1587cc TU5 pistons and tu5j4 rods(vts rods) in a vtr

27th December 2009, 15:18

can anyone confirm these will runs in a vtr, prov bought the turbo conversion from member jason on here, hes sais the lad he bought them off ran them in his vtr but can anyone assure me these will fit my silvertop before i purchase, yes ive tried searching but nothing is of any relevance, should imagine the pistons will be no bother but will the rods go in with these pistons in my engine

27th December 2009, 15:25

they 16v pistons yeh? just watch the valve cut-outs if you're looking to run a wild cam with the turbo, if not then willl be fine

wide-vtr-turbo is running 16v pistons in his 8v engine.

Not 100% about the vts rods in a vtr - i'll try and find out for you

27th December 2009, 15:30

cheers mate really appreciate it, i think theyre 16v pistons too as i recall jason saying they had the valve cut outs.... dint know he was running the 16vs too, didnt know you could or i would have got some in that group buy...never mind lol getting these if theyll run

27th December 2009, 15:36

need to be careful as the one of the engines (jP4 for example) uses press fit gugeon pins for pistons and the other engine (i.e j4) uses floating... this could stop you miss matching

27th December 2009, 15:38

he said theyre floating so will be fine.... sounds about right to me but i just wanna confirm before i make an expensive mistake lol

27th December 2009, 15:39

my lump is the 90bhp silvertop

27th December 2009, 15:43

Quote:

Originally Posted by dannygti

need to be careful as the one of the engines (jP4 for example) uses press fit gugeon pins for pistons and the other engine (i.e j4) uses floating... this could stop you miss matching

Yeh, also have to watch the pin size 18mm vs 19.47mm (standard vts)

27th December 2009, 15:47

ill imagine the lad had bought them together new... and they have been used...plus jason bought them to go in his vtr lump for the turbo conversion he made up so im fairly happy they could fit but?? as said it would be an expensive error tbh like

27th December 2009, 16:06

budget for new rings to go with the pistons if they are used - could be £££, and when added to the purchase price of the pistons could be cheaper to buy new?

27th December 2009, 16:10

nope getting the kit with a set of brand new rings mate

and it will work out significantly cheaper

27th December 2009, 16:11

he bought the rings when intending to fit to his car, sais they were 100

27th December 2009, 17:03

anyone else shed an insight? looking at runnnig at urbo cam too so may have issues, is it clearance issues for the valve cut outs on the 16v pistons in an 8v?

27th December 2009, 18:16

Ok just to give an input on this, the Omega pistons were, up to recently, used by GMC and others for their boosted VTR & VTS conversions. The reason they were dropped for Wossner's was due to the higher price of the Omega's. Only one design was used for both engines because of the cost involved individualising when there was no need as both have the same block design. As the only issue with standard valve clearance is on the VTS (standard vts pistons have cutouts) and not on the VTR, the pistons were given cutouts to cover this. These pistons could be fitted fine to the J4 engine which has the floating type gudgeons like mentioned, but the VTR (TU5J2) engine and the JP4 engines use a press fit gudgeon pin setup, so for this reason either floating type forged rods (£££) or J4 rods are used to fit them to these engines.

In terms of valve clearance for the VTR with uprated turbo cam, you can contact catcams and see what the greatest lift value you can run on standard VTR pistons which will give you your limit for the forgies. The 4901216 turbo catcam for the roller type vtr head (which is what you probably have being a 90bhp silver top?) is fine with standard pistons, so unless you are going custom there shouldnt be a problem.

27th December 2009, 18:20

thanks for that mate, not that i dodnt turst your judgement

just wanted to be totally positive about it beofre i purchase, as said it would be a costly mistake on my behalf which would throw my build back months, but youve now cleared it up in pm so its all cool. havent decided on turbo cam yet but will most probs be hitting catcams up for a custom jobbie to which ill explaint the situation to them...sorted

27th December 2009, 18:30

It should be a pretty decent spec by the sounds of it when its finished

Just one other thing, maybe decide on what cam you're going for before fitting pistons just in case you go for something with big lift that requires a cutout which can be milled out.

27th December 2009, 18:35

will be mate as my lump is still in the car anyway, just going to leave it in till ive got evrything for the turbo side then build it all up in a day or two so its just done and done sort of thing, could poss do this mate....know a few engineers who could get it done for free anyway, was that exhaust loud? got near enough the same back box on my vtr but no silencer.
link to my progress thus far if your interested:
http://www.saxperience.com/forum/sho...d.php?t=255661

27th December 2009, 20:02

Looks well so far. The exhaust sounds good, not over loud or annoying.

27th December 2009, 21:09

thanks mate,its coming along

27th December 2009, 22:02

it will work, we're using jp4 pistons in a vtr block in a engine we're building,
but due to being a 8v and a high spec cam we're having them pocketed to suit.

if jp4's will work, im 100% sure j4 will too

27th December 2009, 22:04

sounds good dude, saving me a few pennies not buying new...forking a lump of money out at this point in the year isnt what i had planned...but need must for a bargain