dressing-up a 2.5 (17H) petrol to look like a 2.25?

[twodoorgaz]

Hello folks.

 

After a long search I've tracked down a 17H 2.5 petrol for SIIA build. Here are some pictures for… well, no reason at all - but we all like pics don't we? (scroll down for the actual question)

 

Now my love for this engine comes from the timing cover. As it retains a timing chain (unlike TDis, 2.5 NADs, etc), it makes a perfect fit in the series engine bay and the engine note seems 'right' just with a smudge more grunt.

It will be getting a full rebuild before fitting, and I'm obviously missing a few bits. I realise I can drop it straight in with a tweaked exhaust, appropriate carbs and a modd'd cable throttle but as I'm reconing it anyway, I'd like to rebuild it a little more subtle.

 

I remember there was a chap on the forum who dressed a 2.5NAD to look like a 2.25d and was wondering if anyone could advise on the bits I can change over for a 2.25?

Ideally I'd like to do the following. Can anyone advise if this will work without of course impeding the performance of the engine?

1. 2.25 Timing cover inc. water pump & 4-bladed fan, pulleys and starting handle crank dog.
2. 17H Sump
3. 2.25 Alternator mounts.
4. 2.25 Engine mounts
5. 2.25 Oil filler tube to side of block
6. 2.25 Lift pump (this one already has one, though I did think it should have been electric)
7. 2.25 Cylinder head and thermostat neck (*NB the head will be going to ACR for stage 2.1, so don't think it matters whether the donor is 2.25 or 2.5 - hardened valve seats if coming from a 2.5)
8. 17H Inlet/exhaust manifolds and correct Webber carb (have found a set already) - BUT I'm also saving to see if I can run to the ACR SU kit plus manifolds which can fit both the 2.25 and 2.5 - this would be ideal as it looks lovely and period. Realise the 2.25 zenith will fit, but suspect it will strangle the engine.
9. Stage 1 V8 cable throttle and 17H cable (easy to knock something up but I have both already)
10. 17H Flywheel and housing (its being bolted to a stumpy R380 so I have so no need to worry about this)
11. 17H Starter motor (plus slight alteraton to wiring) - seems smaller and more powerful than the standard Series fare.
12. 17H Spin-on oil filter
13. 2.25 rocker cover
14. 2.25 heater hoses and connectors
15. Standard Lucas dizzy (or MJ if I get giddy)
16. Painting the block duck egg blue (wrong for a 5MB, but right for a IIA)
17. Custom exhaust - either Steve Parker's off the shelf one or ACR's off the shelf one to match the manifold.
18. Finally - for the 2.25 donor bits, does it matter if these are the common imperial ones (thinking the head here mainly) or the rarer late metric items? I'm guessing if I use the correct fasteners then it doesn't matter but would welcome confirmation.

Thank you very much.

 

 

 

 

Edited June 22, 2017 by twodoorgaz

[Quagmire]

I do love a 2.25 petrol, and can only imagine that the 2.5 must be the same but better (although i have never come across one in the flesh). 

I will be watching this with interest - keep posting the updates as they happen 

*edit - are you dressing it to look like a series 2.25 or the 2.25 (aka 2.3) in the early coilers? My 90 had the 2.25 fitted when I first bought it, was a great engine just a bit slow to pick up speed when merging onto a motorway. 

[twodoorgaz]

Hi - I'd be glad to post up pictures here.

 

Dressing it up to look like either a 3MB 2.25 from a SIIA or I'd even settle for it looking like 5MB 2.25 from a late SIII. The carb will be the big giveaway - if I spring for the SU kit it will look like a tweaked Series engine.

Not going to the far end of a fart with it - just a few swaps while I have it in bits to make it look and fit that little bit less obvious.

 

[David Sparkes]

I see you are intending to retain the 17H spin on oil filter.

If you wish to 'give the impression' of a basic 2.25, perhaps with 'apparently period' modifications, then installation of the 2.25 style oil filter is a strong indicator of the 2.25 engine.

I realise that 'now', and for some considerable time, owners have fallen over themselves to upgrade to the spin on oil filter, but did they do that in the '60's and 70's, the time period you are hoping to emulate?
Sure, getting a clean (not messy) oil change with a 2.25 filter takes a little more effort and expertise, but I think it's doable, and practise will make it easy.

Regards.

[Snagger]

I would plumb for the late "2.3" SIII engine exterior, as that was also 5mb and both blocks have the external reinforcing webs above the sump line that are missing fro the 3mb engines.  I would be curious to know if you could just swap the crank shaft, cam shaft, rods and pistons from the 2,5 in to a 2.25 5mb block - the 2.5NAD, TD and 200Tdi all shared the same crank and cam shaft, amongst other things, so it's possible that this would apply to the petrol models, given that the volume increase was due to the increased sweep from the new crank.

 

Anyway, given that the later oil filter housing can be installed on the old engines, I see no reason the reverse would be a problem.  I suspect the old manifolds would bolt up, needing the stud holes drilling a little wider at worst, though they may strangle the 2.5 a little.  The alternator mounting is the same and engine mounts would be a direct swap with no alteration.  The flywheel housings should be interchangeable if you want to swap them, but I don't know about the flywheel itself, and that may decide whether the older style starter with separate solenoid can be used.  I'd be surprised if the timing cases can't be swapped, allowing you to use the four bladed fan, but I used that fan on a 12J by enlarging the bolt holes in the fan hubjust enough to fit the slightly different pattern of the 12J pump's flange.

