Hi,

I'm rebuilding the engine from a 2004 Streetwise and was wondering what the best options are.
Should I put the N-Series HG, oil rail and uprated bolts, or this doesn't fit the 1.4 engine?
Is it better to use the aluminium inlet manifold, or it will not fit the car (can I use the same throttle body with the aluminium manifold)?
Can the block be skimmed (suppose not because of the liners and the fact they need to protrude about 0.05mm above the block)?
What is the best thermostat to use (the PRT from the freelander or another one?)

A lot of questions I know but as I'm doing it I would prefer to do it only once...

Ricardo

Set the liners 4 thou above engine block, fit a grey PRT thermostat and use the SAIC 6 layer HG kit and you'll never need to worry about the HG again.

Thanks John,

Does fitting the SAIC HG mean fitting uprated bolts and oil rail, or can it be mounted with standard bolts and oil rail?
As I have all the engine disassembled and liners out, I'm wondering if the liners need glue or something else to seal on the bottom?

Ricardo

Definitely use the uprated oil rail but I've used it will standard bolts and torque settings with no problems. A lot of suppliers say they are the 10.9 grade bolts are to be honest over than the set I got from the MG dealer NONE others have ever had 10.9 stamped onto the head

I would agree with using the SAIC/N series six layer gasket, especially as you have the liners out (I assume that either they were OK for stand-proud or that you are fitting the shim kit to get them to an acceptable position). Plenty of people have fitted the 6-layer MLS with the original oil rail and 9.8 bolts and had no further problems, but I would certainly fit the stiffer oil rail. I would fit the 10.9 bolts too (even the genuine MG Rover bolts are not marked 10.9, but then the original bolts were never actually stamped 9.8 either ) It's up to you how far you want to go, but if you use the higher tensile bolts, note the revised tightening sequence of 20Nm + 180 degrees + 135 degrees).

When refitting the liners, they need a bead of Hylomar Blue around the shoulder to ensure a seal. You will need an anaerobic sealant for the oil rail/bearing ladder interface, the sump/block and the cam carrier/head. Loctite 574 is the one that has most often been recommended. Avoid using silicone/RTV - I still see some numpties recommending this, but it is wholly unsuitable.

Where I will disagree a little with John is over the fitting of the pressure relief thermostat - I think it is an unnecessary extra expense as there has never been a shred of actual evidence that this makes any useful difference to the HGF problems. Certainly it didn't in the Freelander (which was where it was first used), and didn't appear to make any difference to the incidence of HGF in either the Rover 75/MG ZT or the MG TF which were the only MG Rover cars to which it was factory fitted. It is your choice, fit one if you wish, but don't fret about it being essential to do so - based on the experience with my ZR which had the SAIC/N series gasket fitted (along with the rail and 10.9 bolts) and left with the standard thermostat in 2013 and has covered over 75k miles since without any issues.

Theoretically the block could be skimmed, but there isn't much point - if the liners are low there is a shim kit available to raise them (easy job as you already have them out anyway).

I wouldn't worry about fitting an alloy inlet manifold either - just make sure you use the up-to-date black viton inlet manifold gasket (part number LKJ101110); it is slighly thicker and more robust than the older green IMG and I have not heard of anyone having IMG leakage with one of these fitted. I would avoid the green ones like the plague, especially the cheap aftermarket ones as some of them are really quite thin and are destined to fail (probably sooner rather than later).

Good luck with the rebuild

Thanks for the feedback Evil C.

I had the head skimmed and should be ok (the metal seems quite porous though with lots of black spots in the shining new surface - suppose this is due to casting).
Regarding the thermostat, someone removed it from the car (they left just the original casing empty...) so I need to refit one anyway.
As for the block the liners are not far from the 0.1mm above the block (I believe this is the correct measure?) and I need the block filled in one end (it has a small dent on the surface) so will ask the machine shop to leave the liners 0.1mm above the head.
If I find an aluminum manifold will install it, otherwise will leave it for later.

Ricardo

I own a 214 [R8] with the alloy inlet manifold, the throttle body and stepper motor differ from the plastic manifold I believe?

A decent engine rebuilder will be able to pressure test the cylinder head coolant passages; if there are voids in the head surface exposed by a skim, the head is suspect. There is a minimum head height after machine work quoted in the manual.

If the block face isn't flat and the head is suspect I would consider looking for a salvage engine?

The liner stand proud height's need to be exact and uniform to use the MLS kit, otherwise people recommend a improved silicone bead gasket from Discount MG Rover Spares down on the South coast.

I should add that once sorted they fly! Mine flew up the motorway a month ago and still wanted to accelerate from 70mph with ease. I remember the salesman at the local Rover dealership telling me that the Rover K Series engine was the better of the two [between a 214 & 216]

Ricky_M wrote: ↑Mon Jun 16, 2025 9:11 am Thanks for the feedback Evil C.

I had the head skimmed and should be ok (the metal seems quite porous though with lots of black spots in the shining new surface - suppose this is due to casting).
Regarding the thermostat, someone removed it from the car (they left just the original casing empty...) so I need to refit one anyway.
As for the block the liners are not far from the 0.1mm above the block (I believe this is the correct measure?) and I need the block filled in one end (it has a small dent on the surface) so will ask the machine shop to leave the liners 0.1mm above the head.
If I find an aluminum manifold will install it, otherwise will leave it for later.

Ricardo

The plastic manifold are OK especially with a metal throttle body , I would stay away from ally inlet especially the early model because that as a stepper motor on and your wiring and ecu would need to be changed , a good plastic inlet with jiggle valve still in will work fine .

961tat wrote: ↑Fri Jun 20, 2025 10:03 pm
The plastic manifold are OK especially with a metal throttle body , I would stay away from ally inlet especially the early model because that as a stepper motor on and your wiring and ecu would need to be changed , a good plastic inlet with jiggle valve still in will work fine .

Agreed. Daft to remove the jiggle value, its there for a purpose. Many do remove it though. Nothing wrong with the plastic manifold

While it's all apart it's important to inspect/replace the steel coolant pipe that runs under the manifold; these come in 'patterns various' depending on your application, but others can be fitted.

I wouldn't reuse the old thermostat housing, but buy a new assembly complete. There may be a choice of different thermostat opening temps.

Because the later damp liner engines have an open top block, liner protrusion is critical and must be identical to use the MLS gasket. Any doubt about this talk to Discount MG Rover Spares.

Assuming the engine is being rebuilt on a stand it might be worth just fitting the crank with its bearings/assembly paste without rods and pistons. Then rotating the crank to check for tight spots. If there are tight spots that will introduce additional vibrations into the block and increase the possibility of head shuffle.