Xu5 J4 Conversion

[renault 17 1]

I've just finished my 1599cc mi16 project and was interested to read some of the old posts about the conversion. I've used the standard crank with competition bearings and It produces peak power (198.7bhp) at 8226rpm. I had many issues when building it, had to skim the block/liners by 1.6 mm and machine the squish area in the head to let the pistons move up enough, I used omega racing pistons for the 1.9 with deeper valve recesses but still ended up with minimal clearance. I've used it for three events without any bother and it sounds and goes very well. Just wondering what other peoples experiences of these engines are and mainly if it's suicide to rev a standard crank that high. a mate of mine has an 8v for years which he regularly revs to 8k without ever having any trouble. I tried to add this post to the old thread but wasn't able.

[welshpug 1,661]

crikey! whats the rest of the spec on it?

[brianthemagical 1]

crikey! whats the rest of the spec on it?

 

i was thinking that, then i looked in his sig.

[Hilgie 16 2 Cars]

sounds like a quality enginebuild!! could we have more specs? like which rods were used, headgasket etc?

[petert 588]

Well done on building a difficult project. Looking forward to hearing what rods you used. I guess we're all waiting to hear how long the crank lasts at 8200!

[renault 17 1]

You're going to shudder but I used 1.6 gti rods, I haven't heard of them blowing up yet hopefully mine won't let go either. The little end was narrowed to fit into the piston and have enough side to side clearance, with the big end resized to standard with ARP rod bolts the pistont have had holes put in them for lubrication and the pins are press fit. I'm making a bebo page about our rallying (just a laugh) www.bebo.com/karclub and there are some pictures on it. I'll give a full extremely detailed spec tonight if i get a chance. I hadn't realised there was so much information here which could have saved me some headaches.

[renault 17 1]

Any Idea where I'd get a billet shaft, It pulls like a train to 8500k,

[Hilgie 16 2 Cars]

Farndon does billet shafts. http://www.farndon.com/crankshafts.htm

[renault 17 1]

They're a little pricy, I was just wondering if anyone might have one taking up valuable space somewhere that I could relieve them of. Seriously though, I'm not too worried about the crank, unless I get oil issues it should be ok, but I think the weakest link may be the rods and I'm not so sure how weak they really are. Hmm, how high do other people rev their 1.6s I wonder.

[VisaGTi16v 1]

Dare I ask why you went with a 1599cc? I presume to get into a 1.6 class for some competition series?

[renault 17 1]

Dare I ask why you went with a 1599cc? I presume to get into a 1.6 class for some competition series?

 

I'm just starting rallying and I needed a 1600 for the first few events and thought this would be an interesting way of getting good power for a 205. I had gone too far to change by the time I realised fully what was involved.

[Sandy 191]

That's a good result!

[Chris H 10]

My housemate built a very similar spec engine, 1.6 crank and rods, mi hi comp pistons, decked the block and liners and topped it off with a pair of cams and a solid follower conversion. Its fuelled by a set of 45 cabs and has a maniflow manifold......it makes aprox 200bhp at the wheels too! He has only done one rally with in it and was 2nd overall till it all went a bit wrong with a combination of puncture...armco...trees....roof etc!

[taffycrook 2]

I know of and have worked on a few 1.6 rally xu16v's.

One was done with a no limit budget, makes around 220 bhp the other is a club car and was done on the cheap.

Block decked, liners and pistons machined.

The rods were custom jobs to enable use of the std mi pistons. Std crank mind.

These cranks seem capable of high rpm but the limits must be close at 8200 rpm.

power was close to 200 bhp and it is very quick.

It can be done but there are better 1.6 std motors that can be tuned for this class of rallying.

[Batfink 201]

I can't believe I missed this thread. Whats the reason for not using mi16 rods - too long?

As for cranks - would getting two made at the same time be cheaper as I need one. I'm looking at catcams though

Edited November 7, 2007 by Batfink

[B1ack_Mi16 67]

I can't believe I missed this thread. Whats the reason for not using mi16 rods - too long?

As for cranks - would getting two made at the same time be cheaper as I need one. I'm looking at catcams though

 

Mi16 rods will be too short afaik, as the crank throw is significantly reduced so need longer rods.

[Batfink 201]

ahh I see. Yes thinking about it thats pretty logical

[petert 588]

In addition, Mi16 and 1.9L rods have a larger rod journal. To make the perfect XU5J4 you need custom pistons and rods.

[welshpug 1,661]

is there nothing at all oput there that would do? IIRC BlackMi16 used steel M3 rods for his 2.3 Mi, so there might be something out there to suit??

[B1ack_Mi16 67]

is there nothing at all oput there that would do? IIRC BlackMi16 used steel M3 rods for his 2.3 Mi, so there might be something out there to suit??

 

What's the size of the rod-journal on the 1.6 crank then?

 

I used BMW M3 spec on the big ends on my rods, but apart from that the rods were ordered with custom length and pin size, so they were basicly custom ones.

Reason for going for smaller big end was because I reduced crankpin diameter to gain stroke.

[Sandy 191]

1.6 crank has 45mm big end journals.

[snillet 1]

Before i put in the modded JAZ engine in my car i was running the stock XU5M BDZ engine but with a XU9JAZ DKZmanifold and a XU9JA D(???, the 128hp one..)camshaft, head on the BDZ is the same as on the DKZ and the 128hp engine so it´s equipped with quite large valves for a 1.6, was revving fine up to about 7500rpm like a little mule, but after that the valvesprings started to "slip"...

[Batfink 201]

right i'm going to dig up this thread rather than start another. For some reason I was dreaming about engines and I was wondering if you could deck the mi16 block so you could use a standard mi16 piston and rod with a 1.6 crank.

 

Would it be a simple case of decking it 15mm??? (difference between 73 and 88mm cranks)

 

Of course you will need to do the same to the liners but I feel there is something blindingly obvious that I am missing that will make this idea impossible.

[Hardcharging 0]

I was thinking along the lines of ...(Batfink's question)

 

Loosing 15 mm off the block,

.

 

Would mean finding a cambelt 30mm shorter.

 

I have toyed with the idea of a 1.6 16 v but it seems a bit of a never ending story

[Batfink 201]

i've just been chatting to Matt at QEP and he said that the mi16 rods wont fit the 1.6 crank - you have to use 1.6 rods with the 1.6 crank - which is a shame!

Certainly its a case of if you want a 1.6 mi16 then dont

If you need one (for a race series etc) its complicated and expensive lol