[Quagmire]

On 6/25/2017 at 1:22 PM, Snagger said:

  I suspect the old manifolds would bolt up, needing the stud holes drilling a little wider at worst, though they may strangle the 2.5 a little.  

We did the opposite to what is proposed in this thread and fitted the later manifold and carb setup from a "2.3" to the 2.25 in a series. All bolted straight on. The exhaust had to be tickled with the grinder and glued back together with the welder though as it fouled the gearbox mount. 

[Gazzar]

I can confirm that the series paper filter type oil filter housing fits a later block, using metric bolts, I had one on my di200.  

G.

[Daan]

On 22/06/2017 at 9:40 PM, twodoorgaz said:

Hello folks.

 

 Can anyone advise if this will work without of course impeding the performance of the engine?

1. 2.25 Timing cover inc. water pump & 4-bladed fan, pulleys and starting handle crank dog.   yes, except the crank dog, you can cut this off and weld it to the new crank bolt. Also, if there is a timing belt now, you need to pull a core plug out of the oil gallery.
   1. 17H Sump         yes
2. 2.25 Alternator mounts.     yes
3. 2.25 Engine mounts          yes
4. 2.25 Oil filler tube to side of block          yes
5. 2.25 Lift pump (this one already has one, though I did think it should have been electric)    yes
6. 2.25 Cylinder head and thermostat neck (*NB the head will be going to ACR for stage 2.1, so don't think it matters whether the donor is 2.25 or 2.5 - hardened valve seats if coming from a 2.5)     yes
7. 17H Inlet/exhaust manifolds and correct Webber carb (have found a set already) - BUT I'm also saving to see if I can run to the ACR SU kit plus manifolds which can fit both the 2.25 and 2.5 - this would be ideal as it looks lovely and period. Realise the 2.25 zenith will fit, but suspect it will strangle the engine.    yes
8. Stage 1 V8 cable throttle and 17H cable (easy to knock something up but I have both already)   not sure
9. 17H Flywheel and housing (its being bolted to a stumpy R380 so I have so no need to worry about this)   yes
10. 17H Starter motor (plus slight alteraton to wiring) - seems smaller and more powerful than the standard Series fare.    no, it is a 3 bolt starter motor
11. 17H Spin-on oil filter   yes
12. 2.25 rocker cover   yes
13. 2.25 heater hoses and connectors   yes
14. Standard Lucas dizzy (or MJ if I get giddy)    yes
15. Painting the block duck egg blue (wrong for a 5MB, but right for a IIA)   yes
16. Custom exhaust - either Steve Parker's off the shelf one or ACR's off the shelf one to match the manifold.   yes
17. Finally - for the 2.25 donor bits, does it matter if these are the common imperial ones (thinking the head here mainly) or the rarer late metric items? I'm guessing if I use the correct fasteners then it doesn't matter but would welcome confirmation.      Just mix them...

Daan

 

 

 

 

 

[twodoorgaz]

Thank you very much! Just what I was looking for.

[Daan]

Reading it back, the 3 bearing and 5 bearing bell housing are different in the oil seal area, plus the starter motor issue. The 380 has a different stud pattern as well I think, so you probably need a 300 tdi bell house on the engine.

 

Daan

[twodoorgaz]

Hi folks.

 

thought I'd update this thread. I have nearly everything I need now (I think). Its getting bolted to a Stumpy R380 (already got) - the stumpy R380 has the same bell housing pattern as the earlier, short bell housing, LT77 so it should be a factory fit to the 17H flywheel housing I have.

 

So I have a 17H block with flywheel, flywheel housing and oil filter housing. Its already got a series-style fuel pump:

 

And then I've bought:

 

from a '901' Series III petrol engine...

• Sump
• 8:1 head (will be recon'd to 9:1, U/L and 17H spec valves)
• Rocker cover
• Side fill oil tube and baffle
• Rocker cover
• Dipstick (I can straighten and re-use the metric dipstick tube from the 17H)
• Timing cover
• Water pump
• Fan and pulley
• Thermostat housing
• Engine mounts
• Rocker assembly, timing assembly and a big heap of fasteners (I'll probably replace these with new but handy to have for mock-up - especially the fasteners as I'll be mixing metric and imperial by part number)

 

and...

 

 

an inlet and exhaust manifold from a 2.5 petrol.

 

And… I have a stage 1 v8 cable throttle assembly (sorry, no pics - its in the loft)

 

Still to track down are:

1. Series IIA heater inlet and outlet unons/taps (should screw into the imperial head)
2. A Series III alternator bracket
3. A Weber 2.5 17H weber carb (32/34 DMTL) and inlet plenum
4. Crank pulley and starting handle dog from a 5MB 2.25 (late SIII or early one-ten)

 

Not a million miles away from starting the tear-down, machining and rebuild. Any tips on the recipe for this franken-engine would be very welcome indeed.

Edited August 3, 2017 by twodoorgaz

[Daan]

That should go together ok. I would suggest splitting the inlet and exhaust manifold; warming up the inlet manifold is only helping when it is -10 or so, otherwise you loose efficiency. I used the 2.25 exhaust manifold, cut it it down in this area and welded a plate on top of it.

 

Daan