Choosing an engine
Discussion
I'm building a 4x4 buggy and reading up on engines. I'm a bit all over the place at the moment, there's a lot to take in! I'm trying to keep weight low, but if a bit more weight gives me a lot more power then I'm happy to make sacrifices on weight.
Same goes for price, I'd *like* to spend under £500 for engine and gearbox and all engine ancillaries (ECU etc), but I could go up to over a grand, even £1500 if the benefits warranted it.
So here come the questions:
I can't be the first person that's trying to figure out which engine to use, yet I haven't found a decent table that compares engines, their weight, power, etc. I've found the Westfield World website which does just this but it only have a few engines on there. But it's great because it also gives gearbox options that fit. Something like the Wesfield website but which has more engines would make things so much easier.
Why are inline four cylinder 2.0l engines so popular? Is that the sweet point of weight vs power or is it just availability and price?
I've looked at the Clio F4R engine, it is light, super cheap and does 197bhp straight out the box. Why is this engine not more popular in self built cars? It has more power out the box than the Duratec HE, is a heck of a lot cheaper. If I could find a rear wheel drive gearbox for it, I'd probably go straight for this engine, cheap and no hassle with having to upgrade it because the horsepower is already there.
The Duratec HE appears a lot, but there's extra costs for the bellhousing to mate it to a rear wheel drive gearbox. But isn't it using a Mazda bolt pattern, is there no RWD Mazda gearbox that it could bolt to?
The Duratec HE is tempting, I read that it's futureproof and highly popular. I like this, but it's weak compared to the Type-R of F4R and needs money to get it to 200bhp. I could live with 145bhp that it does (or whatever the figure is), just seems to be a dearer engine with less power. From what I've read, even the Type-R is cheaper because it already does 200bhp while the Duratec costs more by the time you upgrade it.
How much of a pain will I have with getting the ECU to work with these modern engines? I've heard that these modern ECUs are quite integrated with the original car and I'm wondering how much headache I will have getting the ECU side of things working. I probably won't be doing any tuning, or not much (to save money), so maybe an aftermarket ECU can be avoided.
What about engines bigger than 2.0 l? I've seen some Rover and Jag engines that appear popular but they are V engines so the weight jumps right up (I assume because of the V configuration). Are there any popular inline engines above 2.0l that are not V engines? Duratec 2.3l looks tempting but again, it's the price...
Why is the Type-R not more popular? Again I've seen complete cars on salvegaemarket for under a grand, and these engines do ~200bhp straight out the box. Also I haven't found any info on a RWD configuration for these Honda engines.
Same goes for price, I'd *like* to spend under £500 for engine and gearbox and all engine ancillaries (ECU etc), but I could go up to over a grand, even £1500 if the benefits warranted it.
So here come the questions:
I can't be the first person that's trying to figure out which engine to use, yet I haven't found a decent table that compares engines, their weight, power, etc. I've found the Westfield World website which does just this but it only have a few engines on there. But it's great because it also gives gearbox options that fit. Something like the Wesfield website but which has more engines would make things so much easier.
Why are inline four cylinder 2.0l engines so popular? Is that the sweet point of weight vs power or is it just availability and price?
I've looked at the Clio F4R engine, it is light, super cheap and does 197bhp straight out the box. Why is this engine not more popular in self built cars? It has more power out the box than the Duratec HE, is a heck of a lot cheaper. If I could find a rear wheel drive gearbox for it, I'd probably go straight for this engine, cheap and no hassle with having to upgrade it because the horsepower is already there.
The Duratec HE appears a lot, but there's extra costs for the bellhousing to mate it to a rear wheel drive gearbox. But isn't it using a Mazda bolt pattern, is there no RWD Mazda gearbox that it could bolt to?
The Duratec HE is tempting, I read that it's futureproof and highly popular. I like this, but it's weak compared to the Type-R of F4R and needs money to get it to 200bhp. I could live with 145bhp that it does (or whatever the figure is), just seems to be a dearer engine with less power. From what I've read, even the Type-R is cheaper because it already does 200bhp while the Duratec costs more by the time you upgrade it.
How much of a pain will I have with getting the ECU to work with these modern engines? I've heard that these modern ECUs are quite integrated with the original car and I'm wondering how much headache I will have getting the ECU side of things working. I probably won't be doing any tuning, or not much (to save money), so maybe an aftermarket ECU can be avoided.
