Guys can anyone recommend an engine builder that has had experience with FJ20 engines and would be keen to have a look at my engine while its open before i seal it back up with new gaskets etc...

I would rather pay the money now for someone to give it a good look, then pay the price later 5 seconds after starting it up and stuffing something up...

Namely when i crank it over by hand i can hear a small tiny crunch once on each revolution almost as if there is a piece of sand in there somewhere ... It doesnt seem right

Cheers

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If in Doubt ... Call Datsport

Hey Graham give Steve Thomas at Top Racing a call, he was the guy who built my DR's engine (tuff as, destroyed my gearbox ). Steve has had plenty of experience with FJ's. He was once the owner/proprietor of SST. Now I know some will say less than flattering things about him but he DOES know FJ's.

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Vaughan
'70 P130 Super 6
Fiesta XR4 (modified)
Formally: 510 L22B twin webber terror
510 FJ20et (510 FJ)

Well, I don't know what your level of expertise is with these engines so forgive me If I'm telling you how to suck eggs

A classic problem with the FJ20, especially when cranked over by hand or even with the starter, is a lack of engine oil pressure.
This results in zero tension on the upper cam chain.
That allows the intake and exhaust cams to "jump" as the valve spring pressures are applied to them.
Also, the upper chain clatters against the front cover and the cam cover guides while all this is going on.
Trust me, it sounds AWFUL and I wouldn't have bought my engine if I had heard this racket when turning it over
If you haven't done this modification already, I advise you to consider it.
It really does make the engine sound a LOT better at startup and removes the possibility of that initial wear.
This is a well documented problem and there is a simple remedy, a Mazda/Ford chain tensioner that utilises a ratchet plunger in addition to engine oil pressure
Let me know if you need any more info. I think I have a spare tensioner around somwhere

_________________
Regards, Graeme
Just trying to help...
http://nissanman.shutterfly.com/
graemes@internode.on.net

Thanx alot for your help guys..

First thing yes i will be taking my engine to your referal, cheers vaughn

Nissanman, thanx also for your input, i may have to turn over my engine again and see if it is the chain noise.. even still i am very interested in the mazda ratchet tensioner...

How about just a part number , then i could just order it from mazda direct and plus it is new

Have you got a step by step guide there buddy.. i heard it's not that hard!

_________________
If in Doubt ... Call Datsport

I'll get a bit of info. together for you.
Take off the inspection plate on the front of the head, the one that is oval shaped and says "FJ20".
Behind that is the offending chain tensioner.
Also take off the cam cover.
Watch happens when you rotate the crank

_________________
Regards, Graeme
Just trying to help...
http://nissanman.shutterfly.com/
graemes@internode.on.net

Hey Graham I have done mod to my eng and works well I'll try and find out the part # for you.

Dead easy mod to do however there is one thing you need to do that people forget to tell about. You'll need to remove the rubber block from the end of the new tensioner. The easy way to this place the shaft in an open (loose) vice and hit with a drift the shaft out of the rubber block then clean off any excess rubber of the end. Then put it together and install as per normal.

Another tip I've recently bean told about is non return oil filter which helps keep oil in th engine and filter. I haven't tried this yet but will next service.

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Regards
DEZA
OzDat WA President

76 180B Wagon FJ20e, LT8 -daily
83 DR30RS FJ20et, GT35/40, 45mm Turbo Smart waste gate, 35mm Sard BOV, 356rwhp @ 19psi.

GO HARD or GO HOME, GO SIDEWAYS or GO SQUARE

The P/N is 3953-12-500A for a Mazda 323 I believe
Compare the Mazda part carefully with the original Nissan tensioner and you will see the changes necessary.
Rubber foot to be removed, and slight profiling required to open up the oil passage to line up with the FJ20 oil supply
Pics. are from a posting on FJ20.com, there is quite a discussion on there about this little sucker

_________________
Regards, Graeme
Just trying to help...
http://nissanman.shutterfly.com/
graemes@internode.on.net

Thanx guys i really appreciate your prompt and detailed replys..

Should be easy enough to go and do this modification without any hassles.. as soon as the part comes in..

Cheers

_________________
If in Doubt ... Call Datsport

Here are some pics on how to convert the Mazda P/N 3953-12-500A to replace the OEM cam chain tensioner A: -

Cam Tensioner A is located behind the "FJ20" inspection plate on the cylinder head.
It pushes against the chain guide to take up the slack in the cam chain.

This is the Mazda oil pressure fed ratchet chain tensioner as it is out of the box.

Drill a 4mm hole through the rubbing block directly opposite the plunger.

Insert a punch of the appropriate diam. into the hole. I used a broken drill bit.

Tap the punch firmly while the rubbing block is resting on the jaws of a vice.
The plunger is a press fit into the plate and is also bonded to the rubbing block.
It will come away fairly easily after a few taps with a hammer.

Clean the rubbing block material off the end of the plunger, trim the spring to 52mm and the tensioner is good to go.
NOTE.
The bottom of the casting should be no thicker than 4mm or it will foul on the FJ20 head casting.
Depending on the unit, you may need to grind off some casting on the head mating surface to avoid the problem.

Here is the FJ20 paper gasket overlaid on the rear of the Mazda tensioner body.
You can see that the oil feed hole is still within the gasket cutout which is satisfactory.
I bought my tensioner [pre-modified] years ago and it has been functioning fine with the gasket as pictured.

The OEM tensioner is a plunger type and the end of the plunger applies pressure to the Chain Guide B.

This chain guide has a neoprene pad on it for the plunger to bear on.

Cam Chain Tensioner B is a plunger with rubbing block.

This shows the cam drive in detail.

Anyhoo, I made up an aluminium template to use for the tensioner block modification and gasket size.
The oil feed hole in the gasket is elongated to allow the engine oil from the block oil passage to match the Mazda block oil feed hole.
The two feeds actually overlap so there is adequate space for the oil to circulate.
You can see Block #1 has a wider groove cut in it to Block #2.
There is a variation inherent in the size of the castings since this is not a critical dimension in the Mazda application.
Once you overlay the template you scribe a line where the base needs to be notched and use a 90deg cutting tip in a die grinder to do the job

_________________
Regards, Graeme
Just trying to help...
http://nissanman.shutterfly.com/
graemes@internode.on.net