19 replies to this topic

[Shooter63]

A bit of a general question really, with the price of base big bore engines getting near the 1K mark, will we see the small bore units making a come back. When you factor in the re-build costs after buying the base engine ( you've got to say a high percentage of engines will need re-building) you will be looking at the thick end of 2.5K. I know big bore units are great ie more power/torque but there is something about a decent 998, I converted my Mrs mini to 1293 a few years ago, love the torque etc but in away I miss that revvy little engine, it just seemed more fun, so much in fact that I've just picked up a 998 base unit for the princely sum of £10.00 with the idea of building it up to a 997 cooper type spec

Shooter

[sonscar]

I personally agree with you,but you do know that you now have pushed up the price of 998 engines.

[mab01uk]

998 is a great engine and has many advantages over a 1275....but tell everyone ! 

[timmy850]

I’ve been really happy with my 1098 engine and it didn’t break the bank

There’s also been a couple of supercharger kits recently developed for 998 engines:
Podifold (71hp with a stock Metro 998)
https://www.facebook...2712443434/?d=n

Specialist Components (115hp with a built engine)
https://www.facebook...9713665285/?d=n

[sledgehammer]

I like the 849 engine - nice and revvy 

 

I got one to build , but will need the triumph herald pistons apparently as it's +60 already -

 

(have been told this - but thought they were for the bigger engines not the 849)

 

anyone have details of possible alternative pistons & rods for the 849 +60 , as a lot of info on the net seems vague ?

 

I will have a look in the Wizzards bible as well , when funds allow - as piston prices seem a bit £££££ at the moment

Edited by sledgehammer, 18 September 2021 - 09:28 AM.

[Cooperman]

I have been thinking along the same lines.

I have a 998 block and a 1098 crankshaft on the shelf so I might get started on it in the new year. I can test it in my Grandson's 998 Mayfair/Cooper lookalike.

What I am thinking of doing is building an engine with around 1180 cc by fitting +100 thou pistons, which I believe are still available.

With a well-gas-flowed 12G940 head (35.6/29.5 valves with block pocketed), Evo001 cam, 10.3:1 CR, twin HS2, twin HS4's or one HIF44 (or HS6) carb(s), together with the other usual parts like an LCB, etc, it should give fantastic torque at least equal to a standard 1275 with a bit more power as well. 

No need for mega-revs and 6000 rpm would be effective max rpm, which matches the cam. Everything balanced for smoothness and a final drive ratio of maybe 3.44:1.

With that engine the car would be better than, say, a standard SPI or MPI in terms of overall performance, the engine would not cost a lot and it would pull well at low to mid-range.

[Spider]

It's a case of supply and demand really. There's high demand for 1275's and they have always been thinner on the ground than the small bore engines.

I feel there's still a lot of small bore stuff out there still to be driving prices up. I have a pile of them which are only junk to me, I'll more than likely be giving that stuff away. It is possible in time that they will become more valued, but I feel that's a while off yet.

One thing I think is easily over looked regarding overhaul costs is it's just about the same to do a small bore as it is a big bore and here, if one is looking to modify, I feel that's a greater variety of 1275 parts than small bore.

[Ethel]

Supply & demand? I'd think there were at least as many 1275's to be had out of Metros etc. They won't have been as knackered  as anything in Minis that limped on well past their natural age & if you found one it promised added oomph straight from scrapyard.

 

1275's are basically little A's that were stretched & squeezed in various spots on the draughtboard to find the extra cc's. 998's etc are less compromised in some fundamental places.

[Shooter63]

Since my initial post and thinking between watching the races at the Revival I remembered the laughs that we used to have blatting back from various runs or shows and managing to over take lorries and coaches on an M road or big multi laned A roads and even venturing out into the outside lane on the odd occasion if we could see a down hill section, I used to cane that little old bog standard 998 but it never let us down, as it was a late A+ job it had quite a long diff in it, when I think back all it really needed was a few more ft/lb, I think I might have wasted quite a few quid building a big bore lump for it plus it used to sip fuel, London to Brighton and back on a tank no problem, I'm off to start ordering parts.

