Building A Tu5J4 Rally Engine, Where To Start?

[welshpug 1,627]

I know the sensible thing would be to save more money and get on Sandy's waiting list, if he would be willing to take another build on, however the owner/driver would like something a little cheaper and sooner than a year away

(not that its a bad thing, sandy having a years waiting list, shows he's doing it right!)


Unfortunately given the fairly low popularity of high power n-a tuning of these engines there isn't a great deal of off the shelf parts like pistons and rods out there, I understand Sandy uses Carillo or Farndon Rods which isn't a problem in itself to source as specifying a rod is not too tricky.

However when it comes to pistons I've no idea where to start with doing a design, understandably guys like Sandy don't want to show everyone their hard earned design, nor do they have time to supply something suitable with the current workload.


Inlet wise we already have a Satchell/Brown GSXR setup, donor engine we do have a complete J4 engine with around 50k miles on it, currently still with standard valvetrain and fast road cams.

we have spotted a very low mileage J4 block which would be great to do a fresh build without boring, as this would take it over the 1600 class limit if it were taken to a standard ring size.


valve sizes, there's great evidence across the pug forums that standard are the way to go, though one piece possibly with a different shape is preferred, especially for a solid tappet with rally use intended.

cams, open to suggestions here, not keep to go Cat given the longevity issues I have heard of, happy to use Newman as I've experienced them myself.



cylinder head work, if possible, we would send the head to sandy, however Automotive engineering is around the corner from Garry (the guys formerly at QEP) so nice and local, but I'm not so keen as in initial chat they have gone straight for the big valve hard sell.

plenty to think about!


current engine is also a J4 running cat 850 solid profile with solids and springs, standard head crank PEC rods and pistons, piper exhaust manifold satchell inlet, runs around 142 lbft and 170 bhp IIRC.

the aim is to have pace nearer the R2 spec rally cars, so a power and torque figure above what they run would be great, it doesn't need to be a full on 225 bhp super 1600 engine, however looking at the rough cost of parts to build 190 and 225 bhp, there's nothing in it and thoughts of going all out are there!!


(I know many current R2 cars are only 170-180, but have an immense amount of money in development and dampers, sequential gearboxes, and most importantly usually a Bonkers Belgian at the wheel!!!)

[Redtop 14 2 Cars]

Does it have to be a Peugeot engine? To get near the pace of an r2 car in the likes of the brc is going to be very hard, considering at the ulster rally this year, a local man was quicker in a fiesta r2 over some stages compared to one of the main frotn running men in the national rally in a wrc Subaru, who's been about for a long time and is quick.

 

I have an R2 car myself, although not at brc level yet, but when I have done a few rally's in against the modified 1600cc class, generally the people have engines from 200-215bhp, to be on par or quicker than the other r2 stuff on the stages.

 

The favourite engine at the min over here in Ireland, is probably the Honda 1.6, as value for money it is easy enough without major cost, to get to 190bhp+. Maybe worth considering if car in question is in the modified 1.6 class? I know it has been done with a corsa over here and seems to work ok. Also some of the civics have went to sanz sequential boxes, so I'm sure if you have a good fabricator that could be a possible upgrade down the line too.

[welshpug 1,627]

no, its a Citroen

 

 

but yes, specifically due to the regs in Belgium where the car is predominantly used, you can only use the same manufacturers engine, whatever it is however, so a V6 Cosworth in an escort is allowed AFAIK!

 

Martin Fox (MEF motorsport) recently built an S50B30 engined 1 series partly with Belgian rallying in mind, the 1 never came with that engine, but its a BMW motor still, so it is allowed.

 

Certainly a 16v Cosworth in a mk2 is, or an XE in an old kadett.

 

An XE for example in a MK2 escort is a big nono and you rarely see more than half a dozen escorts in fields of well over 120 cars, mostly good spec pinto's and a few rare BD.

 

 

It is a Saxo so its not specifically an R2 car, but its in the same modified 1600 Class out in Belgium when used there, and the up to 1600 class over here, its a tarmac car, never sees gravel except on the mixed surface stages they often use out there.

[Mad Scientist 106]

http://m.youtube.com/watch?v=EfZflcY8SzE&desktop_uri=%2Fwatch%3Fv%3DEfZflcY8SzE

 

You ever seen this guy?

 

Regularly gets seeded above wrc cars, and regularly shows them and the big power escorts a clean pair of heels.

 

80% balls/commitment/talent

19% clicky box/decent suspension

1% half decent 1.6 engine

 

Now, I'm no one to say chasing power is a bad idea.............but will it really make him faster??

 

Badly done, he could lose tractability and actually be worse off.

 

The problem is though, power corrupts..........

[Mad Scientist 106]

By the way, he was 9th overall on the promenade stages last weekend. Pretty much tit for tat with a wrc escort cossie, driven by a bloke who is a pretty good peddler himself.