What about engines bigger than 2.0 l? I've seen some Rover and Jag engines that appear popular but they are V engines so the weight jumps right up (I assume because of the V configuration). Are there any popular inline engines above 2.0l that are not V engines? Duratec 2.3l looks tempting but again, it's the price...
Why is the Type-R not more popular? Again I've seen complete cars on salvegaemarket for under a grand, and these engines do ~200bhp straight out the box. Also I haven't found any info on a RWD configuration for these Honda engines.
Hi again 
I4s are popular, as you say because they're a good trade off of weight/power, they are also small and will fit in most things easily. Things like your ford engines have superb parts availability, and lots of interchangability, hence are well known, cheap, and everything has been done before.
Much over 2L and you're looking at more cylinders. Modern V-engines, because they are mostly OHC, tend to be very wide and hence become difficult to fit (as me how I know
). They are used less often and hence rather harder to adapt to fit, needing custom engineering etc. Then you've got twice as many exhausts which can be a pretty major expense.
With most cars now being FWD, adapting to a RWD layout is a major consideration. Again there are plenty of parts to do this for the common engines. Things like your renault, less so.
ECU - well again, for the common engines, all of the tricks and foibles are known. Anything different, you're on your own, or looking to aftermarket ones.
Type R - if you're after an RWD honda "R" engine, everyone uses the F20 from the s2000, because it's already RWD. They're used pretty commonly now.
I spent, as I recall, around 3 months researching engines for my build. There's a lot to learn!
I4s are popular, as you say because they're a good trade off of weight/power, they are also small and will fit in most things easily. Things like your ford engines have superb parts availability, and lots of interchangability, hence are well known, cheap, and everything has been done before.
Much over 2L and you're looking at more cylinders. Modern V-engines, because they are mostly OHC, tend to be very wide and hence become difficult to fit (as me how I know
). They are used less often and hence rather harder to adapt to fit, needing custom engineering etc. Then you've got twice as many exhausts which can be a pretty major expense.With most cars now being FWD, adapting to a RWD layout is a major consideration. Again there are plenty of parts to do this for the common engines. Things like your renault, less so.
ECU - well again, for the common engines, all of the tricks and foibles are known. Anything different, you're on your own, or looking to aftermarket ones.
Type R - if you're after an RWD honda "R" engine, everyone uses the F20 from the s2000, because it's already RWD. They're used pretty commonly now.
I spent, as I recall, around 3 months researching engines for my build. There's a lot to learn!
Thanks Cruty, I'll look at that F20 motor if it has a RWD layout.
Just to clarify, I'm thinking of using a "stand alone" transfer box to get 4 wheel drive. I'm looking at a transfer box from a Suzuki SJ, so from the RWD gearbox, I can use an intermediate prop shaft to the transfer box (like Suzuki's do). I don't yet know if the SJ box will cope with double the factory torque going thru it, if not then it's another major expense to get a specialist transfer box like an Atlas. Or use a native 4x4 engine, or mate an engine to a Toyota gearbox/transferbox.
Just to clarify, I'm thinking of using a "stand alone" transfer box to get 4 wheel drive. I'm looking at a transfer box from a Suzuki SJ, so from the RWD gearbox, I can use an intermediate prop shaft to the transfer box (like Suzuki's do). I don't yet know if the SJ box will cope with double the factory torque going thru it, if not then it's another major expense to get a specialist transfer box like an Atlas. Or use a native 4x4 engine, or mate an engine to a Toyota gearbox/transferbox.
If you're going to build a 4x4, why not look at engine/gearbox/drive systems from a 4x4 donor and work from there?
It gets you round all the issues of which engine can be matched to which gearbox, etc.
The UK kit car scene has worked off Ford components for so long, and Ford are such a big part of the modding scene, it is a little difficult to see past them at times. Could you maybe use the layout from a TT, though by the sound of things you want to avoid a transverse engine, yes?
There's always Subaru ...
It gets you round all the issues of which engine can be matched to which gearbox, etc.
The UK kit car scene has worked off Ford components for so long, and Ford are such a big part of the modding scene, it is a little difficult to see past them at times. Could you maybe use the layout from a TT, though by the sound of things you want to avoid a transverse engine, yes?
There's always Subaru ...
A 4x4 donor would solve a lot of problems, I agree and that's what most people do. But one of my aims was to get an advantage by using an engine that gives better power to weight, by not just limiting my choice by looking at 4x4 donors.
