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moditup
United Kingdom
83 Posts |
 Posted - 04 Jan 2012 : 21:00:41
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| Hi all, is there any chance a Hillman Hunter 1500 engine would run with a Holbay head fitted, picked a full engine up Monday but its got the AM3 Holbay head,Holbay rocker cover,but steel sump only bought for the conrods and block so slightly confused, its got stomberg carbs fitted and no vacuum on dizzy ? |
Edited by - moditup on 04 Jan 2012 21:10:02 |
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bigt80
United Kingdom
1052 Posts |
Posted - 06 Jan 2012 : 19:17:06
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Mmmm, sounds like a bit of a hotch-potch. Steel sumps were used on Holbays, ally only fitted to all early models originally. AM3 not 100% fool-proof on indicating Holbay head. I have seen it on std's although most AM2 with occasional AM4 (late ones). Rocker covers interchangeable, so no proof it's a Holbay head from that. What manifold has it got on it? If running strombergs on std manifold then I'd say likely it was std head. What about exhaust manifold? Std too? I'd say you might just have a std head? More thoughts from others I'm sure  |
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1922
United Kingdom
549 Posts |
Posted - 07 Jan 2012 : 11:42:41
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Don't think there is any such thing as a 1500 engine with an alloy head - are you sure it's not really a 1725?
The alloy heads have the valves in a different order to iron heads - so the cam would have to be a 1725 one.
Maybe you have a 1725 that had been fitted to a 1500 Hunter?
Measure the rod length and compare to your other engine.
Oh - a post a picture of the underside of the head, and the top please.
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moditup
United Kingdom
83 Posts |
Posted - 07 Jan 2012 : 12:36:10
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I will whip the head off tommorow and post a few pictures of the full engine, the other head I have has got Holbay cast into the head behind the thermostat housing, this one hasn't.
Oh by the way its got a 4 branch exhaust manifold fitted but its been cut through where it joins the exhaust, another thing that came with it in a bag of bits was a round AC air filter with twin intake pipes but these I suppose are run of the norm ?
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Edited by - moditup on 07 Jan 2012 14:16:53 |
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moditup
United Kingdom
83 Posts |
Posted - 08 Jan 2012 : 10:28:28
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Have a look at this, the head looks like a holbay but the piston
are a few mmetre short of TDC unlike my other block. IMG00086-20120107-1224.jpg |
Edited by - moditup on 08 Jan 2012 10:38:53 |
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arrocuda
United Kingdom
501 Posts |
Posted - 08 Jan 2012 : 13:33:50
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A friend of mine on the RR forum is also considering putting an alloy head on a 1500 block. Personally..... I don't get it. I can see one or two good reasons for swapping the complete lump but very few for swapping the head out. Assuming the objective is to get more power.... (I could be wrong, but feel free to correct me) the increase in cubic capacity alone could be considered as 225 good reasons to go down the 1725 route before you even look at adding Holbay tuning devices.
Be interested to know why you were planning to exchange the heads in the first place.
Tim.
Building the 'Mark II' fastback Rapier ('Arrocuda'). |
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moditup
United Kingdom
83 Posts |
Posted - 08 Jan 2012 : 14:30:29
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| Hi, no I bought what I thought was a hunter 1500 engine for the block and con rods to build a big capacity engine and to scrap the head,crank,pistons ect, only when I went to pick it up I discovered it had an alloy head with the AM3 stamp which possibly indicates an holbay head, the car it came from was in the farmers field in a pile of bits (rotten) but the boot lid said 1500, but its deffo an Holbay head so maybe it was a Hunter GLS ? |
Edited by - moditup on 08 Jan 2012 14:34:03 |
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JPSH120
United Kingdom
1183 Posts |
Posted - 08 Jan 2012 : 15:01:07
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If the head is in good nic and surplus to requirements I would be interested. Cheers.
