What engine to use in a competition truck

[Steve Hiatt]

The cast iron small block Chevy is not that heavy with ali heads, inlet and water pump. I know it's difficult to get exact comparisons because everyone seems top offer different weights, but if I remember my figures an ali headed Chevy will be about 30kg heavier than a dressed Rover. But the old cast heads, inlets and water pumps are heavy.

With the Lexus, my understanding is that they are easier to get to run than when our Matlock friend first fitted one. As I understand it the comment was 'so where do these 40 wires go?'

[Rolly]

Just to be silly, a "Merlin Mountain". 454 Chev bored and stroked out to 11 litres, oh baby!

[Turbocharger]

Lots of differing but very valid ideas on here. I think it depends on the type of competition you're doing. As FF put in another thread, "run the same as what the locals do"... ?

Otherwise, lead the pack if you're looking to innovate. If you're REALLY keeping the weight down then it becomes a virtuous circle rather than a vicious one, ie:

Big tyres need big axles and that needs a big engine to push it along, but you need a big heavy gearbox and t-box to make it reliable and a sturdy chassis to keep the whole thing together = Heavy Truck.

Big tyres but geared down means lighter axles, so less engine required and then a smaller gearbox and less chassis stress through the same manouvres.

So - set yourself a vicious target weight and go for a 1.9 XUD9 turbodiesel engine? Early models meet all the "hammer and tights" requirements, just need a wire to the stop solenoid...

[will_warne]

PB, lots of good advice here. As has been said think about what you want to do with the car. If you plan to do any long distance events you need speed and that means you need power. That can be difficult and/or expensive. Yes there are cheap lumps out there but you may have to do a lot of head scratching and machining (eg engine to gearbox adaptors, gearbox to transferbox adaptors). If you can't do the latter yourself then you'll easily blow your budget on machining alone. Also think about management as an engine is only as good as the management system - MS can be good and is cheap but it's half your budget.

Also, not wanting to put a dampener on things, but seriously think about your budget. To make a car that can survive several days of hard driving is not easy and, unfortunately, you need some expensive components just to be able to complete the event. Expensive cars are not expensive because the builders want them to be expensive - the parts alone cost big money. Rather than saying "my engine budget is X" say what the build budget is in total and start to prioritise. Also, can you afford to compete in these large events where the entry fee, parts bill and fuel bill could easily be more than your engine budget. Even people like Jez who make the money really stretch have to spend on some things like engines, gearboxes, suspension, axle internals, tyres, steering components etc. There seems to be a lot of stigma in the UK about people spending money on cars. Unfortunately it has to be done sometimes and if there isn't the cash there then it isn't much point only being able to half build a car.

OK, assuming the budget stands and you want a speed car and have dealt with other issues (like suspension) it then comes down to how light the car will be. If you were able to get seriously like I think something like a 2.3l Ford Duratec (with or without forced induction) would be a good choice as it's very torquey. The ford / jag 3.0l V6 is also a nice engine with a good powerband. The same is true for the Jag V8s (either nat asp or supercharged). Honda and BMW also make some excellent engines with the former having some superb variable valve timing technology. However, all of these are modern engines and you would struggle to get them running for your budget. You then come onto things SBCs (with Ali heads) and RV8s which may well fit the bill but will also be on the limit of your budget by the time you get them running reliably. Personally I'd try and stretch the budget a bit as that will open up the possibilities.

[Lara]

Wow Will !!!

You are getting wiser and wiser AND doing your own build! IMPRESSED!

Good advice!

I think this is all pointing to a serious re-think! And a look at what others are doing with their finished and "running" vehicles!

Don't look at builds like mine (Ced's) or Wills or any other "in progress" vehicle as an example as we don't know whether they will work yet as they are not "tested" This is very important! anyone can build on paper and although we are fairly sure that our stuff will work you should not take our word for it

Look at the other vehicles that have done the events that you want to do and look at their approach. Their engines, Their suspension and their Weight etc!

Turbocharger has a good point, but remember that although you can gear down a small engine to pull big axles wheels etc you will surely loose the speed!

