Fuel injection rebuild

[Simmy]

And just to ensure that progress is still slowly ticking over, here are some of the the cylinders and pushrod tubes, cleaned, painted and ready to go!



Just wondered about the ring gaps... They seem a little wide for 90.5s? Also noted a slight taper toward the base of the cylinder which widened the gap by about 0.05mm (i.e. on feeler guage leaf size up). Is this normal? Figured it's to counteract differential thermal expansion caused by the temp difference between head and base.

[Simmy]

In between some surgery and the inconvenience of crutches, I managed to pull the oil gallery plugs. Will hopefully be able to get the brass plugs and NPT taps I need when I am able to drive again.



I left in the one which extends to the no 4 bearing as I believe it was specifically designed to also restrict oil flow.
Also decided that brass would be ok since it has a very similar expansion coefficient to ally. It's also just easier to get hold of.

I also took measurements to see if I could extend the oil gallery in the right side of the case, and it seems ok, with about 1mm of case material on either side of the gallery hole. Just needed to find a very long do still bit to do it... It's going to be nerve wracking when I get there.

[Wentzel]

Looking good!

I went through that process recently and was also stressed up but it worked out pretty good.

You can try engineering supply shops for the 250x6mm drill or similar size. If you were closer you could borrow mine.

[fourier]

The engine build is coming along nicely!

You should be able to replace the #4 bearing gallery plug without issue.

The aluminium cases (as you appear to have), do not have the restrictor plug, as is found in the magnesium cases. I have removed this plug on two of my alli cases, and found that it was just a standard plug, like the rest that were removed.

The actual oil restriction to the #4 bearing, is a tiny 2mm oil feed hole, as found in later main bearing shells. Unfortunately I no longer have an earlier design #4 bearing to measure what the oil feed size was reduced from. The size of the oil feed hole in #4 bearing shell, was probably reduced at the introduction of aluminium cases, due to no restrictor plug being present. This 2mm hole provides 3.14 sq mm of flow area, as opposed to the 7.228 sq mm provided by the stepped restrictor plug (5.4mm pin in a 6.2mm oil gallery).

You can also look into getting aluminium gallery plugs. I have used FTF alli plugs without issue.

[Simmy]

That's great info to have! I will wait for the set of bearings just to be sure, before I make the final call on it.

I did see that FTF has these plugs, but I am struggling to get them to get back to me. I also torn or whether to just but the bullet on their fittings, or just settle for brass barbs (which should be cheaper, but I have been surprised how pricey the hydraulic fittings are). But I figured I would be doing it on the basis of engine "bling" than for any other reasonable cause.

And thanks for the offer Wentzel. I am not to too phased by buying the bit. It's the set of taps that scare me looks like they are about R500 per tap, and it looks like you need both tapered and bottoming. In fact, the taps could cost more than the entire set of FTF fittings!

[Riaan.N]

Have you contacted Somta or you can buy via BMG. Somta has a cheaper line of products which should be fine if its only going to be used just a few times...what I’m not sure about is if the actual thread and type of tap will be available in the cheaper range.

Another alternative is to contact Tool & Allied, but supposedly the Jhb branch is the best one, the Centurion one is not to my liking.

[Simmy]

Thanks for the advice! I suspect I might get lucky with the larger taps. I believe the 1/16th is always a little tricky to source.

Thankfully, I am stuck at home, so I can do a little research

[fourier]

The taps are quite expensive, but be sure to also buy the correct size drill bit to suit the tap. I found no reason to buy anything more than three NPT taps (no "bottoming" taps required). If I recall, I bought a 3/8", an 1/4", and an 1/8" NPT tap.

Take it slow when tapping the plug threads. Regularly test the plug depth. Leave about one thread protruding when the plug starts to tighten. When the plug is fully tightened, it should be flush with the case. It is easy to cut the thread too deep, which could obstruct interlinked oil passages.

[Wentzel]

I will be watching closely as I have to do the galleys also. Let us know where you find the taps and plugs and how it turns out.

Usually I try to buy the tools to have them for next time but sometimes it gets a bit pricey.

[Simmy]

So after looking around, it seems the tooling required is indeed a 1/8, 1/4 and 3/8 tap. The 1/16 is not necessary if you enlarge the holes slightly to 1/8 (the imperial system makes no sense to me... 1/8 should be twice the size of 1/16, but its not?). And I managed to get hold of the guys at FTF, so I will go with the pricier ally fittings for the oil system. Its probably worth while in the long run.

