Intake Cam For Mi16 Xu10J4R Hybrid?

[xy8 4]

Short specs of the engine ,

 

j4r block , mi crank , j4r rods and skimmed pistons, -0,6mm , 0.2 mm above the deck .

 

mi16 head, 1.2 mm head gasket , 2045cc, cr 10.6 - 10.8

 

Valve reliefs have been deepened ,but still intake has only 3.5 mm total clearance TDC.

 

STD mi16 intake and management , 255 cc injectors .

 

AFR needs to be adjusted with wide band lambda, runs maybe little bit rich .

 

STD cams on 2 . 2 pulleys

 

It´s built on a budget , I used parts I had , as temporary solution after mi16 threw a rod , turns out it´s not that bad , engine still in one piece after 6 month.

 

It goes well , has some torque but doesn´t rev to the redline as easily as 1.9 mi16, after 6300 it´s over.

 

 

 

Cam regrinds can be made locally , but I am not sure about the profile.

 

Any ideas.

[petert 586]

If 3.5mm is total clearance then you have little option other to run std cams.

 

ie

3.5 - 2.2 (safe valve to piston clearance) = 1.3mm lift at TDC

 

A standard cam with a #3 pulley has 1.3mm lift at TDC.

[xy8 4]

Probably not the best option, but will it work with something similar to stage I cam , retarded just enough to clear the pistons.

[petert 586]

You need something with 215-220 deg @ 0.050". ie same as Mi16. My Stage I cam, which has 226 deg. @ 0.050", will be too big. No point in retarding it just to make it fit.

[welshpug 1,657]

on a budget, best bet is some standard XU10J4 pistons, monster valve cutouts.

[petert 586]

then he'll need XU10J4 rods as well.

[xy8 4]

Xu10j4 is not an option , impossible to find here , I tried .

 

 

Ok , I am not going to bother with cams , not much to gain anyway at current state.

 

 

Thanks,

[welshpug 1,657]

is postage too expensive to bother?

[xy8 4]

is postage too expensive to bother?

 

It depends , what you have in mind.

[petert 586]

I'd sell you a set of rods and pistons for AUS$60 + postage.

 

However, how did you measure the total clearance? The most accurate method is to drop a valve onto the piston (no seal, spring, retainer etc. on the valve), whilst the piston is at 6 deg ATDC.

[xy8 4]

I'd sell you a set of rods and pistons for AUS$60 + postage.

 

However, how did you measure the total clearance? The most accurate method is to drop a valve onto the piston (no seal, spring, retainer etc. on the valve), whilst the piston is at 6 deg ATDC.

 

 

I measured like that at TDC , just found notes I made , it was actually 3.9 mm for intake , didn´t measure 6 degrees ATDC .

[petert 586]

It gets closer after TDC by approx. 0.010" on an XU10J4.

 

3.9mm will be just enough for a slightly bigger cam.

[xy8 4]

I'd sell you a set of rods and pistons for AUS$60 + postage.

 

However, how did you measure the total clearance? The most accurate method is to drop a valve onto the piston (no seal, spring, retainer etc. on the valve), whilst the piston is at 6 deg ATDC.

40 euros for pistons and rods sounds good , any idea how much postage will be.

 

I have been thinking about using modified 87 mm fiat pistons( 0093202 mahle ), I can get 4 new pistons with rings for 140 eur.

22 mm pin , 34.17 mm compression height.

[petert 586]

XU10J4 is 39.1 comp height and 23mm pin.

[xy8 4]

I have xu10j4r pistons and rods , compression height 33.8 mm now skimmed to 33.2 mm.

 

If I use j4r rods then fiat pistons can be modified to fit, maybe.