And do not under estimate the drag of a big bogger in deep Mud!!! you will need some grunt to spin those up!!!!

Lara

[plasticbadger]

There's some great ideas coming, and some good advice.

I think I indicated that the budget I said in the begining is more of a statement that I don't have a blank cheque, rather than a fixed limit. Ideally I'd spend out on a donor car and strip that for spares to get the engine for that 'effective' price (i.e. donor for £1500, less £750 from breaking = £750 spent). Anyway, I have done as Will suggests and thought of an overall budget, then prioritised. By the time items like steel, body work, axles, tyres and suspension harware including coilovers are purchased the running gear budget looks pretty meager.

I'd be happy to spend out the budget I set out on day one and then have to add to it later for injection, materials for adaptors (I can do most of the machining, depending on how complex it gets), cooling, etc.

Weight wise the car will run Unimog based axles, which will be heavy, but with a well engineered tube chassis, sensible wheel and tyre combo and middle-of-the-range drive chain I am estimating around 2000kg dry, bare weight. At which point I thought 200 hp / 200 lb/ft would be a sensible power to aim for. Unfortunately that puts the Pug diesel out, or any of the NA car options. Any of the V8s could tick that box though.

As for the events, so far I've looked in detail at Ladoga, TAT and Croatia. The problem is the vehicles vary for each. I certainly feel Portals and decent suspension are a must, but TAT competitors prefer smaller more nimble machines than either Croatia or Lodoga.

At the moment my choice is swaying towards the old technology, firstly as they'll be easy to field repair, secondly because I wont need expensive one-off ECUs, adaptors, etc. However carburetor feed Chevys wont like the angles I'll get too (don't think LPG will be easy to get to the middle of an eastern european forest) and the diesel options are heavy. That said I've always like the 4.2 Toyota diesel, would go nice in a defender size truck!

Presumably Megasquirt could be used on the likes of Lexus V8s?

[dollythelw]

Petal evo stood me in at less than most of the UK boys spend on thier front winch setups and it was a ballistically fast car, not because it had super turbo anything - it just worked as package and you kept your foot down when others backed off. It had a 210,000mile, £50, 2.8 Isuzu (with a series of cheap and simple violations performed on it) under the bonnet.

4.2 cruiser is a boat anchor in a race car IMO, great engine otherwise.

Lexus - it was easy, the early models had 1 ECU for the motor and another for the transmission, later units integrated both functions into 1 ECU. Even thats not tricky - its a motor, suck squeeze, bang blow, megasquirt would drive it, Lexus forums are a wealth of information, TLC transmission will hook up shove a pair of turbos on sized to give 4-6psi from the bass end and you wont be short of stomp, I was bored at work and priced a self built, cheapskate, twin turbo Lex up to be just under £1k.

5.7 SBC - way sensible, every tuning part known to man available (and cheaply at that), cheap transmissions with usuable ratios limited to mostly autos, Gaz 66 or volvo 303 transfer box makes cheap and strong, octane booster will be your friend, injection is simple - they will run at very silly angles then. You're right about LPG, it would be suicide.

Supra 6 banger, turbo or not - monster strong.

VAG1.9 sensible up to Tr3, not enough grunt for big tyres

Forget the carb verses injection bit - the only reason people field fix carbs is because they break in the field, injection wins hands down.

I'd seriously reconsider using 404 axles though (if at all possible), toooo heavy. factor in "grey weights" (driver, navigator, fuel loads, emergency rations, fire extinguishers, winches, recovery kit, dry kit, tools etc etc) and the ability to loose lard from something as straightforward as a different axle choice becomes very tempting, 404s will further compound sprung vs unsprung ratios and make suspension tuning "entertaining", there are no fast trophy trucks with 404s under them that Im aware of.

I dont understand your point about building a specialist truck, just swap wheels and tyres and enter whatever you like, theres no reason why a portal car cant be considerably lighter and the same width as a standard defender, just get busy with the bacon slicer

[lansalot]

If you only megaspark an RV8 instead of the full squirt, would that be any significant saving ?

(hmm. I may be talking out of my ass there...)

