4g54 on carbs

[Paulvdsterren]

Hey guys,

question for the pro's out there. I have a 4g54 Montero currently equipped with a 32/36 weber carb. I live on curacao (small island in the carribean) and went on holiday to Sydnet were I bought myself a 1995 magna TR cyclinder head with roller rockers and hydraulics. Now for the questions:

- according to many sources the cyclinder should fit, do you concur?

- what do you recommend twin weber carb or 4 motorcycle mikuni of keihin carbs? (not going efi) and if so any idea were I can buy a twin intake manifold?

- finally would the Montero fuel pump by sufficient for the hydraulics of the magna cyclinder head?

- should I buy a balance shaft eliminator kit?

I hope you guys have some ideas!

Thank for your help.

Paul

ps: I don't plan to go turbo

[BAD-SIG]

The head will fit but depending on what pistons you have the compression ratio will be either too high or too low. Please post a photo of your pistons (or at least the rocker cover) and more info on your vehicle like year and model (or the car the engine came from originally if it was originally from another car). The intake manifold should fit and so should the exhaust one. The Montero is known here in Australia as a Pajero.

You'll notice with the Magna head that it has a pulley that runs the water pump on a FWD Magna, which will hit the firewall on your Montero. You can remove the pulley but part of the camshaft will still stick out of the back of the head. As long as you use a new rear camshaft seal, it shouldn't leak oil from there, otherwise you will have to take the camshaft to someone to cut a bit off the rear end (so it's the same length as the Montero's stock one) and swap over and fit the end caps off the valvetrain including the sealing cap.

As far as I know, the naturally aspirated Astron 2.6 engines came in compression ratios of 8.2:1 (old Astron 1 series with the flatter rocker cover), 8.8:1 (which should be what your Montero was original) or 9.3:1 (on the later model Magnas with roller rockers). You should be ok with your combination of Montero block and pistons and roller rocker Magna head, you should end up with the magical (and better) 9.3:1 compression ratio.

With the slightly higher compression ratio and roller rockers, the engine should be more efficient (slightly more power and torque plus better fuel economy) and more elastic, revving easier with a slightly higher maximum rpm.

Also, you cannot use a mechanical fuel pump with the Magna roller rocker head as the Magna camshaft has no lobe to operate the mechanical pump. You will need an electric fuel pump.

And as for the balance shaft elimination kit, here's what it will do:

-remove about 4 kilos of weight off the engine
-make engine rev quicker and more free
-car will make about 2hp more at the wheels as there is less rotating mass for the engine to spin (similar to lightening a flywheel)
-engine will vibrate a little more, mine seems to vibrate more only between 3500 and 4000 rpm
-the balance shafts bearings and chain that runs the balance shafts can be a source of engine failures, so by removing them you remove the chance of these parts failing (there will still be a smaller chain, but it won't be a weak point anymore)