The tooling can all be sourced from Tool and Allied, as suggested, including the 250mm bit. I will try and get those next week. Seems like the bottoming taps aren't required, so I will go with plug/second taps, which should be a fair compromise. And since I need to do it on 2 cases, it kinda makes sense.

So thanks all for the input!

Whilst trying to sort out the AN fittings for the oil system, I started wondering about the fuel side... I am pondering using the newly installed fuel pump and regulator instead of the mechanical pump. Reason being that I would like to test the electric fuel pump, and save me from having to replace the mechanical pump flange which is broken. Just worried that the pressure will be too high for the stock carb. Volkspares wasnt terribly helpful in being able to tell me what the minimum pressure setting is, but I think is 5psi. Unfortunately there is very little by way of specification for the part online:
https://www.c-f-m.com/performanceparts/ ... -p2156.htm

Do you think its worth the risk of assuming it will be fine, or should I just play it safe and go stock whilst I run the engine in?

[Tony Z]

stock fuel line will be fine for your power.
I use the 3.5psi CB performance fuel pump on my weber carbs, in all applications, from stock to stroker. I run the same pump in my bus and Angrrr without any issues. You'll need something higher pressure for FI - go to Diesel Electric and get a Bosch 044 fuel pump and never worry about the pump again.

[Simmy]

Well, the fuel pump, regulator and fuel lines are in already for the FI installation later. Its just a question of whether to make use of them now or later.
My concern is the fact that it will be too high a pressure for the carb even with the regulator set to its minimum threshold.

[Wentzel]

If you need a anything for FI you can have a look at fuel performance's website they have a lot of pumps injectors etc. I bought a bosch 044 equivalent from them and so far no issues.

I misread you already have it installed but maybe for
future reference then.

[Simmy]

It looks like i will need to go back to the stock fuel pump. The electric pump is from a Mk2 golf, which means is rated for 5-6bar, and I think the regulator can only reduce this to something in the range of 30psi (the SMax regulator I have has no datasheet or online info, so I am basing this on similar units with similar HP ratings and sizing).

That basically means that its about 10x higher than necessary, which will either leak out the carb or cause it to run hopelessly rich. I dont think its worth the trouble of experimenting. So I will go ahead with the FTF oil fittings and update you all when I have plugged a few of the galleries.

[Simmy]

Another delayed update...
Finally got all of the tooling to do the oil gallery plugs and the extension of the oil gallery as per the HVX mods.

For those thinking about doing the same, here is what I found:

• The taps are difficult to find, and generally pricy if you do, but toolcentre.co.za keeps them all and they aren't too expensive

• You can get away with leaving out the 1/16th size for the 6mm plugs. Just go for the 1/8th

• Buy extra ally plugs... I destroyed two in the process, but bought another set for another mag case.

• the 12mm plugs were really tricky for some reason. I think it's because you are supposed to work with an 11.1mm hole, but it's pre-drilled at 12mm. So I think what happened was the tap shifted slightly every time I pulled it out to check, and that caused the threads to get cut slightly strange. As a result I got caught out by some galling and then stripped a socket. It also helped to run a steel plug through to prep the thread before the ally went in. The other plugs were really no issue.

• you need to tap pretty deep to get the plugs to seat (almost the entire tap length), which means a lot of drilling. So checking that it wouldn't break through anywhere was key.

• use a hand drill to do everything, and do it at high speed to avoid it biting. Holding the case upright, tight and straight was just impossible on my drill press, but was ok if you take it slowly with the hand drill

• also... They look great when finished

The pump plug didn't seat all the way, so I just ground it down to fit... This was the start of the woes I had with these plugs.


The first plug trashed. The second needed an easy-out to fix, then every thing came together after using a steel plug first.


The pump and it's bling. I did match and smooth the inlet port, open up a little at the lower gear, lap the face and smooth and polish the outlet too.


The final outcome. Also needed to clearance around the filter return to accommodate the AN adaptor.


I am going to need to clearance the tinware, but the case itself demanded that anyway.

I also redid the breathing mods you can see in the port between the cylinders and at the top of the case. I also plan on adding an extra breather port, like you can see in the second photo, but between the webbing inside the case. Reason being for this is that I figure all that displaced air gas to make it all the way through the case first, so why not deal with it at source... And also can save the effort for some bigger build in the distant future.





All of the followers had three oil grooves ground in the jig in the background, and then polished with a blue silicon wheel so there are no burrs at all.


No photos of the oil gallery extension unfortunately. Doesn't really look like much anyway.