[FridgeFreezer]

Presumably Megasquirt could be used on the likes of Lexus V8s?

Megasquirt can drive anything petrol as long as you can mount a fuel injector somewhere in the intake tract.

If you're on such a tight budget then you need to prioritise, some things are easier to change later and some aren't. You can start with standard suspension which costs 50p and then move to coilovers later as money allows (and what's the point buying cheap coilovers when you could buy good normal suspension for the same money). The car can be engineered to be easily changed if you later fit different components, keeping the options open.

Engine/gearbox/transfer box can be changed later although not without some hassle so it's nicer if you have an upgrade path - again, the RV8 does work well here as you can start with a peanuts 3.5 EFI and go all the way to 4.6 with only a set of spanners and a tweak of megatune. Other combos such as Toyota/BMW lumps may also offer that opportunity. Ultimately though on a budget of less than £1000 for a complete 4x4 engine/box/transfer you've got to be looking at buying a complete vehicle to break, be it Rover, Toyota, whatever and just pulling the whole combo out in one piece. Adapters to mix & match transmissions are going to introduce time & money & could introduce unreliability issues that you don't get with a known combo. If you later want to add bling transfer cases, uprated boxes etc. then that's always an option.

Not sure about Ladoga cars being heavy, you obviously missed the one made entirely out of carbon fibre there is also some awesome stuff built for no money, shows what can be done with a bit of engineering. There are a lot of cars around Ladoga and the other trophy raids doing very well which are local Gaz/Uaz jeeps, SJ's or other jap stuff which would cost sub-£500 for a decent donor car over here, with a cage, a homebrew winch and appropriate axles & tyres glued on.

The Spider, built by Anatoly on a budget of 37p - he made his own portals, his winch, his wheels, propshafts, steering, even his bellhousing was made from welded up plate. No two components on the car were the same because he had to use whatever he could find or scavenge from scrap vehicles.

[Daan]

Been reading this and so far not replyd. Its a bit of flying pig in my mind to think international events while spending £750 on your drivetrain. Given the attrition rate of the events you mention being about 50%, the answer is basically there. Cheap is possible, but I would think more about practical. A landrover engine might break, however any event you enter will have other landrovers about, which means spares. Getting spares for a Lexus engine? I mean where would you go for a lexus headgasket in the UK for example, let alone in Russia.

Power, more power is nice, but less reliable in terms of your mechanicals, cooling more critical etcetra. Usually your gearbox is going to cost as much as the engine, if not more. I personally didnt find my TDI lacking power, but other factors slowing me down. So if I were to go for a big power increase, I would also need a fast ratio steering box, and some groovy shocks before it is useable.

An entry fee to Ladoga is about as much as your drivetrain budget, the ferries the same (if your not trailering). So I would think it would make sense to sort out what you have and have a go with that to see what its like and then decide on your new build spec.

Just being realistic. A realist is an optimist with experience......

Daan

[dollythelw]

why would a Lexus blow a head gasket Daan? but the answer to your question would be St Pete, anything Jap is available there, conversely the Landrover main dealer promised he can get parts "sometimes in under 3 weeks" yay........... relying on other competitors to hand over the parts they know are potential failure points on thier own vehicle to keep yours running is at best, chancing it, add in the fact that ANY landrover part costs multiples of what they do here and it becomes a lot easier to understand.

Personally I go with the premis of "in places where spares are tricky to find use a bombproof motor" (theres no dealers for any make of vehicle in the woods), landrover motors seem to autodismantle almost everywhere!

For the race car we dont take any head gaskets, water pumps, pushrods, rockers etc, we also carry no spare diffs, halfshafts, alternators etc etc etc

thats based on experience as well

Im not advocating one motor over another - merely suggesting that expensive isnt always right and landrover motors are not the ultimate pinacle of engineering in terms or performance, weight, strength, reliability and spares availability

[plasticbadger]

Been reading this and so far not replyd. Its a bit of flying pig in my mind to think international events while spending £750 on your drivetrain.

