Restoration-Mini

Technical Forums => Maintenance and Modifications => Topic started by: tmsmini on November 09, 2019, 09:08:11 AM

Title: HIF Manifolds
Post by: tmsmini on November 09, 2019, 09:08:11 AM
While sorting through some manifolds, I saw a difference in the current MS C-AHT770 compared to the older CAM6618.

https://www.7ent.com/products/intake-manifold-single-su-hif-used-cam6618-used.html (https://www.7ent.com/products/intake-manifold-single-su-hif-used-cam6618-used.html)

If anyone is running into clearance issues, the older manifold might work. The new versions flow better, but if they don't fit, they don't work either.
I just reinstalled the newer manifold and I did not measure the difference before hand, so I am not sure of the exact difference.

It looks like most CAM6618 are pretty well used from looking on EBAY. Someone had cut the heater hose pipes off of mine.
Is there any way to repair those? Can you thread in an NPT hose barb?
Title: Re: HIF Manifolds
Post by: Jimini II on November 09, 2019, 09:20:57 AM
I have heard that the MG Metro intakes also have no clearance issues.
Title: Re: HIF Manifolds
Post by: MiniDave on November 09, 2019, 09:30:14 AM
Wow, that's a significant difference!

I'd think Metro intakes would be fairly the on the ground in the US since they ever imported them here.....

I'm pretty sure those hose ends are just pressed into the manifold - but I don't know this for a fact. I would see if you can knock one out from the other side with a long drift. If you can then either press in a new one or as you said, thread it for a hose barb.
Title: Re: HIF Manifolds
Post by: 94touring on November 09, 2019, 10:13:21 AM
Any idea what the size of the ports are on each?  Minus the centering ring part on the old. 
Title: Re: HIF Manifolds
Post by: tmsmini on November 09, 2019, 10:44:08 AM
I will get some measurements after I get things back together.
Title: Re: HIF Manifolds
Post by: 94touring on November 09, 2019, 10:53:12 AM
Cool thanks.  Also my understanding was the new manifolds have the spacer built in. 
Title: Re: HIF Manifolds
Post by: tmsmini on November 09, 2019, 11:41:45 AM
Looks like 32 mm on the old version and 35 mm on the new which would account for the lack of the locator rings on the new.
Now I need to measure my heads to see what matched up...
Title: Re: HIF Manifolds
Post by: tmsmini on November 09, 2019, 12:08:55 PM
Quote from: 94touring on November 09, 2019, 10:53:12 AM
Cool thanks.  Also my understanding was the new manifolds have the spacer built in.

That would make sense, but I never put 2+2 together.
Now I need to check the other car with the HIF on it to see which manifold it is as I am pretty sure I a have a spacer on it.
Title: Re: HIF Manifolds
Post by: 94touring on November 09, 2019, 01:14:36 PM
Spares use to make one of these with even bigger ports.  Though unless you have some monster race build, the velocity of the ports become an issue.  I've been thinking of testing a hif44 on my engine or going to a standard twin hs4 manifold to see if port sizing fixes some issues I have.
Title: Re: HIF Manifolds
Post by: 94touring on November 09, 2019, 06:00:11 PM
Used a flow calculator on those port sizes.  Plugging in a generic volume of fluid through a 1.75" carb feeding into two 1.26" (32mm) and two 1.37" (35mm) ports, the two 1.26" equals nearly the same volume as the 1.75" carb can supply.  The 1.37" ports would require nearly a 2 inch carb mouth to equal their volumes.  How much that effects power in a real world environment I'd need to see dyno comparisons.   Maybe vizardizing the carbs would work better on the larger manifold.  Shaving the lower edges of the carb piston and reducing the butterfly shaft diameter/cleaning up screws.
Title: Re: HIF Manifolds
Post by: tmsmini on November 09, 2019, 06:53:54 PM
I tried a 3/8 NPT tap on mine and the internal rust just crumbled. I think if the pipes were in good shape then 3/8 might work.
There is a small freeze plug that prevents getting a decent sized drift on the end. I suppose they could be drilled as well.
Someone on the Miniforum has shown how to replace the pipes on an SPi inlet manifold. As SPi inlet are NLA.
Title: Re: HIF Manifolds
Post by: tmsmini on November 18, 2019, 09:10:12 PM
I spoke to Jack at Seven when I picked up our engine. He said at one time Mini Spares did make a manifold that had longer runners. It was developed for 1380 and the use of the HIF44.
Now I need to go back and check the dimensions of the assorted manifolds I have.
Title: Re: HIF Manifolds
Post by: 94touring on December 01, 2019, 12:34:10 PM
Just fitted one to my 1275.  I needed a 6mm spacer between the manifold and carb so the linkages didn't foul.  Otherwise had no clearance issues. 
Title: Re: HIF Manifolds
Post by: MiniDave on December 01, 2019, 12:41:41 PM
Air cleaner can be difficult on these, the pancake, cone style K&N seems to work the best - it's biased up wards on the base plate, so the cone doesn't hit the bulkhead.
Title: Re: HIF Manifolds
Post by: 94touring on December 01, 2019, 03:54:21 PM
Going with the med stub stack and filter box.  Should fit just fine but the speedo cable may give it fits.  I wanted to go with a 45mm ram pipe but a filter won't fit without some major modifications.
Title: Re: HIF Manifolds
Post by: MiniDave on December 01, 2019, 04:49:23 PM
Heck, you don't need a speedo anyway!   77.gif

