General Discussions All times are GMT + 11 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group