I don't think that's strictly true. Tdi, RV8, Izusu (as Jez had in Petal) can all be done for pretty much nothing - and would get the job done. My current RV8 and auto have done less than 20,000 miles and cost £750, in an MoTed Range Rover. As I have said before the budget is an indication that I can't afford to go out and spend £1500 on an LS1, £1500 on a transmission, £600 on an ECU etc. etc.

I can afford to spend out on coil overs, proper grades of steel for the chassis, navigation gear, rebuilding my trailer, all new tyres, winches, entry fees, the costs of getting to the events and so on. I just want to know that when I'm building the car up as a package I've thought of the options - even if that means I go with something like a standard 3.9 RV8 and upgrade later to a sorted 4.6 on MS.

The Russians and Eastern Europeans show that you don't need £,000's to build a competitive car and I thought by tapping into the combined knowledge of the forum I could come of with some good options for emulating them.

The discussions on this thread I think so that getting an engine and box for my budget is easy, getting into the car and working may cost more.

[dirtydiesel]

Isuzu 2.8 engine makes a lot of sense.

Another option i've given a lot of thought is the granada cosworth v6.

Ultimately it all comes down to personal choice.

For me it has to be a nice simple diesel that i can fix in the dark with little more than my fingernails, feel i can tade any amount of power for a rugged, reliable, simple lump that i understand every aspect of.

In my (in build) tr2 car i'm using a tweeked 2.8 isuzu based on the following reasons;

it's a lot lighter than a tdi,

tweeked to death they just don't make heat,

they rev free'er than tdi producing more power and torque in the process,

smaller than a tdi in every dimension,

come with a lovely gearbox on the back that doesn't go wrong.

and i know them inside out.

[FridgeFreezer]

landrover motors seem to autodismantle almost everywhere!

Excuse me - Land Rover TDi's may auto dismantle everywhere, my RV8 hasn't skipped a beat in three ladogas.

The point about tuning is bang on Daan - the more you tweak anything the less reliable it gets and the fussier it becomes about cooling, fuel quality, etc. Far better to find a standard engine that makes about the right power than tweak something up till it screams.

I'd also echo Jez's comments about spares - everywhere else in the world LR is a luxury brand like Jaguar, if people want a rugged utility vehicle they buy something japanese or something local. Again, you need to look at what the locals drive and how they do stuff as the chances are they know their onions.

[Hybrid_From_Hell]

One thing to do is your research before handing over the ££££s for an engine on a crate "All Complete"

As has been said some modern engines are a complete Barsteward to get running out of the donor car

as the ECUs can have all sorts of wizardry built in for all sorts of reasosn, and you'll either need to find out

HOW to get around it , and or , once you have this info the costs of doing so.

Also be aware I know of a V10 Merc engine that was bought for a racer all complete, the ECU alone was one problem

some bits were missing and I seem to recall a discussion later about the nightmare of "Coded Injectors" which means

in simple terms its not a fit a new one in the missing space and fire it up.......

Narrow down to a suitable few engines then go find the repective forum of knowledge re the above, and of course

come back and educate us all

Nige

[moose]

I now completely agree with dolly about 404 axles but iam sure PB you will prove me wrong

doesn't the Isuzu 2.8 engine have an unsealed cam belt cover.. would this not be problem in swaps etc.. if not i might start looking at this for myself

you need to look at what the locals drive

where i went the quite a few of the locals drove:

and even these where not with out problems:

[plasticbadger]

Are the helmets really necessary?

PS> 404's will be narrowed and disk brake clad, so some of the weight will be lost. They'll still weigh the same as an SJ

[FridgeFreezer]

doesn't the Isuzu 2.8 engine have an unsealed cam belt cover.. would this not be problem in swaps etc..

Computer says no.

[dollythelw]

doesn't the Isuzu 2.8 engine have an unsealed cam belt cover.. would this not be problem in swaps etc..