Shooter

[whistler]

I have been thinking along the same lines.

I have a 998 block and a 1098 crankshaft on the shelf so I might get started on it in the new year. I can test it in my Grandson's 998 Mayfair/Cooper lookalike.

What I am thinking of doing is building an engine with around 1180 cc by fitting +100 thou pistons, which I believe are still available.

With a well-gas-flowed 12G940 head (35.6/29.5 valves with block pocketed), Evo001 cam, 10.3:1 CR, twin HS2, twin HS4's or one HIF44 (or HS6) carb(s), together with the other usual parts like an LCB, etc, it should give fantastic torque at least equal to a standard 1275 with a bit more power as well. 

No need for mega-revs and 6000 rpm would be effective max rpm, which matches the cam. Everything balanced for smoothness and a final drive ratio of maybe 3.44:1.

With that engine the car would be better than, say, a standard SPI or MPI in terms of overall performance, the engine would not cost a lot and it would pull well at low to mid-range.

This is what I've done with guidance from Keith Calver. +0.100" flat tops, Calver head, Piper BP255 camshaft, recurved electronic 59D, HIF38 (changing this to a HS6). Fully balanced with ultra ;light MS flywheel.. Special LCB from Maniflow (rubber cross U/J's) S/C box with 3.44. If I hadn't used S/Cuts then I would have fitted a 3.1 or 3.2 FD.

[Cooperman]

Yes, I think a 3.2 would work with standard ratios as the 1098 over-bored by 100 thou will give huge torque, especially with that cam.

 

The SCCR box is great for a 'cammy' engine and I use one in my 1275 'S' with the 286 cam, but I have to use a 3.9:1 FDR.

I once tried a 3.44:1 in an 'S' rally car with a BMC 544 rally cam (quite similar to the 286). The clutch soon gave up due to it having to be 'slipped' so much when pulling away on tests. I soon changed to a 3.9:1 which solved the problem.

 

I work on the basis that up to a 266/MG Metro cam the standard gearbox is about ideal with a 3.44 FDR or a 3.2 if the car is used mainly on smooth and level roads.

 

The 1098 engine, bored out a bit is the ideal solution for owners who can't afford to go to 1275 because the a base 1275 engine is now too expensive. It is easy to get 1275 power from a 1098 or slightly larger. One advantage with a 998 is that a really over-bored one does not need offset boring and can easily be made to give 75+ bhp with high torque as well. The big bonus is the torque curve really. I did once have an 850 which had a 1098 MG 1100 engine fitted. The only problem was the single-shoe drum brakes! In fact, it was my wife's car!

[Steam]

Small bore engines are fine, they go well and cruise well and when properly tuned and setup will give similar performance to a 1275.
BUT you cannot beat the smile factor of seriously putting the boot into a 1275.

[Icey]

This is the reason why when I wanted to build a turbo motor I used a 998. I’ve bought two 998s for a total of £200 over the last few years. In that time the 1275 I bought for £200 has quadrupled in value. No way I’m going to risk blowing that up!

[Shooter63]

Small bore engines are fine, they go well and cruise well and when properly tuned and setup will give similar performance to a 1275.
BUT you cannot beat the smile factor of seriously putting the boot into a 1275.

I totally agree, the project on the go at the moment is a 1380 16v job for my mk1, I had the block,crank and rods etc laying about, but if you had to buy a base unit then costs will be even more.
For the cost of the base unit you can no doubt pay for all the machining work ie re-bore crank grind etc and be half way though buying the new parts for the 998 plus those little engines run so sweet once set up properly

Shooter

[absx2]

I`ve just come back from a spin around in my 998 Cooper which is pretty much standard Cooper as in 12G295 head, twin su`s with airbox and an Rc40 with a free flow manifold.

The only thing other than a meticulous engine rebuild is a 266 cam and I have to say it`s got the edge over my Clubby with a slightly smoking MG Metro engine.

The little bugger just loves to rev and pulls like a train down low as well