Best be careful tho, this time the cop radaring you at 90 mph might be right!  :D
Title: Re: HIF Manifolds
Post by: MPlayle on December 02, 2019, 01:20:41 AM
Depending upon the dash - one of the newer electronic speedometers?  Very accurate and no stiff, mechanical cable.

Title: Re: HIF Manifolds
Post by: 94touring on December 02, 2019, 06:55:14 AM
I think I'll be ok but what's the website for them?
Title: Re: HIF Manifolds
Post by: tmsmini on December 02, 2019, 10:35:22 AM
MiniSpares sell them, but I bought one from here:
https://www.digital-speedos.co.uk/gauges-c4/car-gauges-c28/smiths-m2/classic-british-mini-t40 (https://www.digital-speedos.co.uk/gauges-c4/car-gauges-c28/smiths-m2/classic-british-mini-t40)

There can be issues with the sensors as they modify them for the Mini. I am pretty sure Dean ended up buying a second sensor as the first did not fit well at all.
Being electronic, you need to pick your power source/supply care fully.
Title: Re: HIF Manifolds
Post by: MPlayle on December 02, 2019, 12:31:23 PM
I got the one for the Moke from the same place Dave linked.  I was first going to try with the sensor on the transmission, but the sender did not pulse correctly.  I could have received a free replacement, but I upgraded to the GPS based sender instead.  They credited me the cost of the old sender against the price of the GPS sender.

The GPS sender worked fine on the Moke.  I mounted it on the flat of the left front fender, up near the base of the firewall/bulkhead/windshield frame.

With the transmission mounted senders, you have to recalibrate them when changing tire sizes, but that is an easy process.  With the GPS sender, you set the calibration once and do not have to change it again.

Title: Re: HIF Manifolds
Post by: Jimini II on December 02, 2019, 04:43:21 PM
Quote from: tmsmini on November 09, 2019, 09:08:11 AM
While sorting through some manifolds, I saw a difference in the current MS C-AHT770 compared to the older CAM6618.

https://www.7ent.com/products/intake-manifold-single-su-hif-used-cam6618-used.html (https://www.7ent.com/products/intake-manifold-single-su-hif-used-cam6618-used.html)

If anyone is running into clearance issues, the older manifold might work. The new versions flow better, but if they don't fit, they don't work either.
I just reinstalled the newer manifold and I did not measure the difference before hand, so I am not sure of the exact difference.

It looks like most CAM6618 are pretty well used from looking on EBAY. Someone had cut the heater hose pipes off of mine.
Is there any way to repair those? Can you thread in an NPT hose barb?

The last one I did I did not use the ports for water (no need in Florida) but I did put the crankcase breather line through it as it tidied things up.
Title: Re: HIF Manifolds
Post by: Jimini II on December 02, 2019, 04:49:22 PM
Quote from: 94touring on December 01, 2019, 12:34:10 PM
Just fitted one to my 1275.  I needed a 6mm spacer between the manifold and carb so the linkages didn't foul.  Otherwise had no clearance issues.