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arrocuda
United Kingdom
501 Posts |
Posted - 08 Jan 2012 : 16:16:36
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You might just have gotten lucky there!  Is unlikely that someone swapped the bootlid and forgot, or never got round to, changing the badge as it would be sporting twin weber 40's and have had all the extra luxuries the GLS had over the 1500 DeLuxe..... more likely that someone at some time decided that 1500cc's just wasn't enough and bought a second hand 1725 engine and attempted to tune it a little.
Either way..... nice find!! 
Building the 'Mark II' fastback Rapier ('Arrocuda'). |
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1922
United Kingdom
549 Posts |
Posted - 08 Jan 2012 : 16:58:52
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Holbay heads have different shape combustion chambers (heart shaped instead of bath tub shape), sometimes there is a serial number starting "P" on the front left on top.
If it was a Hunter GLS you should have twin weber 40 DCOE carbs (as Arrocuda said), "Holbay" on the alloy rocker cover/
Early cars have an round AC air cleaner with two inlets (it looks like a saucepan with two handles), later cars have a oblong air filter.
The pistons will be flat top (like a 1500).
The GLS/H120 cam is higher lift (320 thou), the standard cam 295 or 298. If you have a vernier gauge or micrometer you can measure the lift. Maybe you got lucky and found another Holbay engine!
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moditup
United Kingdom
83 Posts |
Posted - 08 Jan 2012 : 17:28:45
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Hi, yes its got the holbay alloy rocker cover and the heart shaped chambers on the head same has my other one,
also in a box of bits that come with it I do have the AC air filter with twin pipes, tried to post a few pictures of the engine/head but they won't download !
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arrocuda
United Kingdom
501 Posts |
Posted - 08 Jan 2012 : 17:52:59
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The key to the camshaft maybe the short block. If the head has the recessed combustion chambers you must have removed it. If the pistons in the block are flat top rather than dished then chances are you have the high lift camshaft too. Also..... the Holbay engine usually has tubular push rods that are considerably lighter than the solid types. I say usually cos I think someone on here said that is not always the case cos some of the later ones had solid push rods but I might have imagined that bit.
Building the 'Mark II' fastback Rapier ('Arrocuda'). |
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moditup
United Kingdom
83 Posts |
Posted - 08 Jan 2012 : 18:20:59
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The push rods that I have taken out are cast steel and quite heavy so asasume are solid, yes its has flat top pistons but so did the 1500 hunter, my other standard 1725 engine has dished pistons, what is the holbay cam number if its stamped with onea, the other Holbay engine I have is seized solid so haven't yet taken the cam out, still soaking bores with coka cola
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Edited by - moditup on 08 Jan 2012 18:24:44 |
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arrocuda
United Kingdom
501 Posts |
Posted - 08 Jan 2012 : 18:38:35
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Just looking at a spare camshaft I have here and if you hold it so as the driven end is to your left..... free end to your right, you will see 2 numbers. Mine is MC24794 to the right of the 2nd lobe along and to the right of the 5th lobe along it has 71981553. More importantly... below this number it has 'Holbay 5128' etched rather than cast as are the other markings on it.
Building the 'Mark II' fastback Rapier ('Arrocuda'). |
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moditup
United Kingdom
83 Posts |
Posted - 08 Jan 2012 : 18:54:19
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Will strip the cam out and check numbers, I don't think this engine is correct I think its possibly a botch job like previously mentioned.
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1922
United Kingdom
549 Posts |
Posted - 08 Jan 2012 : 20:02:57
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My H120/GLS cam has the same MC24794 and 71981553 numbers cast on it - but this one is new to me, do you know what numbers are on the 295 cam (mine is a bit tricky to get to at the moment!).
Arrocuda - could that "5128" be "E128"?
The E128 was the cam used in Holbay Rally and Marathon engine - a nice thing to have. It has a lift of 330 thou, ten more than the normal H120/GLS cam.
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Topic |
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Hunter 1500 engine