[welshpug 1,627]

Can't make the driver faster, still got a slow car, relatively!

 

If we can get up to speed sooner, then Garry can afford to be less bonkers than the other guys, but I totally accept what you're saying, we are unfortunately regularly beaten by heavier very similarly powered R2 cars, and very basic spec single throttle body and even 8 valve 106's and saxo's!

 

 

Last rally was won outright by an S2000 Polo, beating a 400 bhp+ 130i a few GT3 porches and many ex-WRC cars, in amongst them was an R3 2.0 clio (250 bhp single throttle body) and not very far behind a C2 R2 max, which was a few minutes overall in front of the next R2 car which garry was swapping seconds with.

 

Belgian stuff is much faster than British more often than not, and typically square junctions and not that much slow nadgery stuff.

[Mad Scientist 106]

To be honest, if that's what he wants to do, go for it. I lead by example! I'll never be competitive in my class, both through lack of skill and having the wrong car, but I enjoy it, and I love my engine, and all that went into building it. There's no doubt, I'll do it again!

 

Best piece of advice is try and avoid getting too many people involved. That's why having someone that takes ownership of the whole build is a good idea. Sandy may be too busy, but there are alternatives. Whether they are lesser alternatives or not is up to you to decide. Brett Simms? SRD? From experience, I'd avoid the people you have already mentioned.

 

In any case, to do this right, you will need lots of custom parts.

 

Rods: going to need to be longer I would have thought.

Pistons: adjusted pin height to suit, optimised squish etc.

Cams: I doubt anything off the shelf will get you what you are after.

Head work: can of worms, but I'm not sure standard valve sizes are what you will need. May need some careful adjustment of valve seats to fit the cams in etc.

 

 

It truly is a minefield! Lots of headaches, but worth it in the end. Even better if its not your money!

[welshpug 1,627]

Just to update, general verdict was that a worked head would unlock possibly up to 20 bhp.

 

First guy Garry spoke to straight away went for the big valve hard sell, which I can sort of see why, as the JP4 cylinder head has much larger valves as standard, however different shape ports afaik, and different inlet manifold stud pattern.

 

I did also speak to sandy who did not say anything about larger valves but did reccomend single piece valves to cope with the high RPM, and could supply a cam profile suitable for the head port shape and usage.

 

 

Garry did drop the head off with the local guy, as he said he could get it turned around ready for the next rally which was scheduled to be at Kortrijk and bolt it down onto the current bottom end, just to see how well it would work over the budget rods and pistons, then look to get a Head from Sandy and some rods and pistons to a recommended spec by Sandy, and assemble it ourselves, without aiming for a specific power output but 200 would be good with a well rounded character.

 

However, Garry has gone a different route to getting 200 bhp, and a sequential box....

 

 

[welshpug 1,627]

Thought I'd add a brief update to this, due to certain issues with the engine the new car came with, the 170 bhp engine from the old car was pulled out, its original fast road engine put back in, the Satchell bodies bolted on and sold on complete, to be seen out on the stages already!

The new owner seems happy with it from all accounts, but I do hope they get a proper map on there, as its not a map for that engine or cam spec, it does have an S40 ecu so a trip to Cornwall should get it running sweet.



To recap, the 170 engine was a cat 850 with solid double sprung valvetrain, PEC rods and pistons, early Satchell inlet and a piper manifold, the head casting was 100% standard J4.

Unfortunately due to poor mapping and air leak issues the pistons were found to be pretty shot when the engine was stripped down for a refresh, which is rather frustrating when a decent lump of cash was outlaid previously.

The head was sent off to be reworked, I believe it will have JP4 sized valves now, new pistons fitted, as the Satchell inlet went off with the old car, a new Jenvey inlet was supplied and fitted.



Update on the car itself, is that it has a Satchell widetrack front suspension, the widest they've done to date, with new matching length driveshafts, the over complicated fuel system was binned in favour of an uprated intank pump

(yet to see if Garry has conformed to my insistence of a fixed rate FPR though, having seen several instances when Sandy has been mapping of pressure creep on adjustable units)

Due to timing the engine was not ready when the car went down to Cornwall, and the car didn't come back for a few weeks after the engine was completed, so I couldn't persuade Garry to make the trip over the border for mapping.

First fire up after many jobs were ticked off the list was last Sunday, and Garry took the car for mapping yesterday afternoon, I got a brief email last night, 190 bhp, and plenty of torque, "its savage like a rabid dog" driven it round the block up to 2nd gear, mapper said the manifold is holding it back (on a tony law manifold of unknown dimensions, and a Saxsport system!) could hit the 200 mark with a better manifold.


First event is a rallysprint this coming weekend but I don't know if Garry will make it, he's very happy with the work from the Satchell engineering guys, and word from my mate Kev who also helps with the servicing and building, is that with hindsight probably would have just gone to Cornwall for the engine...

oh yeah.