S16 Engine Building Advice

[hcmini1989 16]

Im building an xu10 lump from an s16.Now ive been looking about at what people upgrade on these and would like a few questions answering

 

Im throwing a 1.9 diesel crank in it .Should i bother upgrading the bearings (shells) to some race bearing or are the standards fine?.

 

do i bother fitting ARP rod bolts?.Ive seen lots of people fitting these but are they necessary ?.Its not going to be a full blown race engine .Just upping the compression a little

 

Should i fit a gti6 head?. from what i can gather these are a better head maybe not as stout but better flowed etc

 

What headgasket should i use ive been looking at cometic gaskets are they any good?.Is there any other makes about that i could use.Or could i use the standard Gti6 one is this MLS?

 

 

Cheers for any help guys.

[Miles 331 1 Cars]

Whats the rest of the spec of the engine, I know that with the 1.9 Mi crank the trust washers are a right pain so keeping it std CC keeps a good value to the engine and with the basic bolt on mods over 200bhp is quite easy,

 

Don't bother with the 6 head

[hcmini1989 16]

Pretty much standard miles i was gong to put a diesel crank in (forged) and keep it standard sized pistons with new rings.Was maybe going to get the rods shot peened .The cams i was going to use petert stage 1s .As for manifolds i was going to run some throttle bodies and standard exhaust manifold.

 

What do you mean a good value ?

 

The reason i was looking at the 6 head aswell as it ups the compression ever so slightly .

 

Im just after a reliable track/fast road engine .WIth something like 200bhp .

Edited January 16, 2013 by hcmini1989

[petert 586]

If you desire 88mm stroke, that should be the starting place. As Miles said, getting the thrust washers correct can be tricky. I've jagged it with std 1.9 washers before but you may not be so lucky. When you've got that correct, then plan the rest.

 

Pushing the piston 1mm up the bore does three things. Increases CR, decreases valve-piston clearance and makes the top ring work in virgin territory.

 

CR - this will be over 11:1 with an S16/Mi16 head. So adding a GTi6 head maybe too much. Probably around 11.5:1. With 11+:1 your cranking pressures will be too high for the Stage I cam. I'd recommend a bigger cam.

 

Valve-piston clearance - you'll need to measure and correct this by milling the pistons. Bigger cams mean more clearance.

 

Top Ring - Unless you have a very low km block, I can't see how you could do it without new pistons.

 

Staying with the standard 86mm crank is not such a bad thing. My favourite is to deck the block 1mm. This gives 11:1 and will be right on the limit of the Stage I cam, in terms of valve-piston clearance and cranking pressures. I'd still probably go for a bigger cam.

 

Std head gasket, std rod bolts, close & hone the conrods however.

[Miles 331 1 Cars]

I say cheap but the couple of S16 engine's I have done I have left the bores alone as I;ve had allot that become U/S unless bored out due to excessive bore wear which is another reason to say 2.0.

With bolt on mods with CAT Cam's, Throttle bodies (Jenveys) 4-2-1 exhaust manifold which is need as the std one is poor and can hold you back 10 bhp from results I have seen over many years without any work to the pistons etc you should see over 200 bhp without any issues, the Dimma I did to this spec made 208 bhp and almost 170 ft lb of torque

 

You just cannot do this with a GTi6 spec engine

[hcmini1989 16]

Its not a low miles block in fact the opposite ,I spoke to my local engine centre and they said it should be ok as long as i honed it out .Do they mishape over time (the bores) therefore needing to take some meat away.

 

I was under the impression that the s16 pistons cut outs were big enough to allow crank and cam mods without milling ive probably read this wrong then .

ive read that much now its getting all jumbled up

 

Miles im confused here mate are you saying just build it with bolt on mods and not bother modifying the crank/stroke.

 

Btw im new to engine building so im sorry if my questions seem stupid .Hence ive no idea what the thrust washers are .I will do some reading now

[Doof 11]

Sounds very similar to my build which made 185 or so at the wheels without itbs. I used a Cometic Mls gasket. my engine is for sale but if you're insistent on building one maybe check mine and sartys project threads.

[hcmini1989 16]

Ive been looking at yours doof ,Shame your getting rid mate.Its a bargain at that price mate id dred to think how much that lump owes you.Ill have a look at sartys aswell cheers for the heads up,

 

Thrust washers im guesing your refering to the big end shells.If so i thought all XU ones were the same size?. Whats tricky about them?.

Edited January 16, 2013 by hcmini1989

[Miles 331 1 Cars]

The honing is what makes the block U/S, the piston generally wears the top of the bore so when you hone you are left with a huge dip which will kill the top ring in 2 mins, If done allot I really would leave the bores alone if OK as said the amount I have tried is silly and why I gave up doing it.

 

The S16 pistons are fine for cams at the std bore, If using a longer stoke you will need to do a dry build to check clearances, Mind I have no idea on Peter's cam spec's so go along with his advice there.

 

With the power and torque I know can be got from these and knowing the issue's that 'CAN' arise I'd leave it at 1998cc and do the spec as above for a nice little engine

[welshpug 1,657]

I have an average mileage S16 bottom end, I can clearly see the rings past the side of the pistons

 

thrust washers are just that, thrust washers, they are not big ends...

 

http://www.qclt.com/html/%E6%A0%87%E8%87%B4206_406/406D9/INFO/gb/b1cj0bk3.htm

 

 

part number 9.

 

[Miles 331 1 Cars]

Only the 1.6 and 1.7 use smaller Big ends, But as odd as it may sound they seem to fair much better

[hcmini1989 16]

Ok thanks for the input guys ill do some re-thinking to my set up .

[petert 586]

,I spoke to my local engine centre and they said it should be ok as long as i honed it out .

 

He's pulling your chain. If it's long in the tooth, either leave it as is, as Miles said, or completely rebuild it. There's no in between with these. I'd bolt up a gearbox & starter and give it a compression test on the ground before making any more decisions.

 

Just to verify what Miles suggested, my current daily driver is an 1.9L Mi16 with an elcheapo S16 engine I threw in. The only mods are Stage I intake cam, 1.9L inlet manifold & injectors, aftermarket management and GTi box with 4.4 cwp. I'd estimate it makes around 185hp given how well it goes.

[Vili 18]

My engine is quite close to what you're planning to build. I had to try couple different thrustwashers but got the clearance (endfloat) within the factory tolerances. I used 1.9 mi16 crank and std. S16 pistons. I didn't bore the cylinders but I had two block to choose from. The other block was so worn that it would have required rebore for longer crank, but the one chose has been running fine with just a hone and new piston rings of course.

My inlet cam has 10,8 mm peak lift which may be fine with 86 mm stroke but with 88 mm stroke I decided to deepen valve pockets by 1,6 mm.

I use mi16 inlet manifold with bigger throttle and the exhaust manifold is d-i-y. Power wise I'm not sure but it tells something that std. injectors ran duty cycles past 90% at 70% throttle opening. Currently I'm using Saab Aero injectors.

I would be better of with bit more cam since knock is bit of a issue.

Aftermarket ecu is must with this kind of combination as the engine is actually quite far from the stock engine.

Edited January 17, 2013 by Vili

[wicked 103 3 Cars]

Lift at TDC will determine the pocket depth, not the peak lift.

 

Easiest and cheapest solution is to buy the engine from doof; can't build an (uprated) engine for that price.