Petal never skipped a beat, water gets in, water gets out

[will_warne]

One more thought I had today - look at the results for Croatia this year. A UK run TD5 car on Simex did very well. Not that special but with VERY good suspension. Ditto what Jez said about Evo Petal: it didn't have all that much power but he could put more down, more of the time. The same was true with Jules Read and his 1.8 Freelander racer. Because you're obviously on a tighter budget might it be worth thinking about spending a big chunk on good suspension and hooking it up to some smaller axles (be it portal or not) and run some smaller tyres (like a true 37") with a little less bhp (180 - 200)? Yes, it may not get you so many comments down at the pub but you may be faster and have more fun as the car will drive so much better.

I'd also agree with Jez on parts - Land Rover are hopeless for support outside the UK but most places will have luxury car dealers (be it Jag, Lexus or Merc) and they will tend to have pretty good support as their customers tend to be quite important and get rather unhappy if the service isn't good! I have to also admit that the 2.8 Isuzu seems to have stepped up to the plate on quite a few occasions now and given good results. That would certainly satisfy the cheap requirement

[plasticbadger]

Some useful advice, however I would comment to Will that as you've seen from my previous posts I have already built a Range Rover on 80 series Landcruiser axles and 37s, so if my question had been 'how do I compete in Europe as cheaply as possible?' then the answer would clearly be 'sort your Range Rover out'. But the question was 'I'm going to build a tube frame truck on Portals, what engine should I use?'

This is a strange move, true, but I've seen how portal trucks on big tyres perform in the rough stuff and I'm smitten. Plus I want to do something creative (which I could do to my Rangie, but it seems a shame to cut it up).

I am indeed on a tighter budget, but as I've said before I've looked at the overall budget and already allowed for coil overs etc. and really just wanted to keep the running gear lower budget (maybe only for the first year or two before upgrading) hence the 404s, rather than Volvos. If I said I had an unlimited budget, what would be the answer then?

Anyway, looking at Croatia, Ladoga and TAT, I see that the most commonly used vehicles seem to be Mercedes G, Nissan Patrol GR and Landcruiser series 70. So would basing my build on one of these be a good start?

[nicks90]

you took the words right out of my mouth by saying merc G wagon!

if i had the money, skill, time and inclination i would jsut start with a mid 90's mercedes G wagon with the easily tuneable 5cyl diesel and fit portals and put it on a MASSIVE diet. Probably just chop the whole lot off behind the front seats and turn it into a ghey-back with the rear chassis being a bit of tube instead of half a planets worth of merc steel box section. You could even do the same to the front as well. Just leaves the 2 chassis rails under the bulkhead and front seats and the main cabin as merc - the rest can be ally sheet glued to some tube.

then you have bombproof, power and portals. Job done.

[dirtydiesel]

you took the words right out of my mouth by saying merc G wagon!

if i had the money, skill, time and inclination i would jsut start with a mid 90's mercedes G wagon with the easily tuneable 5cyl diesel and fit portals and put it on a MASSIVE diet. Probably just chop the whole lot off behind the front seats and turn it into a ghey-back with the rear chassis being a bit of tube instead of half a planets worth of merc steel box section. You could even do the same to the front as well. Just leaves the 2 chassis rails under the bulkhead and front seats and the main cabin as merc - the rest can be ally sheet glued to some tube.

then you have bombproof, power and portals. Job done.

A mid 90's G wagon will set you back 4K minimum,

Will not come with a 5 pot diesel (463's 1991+) use a 3ltr straight 6.

And most of the weight on a G wagon body is the bulkhead wiring and the floor of the cab.

A nice 463 G would make a good luxo overland barge but not the best place to start a lightweight comp motor

[plasticbadger]

A nice 463 G would make a good luxo overland barge but not the best place to start a lightweight comp motor

My thoughts exactly Dan, since you're here can I ask your opinion on the Mog 404 axles? I'm planning to do similar to you with narrowing, offset swapping and disk brake conversion. Are they too heavy for what I'm planning, or can they be made to be a good balance between cost, strength and performance? And how have you found them in combo with your Tdi motor?

I presume that they're not ideal otherwise you wouldn't be making the Vitara with GQ axles and Isuzu engine

[FridgeFreezer]

My thoughts exactly Dan, since you're here can I ask your opinion on the Mog 404 axles?

Ooo, I know this one: They're not heavy enough for him