I've found a solution though. The Suzuki SJ has a separate transfer box, it's not part of the main gearbox, so any rear wheel drive gearbox/engine combination can easily connect to it just by modifying the intermediate propshaft.
I'm looking at the Zetec 2.0 engine with MT75 gearbox because it's cheap and performance is relatively good. I've also found that the Clio RS F4R engine can mate with a Volvo 340 gearbox which is rear wheel drive, giving me 180 bhp for really cheap. An F4R with ECU and all ancillaries just went for £240 on eBay. That's a lot of BHP for the price right?
PS Been reading and the F4R often can't be used in kit cars because it's a tall engine, maybe explaining why it isn't more popular in kit cars.
I've found a solution though. The Suzuki SJ has a separate transfer box, it's not part of the main gearbox, so any rear wheel drive gearbox/engine combination can easily connect to it just by modifying the intermediate propshaft.
I'm looking at the Zetec 2.0 engine with MT75 gearbox because it's cheap and performance is relatively good. I've also found that the Clio RS F4R engine can mate with a Volvo 340 gearbox which is rear wheel drive, giving me 180 bhp for really cheap. An F4R with ECU and all ancillaries just went for £240 on eBay. That's a lot of BHP for the price right?
PS Been reading and the F4R often can't be used in kit cars because it's a tall engine, maybe explaining why it isn't more popular in kit cars.
Edited by rcx106 on Tuesday 10th March 22:31
vx220 said:
What about using a V6 Gran Vitara as a donor?
I've only vaguely looked at V6 engines, but they are much heavier, torque is much higher though. I'm trying to make this truck lightweight so it goes against my aims.CrutyRammers said:
Type R - if you're after an RWD honda "R" engine, everyone uses the F20 from the s2000, because it's already RWD. They're used pretty commonly now.
Taken a look at the F20 R-Type, that fits the bill, super powerful, but it's not cheap! £2k for the engine, plus still have to buy gearbox and ECU.The Zetec is still a possible candidate. Seeing as the F4R is so cheap I might still buy one and have a go at mating it to a RWD gearbox, and sell it on if it turns out to be too much work or not possible.
The SJ transfer box tends to have a very low ratio...
Depending on the type of off road you're looking to do this has it's pros and cons.
My old Samurai would do 40mph, flat out with a tail wind! Mug plugging it was a proper tool though. Shame I didn't do much mud plugging, and instead used it as my daily driver for 18 months...
Depending on the type of off road you're looking to do this has it's pros and cons.
My old Samurai would do 40mph, flat out with a tail wind! Mug plugging it was a proper tool though. Shame I didn't do much mud plugging, and instead used it as my daily driver for 18 months...
Sway said:
The SJ transfer box tends to have a very low ratio...
Yes I know, it makes the SJ box unique, it lowers the ratio by 1.4 or 1.6 (SJ413 and SJ410 respectively) and that's in the high ratio mode!!! This could be good because it will allow running bigger tyres, but also puts more strain on the drivetrain. It all needs to be calculated out which I will do once I've decided on an engine and tyre size.
rcx106 said:
Taken a look at the F20 R-Type, that fits the bill, super powerful, but it's not cheap! £2k for the engine, plus still have to buy gearbox and ECU.
The Zetec is still a possible candidate. Seeing as the F4R is so cheap I might still buy one and have a go at mating it to a RWD gearbox, and sell it on if it turns out to be too much work or not possible.
Yes they're not cheap - because they became desirable. But don't underestimate the work and expense involved in making a custom engine/gearbox combo. By the time I'd had an adaptor made up, and bought 2 clutches, and a custom flywheel, then had it all rebalanced, I was in for around 3K anyway...The Zetec is still a possible candidate. Seeing as the F4R is so cheap I might still buy one and have a go at mating it to a RWD gearbox, and sell it on if it turns out to be too much work or not possible.
CrutyRammers said:
But don't underestimate the work and expense involved in making a custom engine/gearbox combo.
I can believe that. As my planning goes on, more and more of my original ideas fall away because of restraints on budget, technology restraints, and most recently the MSA rules wiped out a couple more of my ideas. But I've done most of my planning now and there's still enough tricks on the planned buggy to make it worthwhile and hopefully it will be a good.Gassing Station | Kit Cars | Top of Page | What's New | My Stuff