HIF44/HIF6 manifold to carb spacer

[listerjp2]

Hi

I have fitted a HIF6 carb to a mg metro manifold on my 1300 marina engine.

All looks good but when I fit the bonnet it touches the top of the dashpot.

I don't want to put a bulge in the bonnet as I would like to keep the clean lines.

The carb came with a plastic spacer around 1cm thick which is between the manifold and the heat shield, if this was cut at an angle it would allow the carb to have less of an angle upwards thus allowing the carb to fit under the standard bonnet.

Can I do this or does the thickness of the spacer have something to do with the airflow?

Adrian

[Robert in Cumbria]

Re: HIF44/HIF6 manifold to carb spacer

The spacer may play a tiny part in the airflow characteristics of the manifold but more of a concern is the thermal insulation between the inlet manifold and the carb, as mentioned in another thread, the modern fuels we are blessed with are more evaporative than the ones we used to get. Airlocks and vaporisation are going to become a headache with these engines, reducing the plastic spacer will make this worse. Is there any scope to shift the engine sideways or tilt it by adjusting or re drilling the engine mountings? It may sound a bit drastic but the mountings I have are intentionally designed with a bit of flexibility for this type of reason.

Another suggestion... Machine the head-manifold face of the manifold at an angle? or machine the carb mounting flange face of the manifold, or both? I would steer clear of reducing that thermal insulation plastic spacer.


I have re-posted my reply to this thread, I hadn't realised there were two identical threads The mods may wish to delete one or the other to avoid confusion?

[listerjp2]

Re: HIF44/HIF6 manifold to carb spacer

Hi Robert

I thought it may be the case.

Maybe the next question to all, can I tilt the engine slightly to the right by putting a spacer on the left hand engine mount, I only need around 1cm to clear the bonnet?

If so then that would be the easiest way out of my predicament.

Adrian

[Robert in Cumbria]

Re: HIF44/HIF6 manifold to carb spacer

Hi Adrian, I take it this is a Mk2 Marina based Roadster? If so I would slot the holes in the chassis bracket to lower the engine, if the mounts are like the ones on my Mk2. I don't see any place to put spacers with the setup I have/had which would tilt the engine.

Support the engine and remove the entire engine mount, then slot the holes in the chassis brackets with a Dremmel, or use an angle drill to drill two new holes a bit lower. Alt. slot the holes in the actual rubber engine mounting where they attach to the engine side brackets or a bit of both? I wouldn't touch the holes which attach the brackets to the engine, the brackets are not the heaviest I have seen and could crack up if you slot those holes. Both my brackets have been welded up because of cracking. In fact I need new ones.

The bottom of the sump on my Mk2 was 88mm below the bottom of the chassis, if you aren't going 'off roading' then you can probably afford 10mm less ground clearance?

As for tilting the engine, I have never seen a level road, we go round corners and up/down hills no worries? Tilting the engine ('A' series) to the n/s should be less of a concern than to the o/s because the oil drains down from the head via the push rod holes which are at the n/s. You may have to make a small allowance for the oil level when reading the dipstick? Again, I suggest not critical.

Bob's Marlin n:s engine mount.jpg

I have attached a pic of my (VERY rusty) Mk2 mount.

The red arrows showing the holes I would not slot, the green arrows the holes I would slot and having looked at the pix, I think I would slot the holes in the loose part, not the chassis side bracket, easier to revert to standard that way. The blue arrow is where there should be another bolt, but I think there rarely is, that would be a wise thing to fit if you do slot the mounting holes and place a spacer in the gap that would result from lowering the engine (say a 3/8" UNF nut?).

[listerjp2]

Re: HIF44/HIF6 manifold to carb spacer

Hi Robert

Many thanks for your time on this.

Yes it is a MK2 and Marina based.

You are obviously busy with getting your own motor up an running.

Adrian

[listerjp2]

Re: HIF44/HIF6 manifold to carb spacer

Hi Robert

Heres a picture of my engine mounts.

Now, the fixture to the chassis has a plate welded to it with a thread cut into it where two bolts screw in.

001.jpg

I hope you can see this.

Adrian

[Robert in Cumbria]

Re: HIF44/HIF6 manifold to carb spacer

Ok, that's what I had, if you re-drill the lose plate between the chassis and the rubber mounting, it's a done deal.

I have made a larger bracket on the chassis which gives me more scope for relocating, both vertically and fore-aft.

Marlin engine.jpg

[listerjp2]

Re: HIF44/HIF6 manifold to carb spacer

Once again Robert many thanks.

They say a picture says a thousand words and I have now spotted your gearbox support, can I have a picture of that also.

Last one honest.

Adrian

[dogoncrazy]

Re: HIF44/HIF6 manifold to carb spacer

Adrian
I did this as a conversion to my Roadster [Carb/MG metro manifold] and to be honest cannot remember having any issues with clearance so I'm rather confused as to why there should be with yours.I'll see if I have any old photo's that may shed light on any differences.

[listerjp2]

Re: HIF44/HIF6 manifold to carb spacer

Hiya

That would be helpful, thanks.

Adrian

[Robert in Cumbria]

Re: HIF44/HIF6 manifold to carb spacer

Here you are...

The mounting is carved from 5mm ms plate salvaged from a skip at a fabrication shop. Used a 9" angle grinder to rough cut to shape and a 4" flap wheel to finish. The inrigger brackets are 80 x 40 box with 4mm wall. The rubber mounts are Marina rear spring eye bushes, narrowed to 40mm and the inner tube to 50mm. The bolts are the original 7/16" UNF spring eye bolts.

I made the yolk and brackets from cardboard first, then drew round them onto the steel. The speedo connection was tight to get around.

The bracket is angled, I raised the engine at the front, so that it's tilting back quite a bit. So it slides over the rocks easier!!!

Gearbox rear mount (front).jpg

Sorry about the noise... It must have been nearly dark.

Gearbox rear mount bare.jpg

[listerjp2]

Re: HIF44/HIF6 manifold to carb spacer

Wow, now i am well impressed!

Thats not going to move in a hurry.

Can you still get to the speedo connection?

Adrian

[Robert in Cumbria]

Re: HIF44/HIF6 manifold to carb spacer

Thanks, yes it's strong and robust.

I have attached the speedo cable, but I am not sure if I am going to use the angle drive or not. It depends what head I use and how I construct the gearbox cover, I haven't looked at speedo cable routes yet.

[dogoncrazy]

Re: HIF44/HIF6 manifold to carb spacer

adrian
have been through my CD files with no success on finding any pictures that may have helped. Do you have photo of your install as it may stir the memory?

[FranklinLeicester]

Re: HIF44/HIF6 manifold to carb spacer

Hi Adrian, Some time ago I had a notion to upgrade my carb to an HIF from the Metro range. Never got round to it but I remember the dealer in 2nd hand SUs telling me that the HIF 38 was the best to use for a standard un- modded 1275cc engine. He said the HIF44 was too big a bore for my application. I'm not sure how your HIF6 fits with these sizes. One thing I do remember him saying was "watch your bonnet space, the HIF is taller". OK you now know that. I would carve the plastic spacer and see how you go, it'll cost you nowt and will probably be OK. Also, if you tilt or lower the engine this will mean you'll have to modify the exhaust front pipe as it will no doubt foul the gap between the chassis and the inner wing. I hope you get it sorted and let us know if you detect any perfomance and MPG improvement. Franklin.