The later production 1275 HIF carbed Mini's had the engine moved forward about 3/4" to 1" by moving the engine mount holes, this along with a longer engine stabilizer bar is how the factory made it work in the early 90's before the SPI came out complete with a full size dog dish air cleaner on top.
Title: Re: HIF Manifolds
Post by: 94touring on December 02, 2019, 04:59:24 PM
Quote from: Jimini II on December 02, 2019, 04:49:22 PM
Quote from: 94touring on December 01, 2019, 12:34:10 PM
Just fitted one to my 1275.  I needed a 6mm spacer between the manifold and carb so the linkages didn't foul.  Otherwise had no clearance issues.

The later production 1275 HIF carbed Mini's had the engine moved forward about 3/4" to 1" by moving the engine mount holes, this along with a longer engine stabilizer bar is how the factory made it work in the early 90's before the SPI came out complete with a full size dog dish air cleaner on top.

This is on a 74 that was originally fitted with a 998.  I do have the longer upper arm though.
Title: Re: HIF Manifolds
Post by: Jimini II on December 03, 2019, 05:15:24 PM
How did that affect the angle of the header?
I did one for a friend on a 1970 Clubman Estate who did not want to lift the engine to drill new engine mount holes.
I machined the spacer like yours and "tweaking" the throttle quadrant along with an adjustable stabilizer bar and shorter studs it worked fine but the lcb header which previously leaked sounded worse as it now faced further upward which the owner got sorted at the muffler shop and then traded for a VW Beetle convertible which is another story.
Title: Re: HIF Manifolds
Post by: 94touring on December 03, 2019, 05:26:18 PM
No header or exhaust issues to speak of.  Definitely no leaks in that area.
Title: Re: HIF Manifolds
Post by: 94touring on December 07, 2019, 10:24:48 AM
Fitment results.  Fits and fits well.  No room for error though!  Stub stack inside the filter turned the idle mixture from 14:1 to wouldn't stay running lean fyi.
Title: Re: HIF Manifolds
Post by: tmsmini on December 07, 2019, 10:51:02 AM
And that is with a 6 mm or 1/4 inch spacer? And no longer or adjustable dogbone?
Title: Re: HIF Manifolds
Post by: 94touring on December 07, 2019, 11:01:36 AM
6mm spacer gave just enough clearance for the linkages to not foul as well as the arm for the abutment plate.  I don't have an adjustable arm, just the fancy lightweight 1275 one that med or one of the blingy aftermarket people sells. 
Title: Re: HIF Manifolds
Post by: 94touring on December 07, 2019, 03:32:05 PM
One thing that would benefit this filter is a few extra gaskets or slim spacer so the tab for the filter doesn't clip the carb when you slide the piston off. 
Title: Re: HIF Manifolds
Post by: John Gervais on December 09, 2019, 05:20:00 PM
At one time, I cut an abutment plate (removed the side tab and below the holes) and used it as a thin spacer between the carb and manifold.
Title: Re: HIF Manifolds
Post by: CooperTune on December 26, 2019, 09:45:34 PM
I believe if you do some checking you will find the late cars moved the power unit 1/2 inch forward. Steve (CTR)
Title: Re: HIF Manifolds
Post by: LarryLebel on December 26, 2019, 10:35:05 PM
What's the cable for?
Title: Re: HIF Manifolds
Post by: CooperTune on December 31, 2019, 08:16:08 AM
On page one there is talk about replacing the water tubes in Metro HIF 44 intakes. The bore though the intake does not allow a drift to pass from one end to the other. The tubes are pressed in and are very tight. I saw off the ends flush with the intake, grind though the tube wall with a high speed burr. When the tube gets thin it will turn blue and can be peeled away with a sharpened punch. It takes time and and care. Once removed new tubes can be purchased at a good machine shop. They are used for intake by pass and heater outlets on common American engines. I mix up some 5 minute epoxy and press new ones in. I do run the water though even if it's not required. I also use a HIF 44 air horn and std plastic air cleaner with a K&N element. Top speed recorded by my GPS 96 MPH. Steve (CTR)
Title: Re: HIF Manifolds
Post by: MiniDave on December 31, 2019, 08:44:23 AM
I ran a stock air cleaner on Buzz too, it is SO much quieter than with a pancake filter and the like....doesn't look as cool tho  ;D

Larry, what cable are you referring to?
Title: Re: HIF Manifolds
Post by: tmsmini on January 04, 2020, 03:09:28 PM
I pulled my spare HIF out and looked at it, thinking I would use a smaller spacer, but on this MiniSpares manifold, the bracket and throttle quadrant will foul the manifold
Title: Re: HIF Manifolds
Post by: MiniDave on January 04, 2020, 03:26:07 PM
You could carve a little radius where the bracket is close to the manifold to make room for a smaller spacer....I think I ran a 1/4" spacer on Buzz.
Title: Re: HIF Manifolds
Post by: John Gervais on January 04, 2020, 03:38:46 PM
My current MiniSpares manifold required that I file a tiny (relief) amount off of the manifold itself where the throttle quadrant would have fouled.  This was with a 1/4" spacer.  I also filed a tiny amount off of the throttle quadrant itself. 

Of course, I could have simply used the thin spacer that I'd made from an old abutment plate as a supplement to the 1/4" spacer, or had a ½" spacer milled down...
Title: Re: HIF Manifolds
Post by: John Gervais on January 04, 2020, 03:50:36 PM
Another thing that I can't remember offhand - would it be possible to rotate the throttle quadrant 90° counter clockwise?
Title: Re: HIF Manifolds
Post by: Willie_B on January 04, 2020, 07:03:30 PM
Quote from: John Gervais on January 04, 2020, 03:50:36 PM
Another thing that I can't remember offhand - would it be possible to rotate the throttle quadrant 90° counter clockwise?

Not if you are using the stock air filter housing.
Title: Re: HIF Manifolds
Post by: John Gervais on January 04, 2020, 07:10:11 PM
Thanks - I'm using the stock air filter housing and I couldn't remember if I'd tried that at one time or another.
Title: Re: HIF Manifolds
Post by: tmsmini on January 22, 2020, 08:51:03 PM
So I finally got out a head and compared the older HIF manifold with some new MS versions.
It appears there is about 1/4 inch difference. Although I am not sure if my older manifold has been modified.

Not sure if you can tell how I was measuring. May not be scientific, but it convinced me that it might be worth trying at some point.

Not sure I trust myself to remove the heater pipes, so I will keep an eye out for one with a decent set of pipes.
Title: Re: HIF Manifolds
Post by: MiniDave on January 22, 2020, 09:27:46 PM
So, is the older one or newer one shorter?
Title: Re: HIF Manifolds
Post by: tmsmini on January 23, 2020, 07:14:33 AM
The older CAM 6618 manifold is the shorter one.
Title: Re: HIF Manifolds
Post by: MiniDave on January 23, 2020, 08:25:38 AM
What is the device on the throttle shaft of the carb?
Title: Re: HIF Manifolds
Post by: tmsmini on January 23, 2020, 09:07:22 AM
It is a TPS for the electronic ignition. On the woodie wagon we drove to MMW, we are using an MPi block so we are making use of a Specialist Components ECU to provide distributorless ignition.
Title: Re: HIF Manifolds
Post by: MiniDave on January 23, 2020, 09:18:34 AM
MMW in 2016? I was there.....Bruce and I took his MINI and Mini there. I didn't have my Racing Green yet, I bought it shortly after we got back IIRC.

Hard to have ignition without a distributor if you don't have an electronic system!   ;D

What do they charge for their electronic ignition setup? And once you have that, can you add their fuel injection or do you need a different ECU?
Title: Re: HIF Manifolds
Post by: tmsmini on January 23, 2020, 09:25:08 AM
Sorry MMEW last year.

It is the same ECU, but we are using the older Typhoon and now they have the Delta 400 for Minis.
Both support injection.
They had a special at Christmas time on the ignition only system and I think it was close to $800 including a trigger wheel and their sensor setup.
Title: Re: HIF Manifolds
Post by: MiniDave on January 23, 2020, 09:50:45 AM
Yikes, that's spendy...but what choice do you have? the map can be tailored?
Title: Re: HIF Manifolds
Post by: tmsmini on January 23, 2020, 10:05:41 AM
Yes, fully adjustable
If you know what you are doing
Title: Re: HIF Manifolds
Post by: 94touring on January 23, 2020, 12:56:06 PM
Can't recall if I illustrated how closely my abutment plate and throttle linkage comes to the new MS manifold but this is it.   I think if I was barely fouling I'd file down the plate or even the manifold slightly.   I can fit an index finger between the carb float and bulkhead too fyi.
Title: Re: HIF Manifolds
Post by: tmsmini on January 23, 2020, 12:59:38 PM
And this is the MS manifold with the big MiniSpares on the top? Your bracket on the plate definitely looks smaller than mine.
Title: Re: HIF Manifolds
Post by: 94touring on January 23, 2020, 01:07:59 PM
I made my own 6mm spacer out of some scrap aluminum plates I had laying around.  Maybe this will help give some measurements to compare to what you're using. 

Probably helps if you could see the scale...top is inches 1/16" increments and bottom is MM. Flange that meets the carb face is roughly 1/4" on the top.
Title: Re: HIF Manifolds
Post by: MiniDave on January 23, 2020, 01:47:55 PM
If you're missing the plug for that manifold (where the orange RTV is), I have a spare.....
Title: Re: HIF Manifolds
Post by: tmsmini on January 23, 2020, 03:09:47 PM
My plan is to track down a good used CAM6618 for the injected car. It does not use a spacer so there is no other place to get any relief. I already use a longer dogbone and it is still tight.
For the HIF car, I will try a smaller spacer and adjust the bracket and throttle quadrant as necessary when I rebuild the carb next.
Title: Re: HIF Manifolds
Post by: tmsmini on February 07, 2020, 12:39:05 PM
I was looking for a decent used CAM 6618 and ran across what is a "new" one on ebay in Germany. I will find out what means next week.
In the meantime I was looking at the very used one I have and ran across some old fittings for a Holley I never used. Turns out they were 9/16, very close to the ID of the pipes and I had the tap. I tried to tap the "pipes," but the rust prevented a clean thread. One side grabs pretty good, but you know if you turn it anymore and it will strip. The other only catches a thread or two and still wobbles.

Loktite makes some pretty amazing thread sealers/lockers these days, I was wondering if anything could be used. It only needs to hold 13 psi.
Title: Re: HIF Manifolds
Post by: MiniDave on February 07, 2020, 01:32:26 PM
A good case for JB Weld? I've fixed some stuff around the house with that and our water pressure is about 50psi.

Clean all the oil out, wipe a little JB around the threads in the manifold and a little more around the treads of the fitting, then screw them in and let set up. Should work fine.

Alternate #1, do you know anyone with a Tig who could weld up the holes, then you can re-drill and tap fresh threads for the fittings you have?

Alternative #2, drill them out and put a small freeze plug in and don't use them for water?

Alternative #3, have someone with a lathe (WillieB?)  make you an insert with a step in it, one end sized for the hose and the other for the clean bore, then bore them oversize and press in the new inserts? Looks stock when it's all done.
Title: Re: HIF Manifolds
Post by: tmsmini on February 07, 2020, 05:15:15 PM
Did not think of JBWeld, certainly a possibility. I wish the fittings were deeper. I threaded the pipe on each side as far as it would go, I am guessing about 1.5 inches. The fittings are only .5 inch.
There is a guy on the MiniForum who has redone the pipes on the SPi and is now looking into making them for the turbo.
This is for the injected car and it seems to be happier with the pipes connected.

Steve mentioned the process to replace previously, but I don't think I have the patience.

The "new" manifold is in New Jersey today, so it is on its way.
Title: Re: HIF Manifolds
Post by: tmsmini on February 08, 2020, 03:19:52 PM
Never knew what a turbo inlet manifold looked like
Title: Re: HIF Manifolds
Post by: MiniDave on February 08, 2020, 04:04:42 PM
Was this supposed to be the new one?

The corrosion on those pipes says otherwise....
Title: Re: HIF Manifolds
Post by: tmsmini on February 08, 2020, 04:27:52 PM
No, that one is not the one I am waiting for. Same person has some used HIF items.
I had just never seen a turbo manifold before. Turbos also use an HIF 44, but a sealed version.
Title: Re: HIF Manifolds
Post by: tmsmini on February 12, 2020, 02:17:36 PM
New manifold came today and it does look new. It should give me a little clearance to get the air filter on.
It does need some clean up and I may have to have a machine shop touch up the mounting ears for the later style manifold nuts to work.