Taylor bright Posted March 12, 2018 Share Posted March 12, 2018 Well this is the first post in what hopefully may become either another failed project or helpful how to, what am I going to try do? Put a Honda cylinder head on a small crank block, which cylinder head you may ask, a D series head one of the 4 valve per cylinder potentially vtec heads, why? Because the cylinders almost line up. What's happened so far, I bought a small crank engine (props to spitfire graveyard for a £100 engine) I've taken the head off cleaned it up and am debating getting it flowed and unleaded for the engine in my spit (if anyone knows someone good near Essex message me) Quote Link to comment Share on other sites More sharing options...
JohnD Posted March 12, 2018 Share Posted March 12, 2018 Wow! Ambitious! Four valves per cylinder, crossflow, pent-roof pistons, two Ohd. camshafts! But boring old caution makes me ask, how will you drive the camshafts? John Quote Link to comment Share on other sites More sharing options...
JohnD Posted March 12, 2018 Share Posted March 12, 2018 Sorry, nothing happened for so long, I pressed "post" again. And again. How do you delete duplicates? J Quote Link to comment Share on other sites More sharing options...
Taylor bright Posted March 12, 2018 Author Share Posted March 12, 2018 Well the pistons are actually relatively straight forward the ones I will use are on ebay labelled vitara turbo d16 pistons, but to fit them I need to get a 75mm bore which I think I'm going to have to sleep the block so I can move cylinders 2 and three closer a touch, the cross flow isn't a bad thing hopefully the exhaust is the right side and I just bring the intake onto the passenger side if not the passenger can have the "hot seat", cams are a belt driven thing on the d16 also a d16 spins the "wrong" way so I will have to see if they are able to run in reverse or if I'll have to pass the belt past them in the correct way for the cam, also not all the d16 variations were dohc some are single overhead cam On another note I have no idea how to delete duplicates but if you work out how let me know Quote Link to comment Share on other sites More sharing options...
Clive Posted March 13, 2018 Share Posted March 13, 2018 Quoted from JohnD- Sorry, nothing happened for so long, I pressed "post" again. And again. How do you delete duplicates? J Not sure, but it seems the moderator option works! Quote Link to comment Share on other sites More sharing options...
JohnD Posted March 13, 2018 Share Posted March 13, 2018 Taylor, Don't know Hondas, but cam belts usually run in the open air (well, behind a safety cover), while the Triumph chain is enclosed. I'll be fascinated to know how you will block the open access at the from of the engine, without a timing cover, lubricate the camshafts, and deal with all the other differences. I'm not trying to diminish your enthusiasm, quite the reverse! If you can do it, I'm all admiration, and posibly copying! John Quote Link to comment Share on other sites More sharing options...
Taylor bright Posted March 14, 2018 Author Share Posted March 14, 2018 Why do you have to uncover the timing chain I was going to leave that because the original cam in there because it runs the oil pump and dizzy I was just going to take the pushrods out so that I can leave the cam in and maybe change the crank pulley so I can run a proper belt, seeing as I don't have a fan belt because it's an electric fan Quote Link to comment Share on other sites More sharing options...
thescrapman Posted March 14, 2018 Share Posted March 14, 2018 i am sure some did a kit for converting to a cam belt manyyearsago. or perhaps it was just someone's project Quote Link to comment Share on other sites More sharing options...
JohnD Posted March 14, 2018 Share Posted March 14, 2018 I'm sorry, Taylor, I said I didn't know Hondas, and I saw the four valves per cylinder and assumed, two cam shafts! All D-series had a single OHC! Doh! So, why not! Go for it, but please tell us how! John Quote Link to comment Share on other sites More sharing options...
Taylor bright Posted March 14, 2018 Author Share Posted March 14, 2018 Hi John I'm afraid it's not that simple not all d16 engines are single overhead cam some are dual cams, just have to choose wisely on which I want Quote Link to comment Share on other sites More sharing options...
Clive Posted March 14, 2018 Share Posted March 14, 2018 Quoted from thescrapman- i am sure some did a kit for converting to a cam belt manyyearsago. or perhaps it was just someone's project I remember that! Well, the fact it happened. In the TSSC mag. The timing chain cover was replaced with a thick ali plate, with grooves machined for oilways. It used std sprockets, must have been machined to suit the crank and cam. I don't remember a tensioner, but that can't be too hard? Struggling to envisage how to reverse the direction though. Quote Link to comment Share on other sites More sharing options...
Taylor bright Posted March 15, 2018 Author Share Posted March 15, 2018 Run the cams the direction of the engine, and if they aren't symmetrical to be run the wrong way get a reverse cam ground Quote Link to comment Share on other sites More sharing options...
drofgum Posted March 15, 2018 Share Posted March 15, 2018 Quoted from cliftyhanger- Quoted from thescrapman- i am sure some did a kit for converting to a cam belt manyyearsago. or perhaps it was just someone's project I remember that! Well, the fact it happened. In the TSSC mag. The timing chain cover was replaced with a thick ali plate, with grooves machined for oilways. It used std sprockets, must have been machined to suit the crank and cam. I don't remember a tensioner, but that can't be too hard? Struggling to envisage how to reverse the direction though. Cliftyhanger, Probably the simplest way to reverse the rotation is to interpose a single pair of gears in the cam drive. Cheers, Paul Quote Link to comment Share on other sites More sharing options...
Clive Posted March 15, 2018 Share Posted March 15, 2018 I thought about gears as a solution, but it is suddenly getting complex. Not to mention expensive!! The idea of a reversed cam grind makes a lot of sense. Quote Link to comment Share on other sites More sharing options...
Taylor bright Posted March 16, 2018 Author Share Posted March 16, 2018 I suppose the real question is do I try get a vtec head or just a non vtec head Quote Link to comment Share on other sites More sharing options...
Clive Posted March 16, 2018 Share Posted March 16, 2018 Have a serious think about it. The Vtec is a straight on/off? if so can be controlled by any ecu, or even shift light. If a VVT then you need a clever box of tricks..... However, a thought should be given to when Vtec kicks in. And the rev limitations of the Triumph short engine. A fixed cam may well be a better bet. And simpler to get working. Quote Link to comment Share on other sites More sharing options...
Taylor bright Posted March 16, 2018 Author Share Posted March 16, 2018 Vtec on older engines is a oil pressure related thing, as revs increase oil pressure increases causing some stuff to move engaging vtec Quote Link to comment Share on other sites More sharing options...
nang Posted March 17, 2018 Share Posted March 17, 2018 An I missing something here? Surely easier to fit a vtec engine complete than trying to adapt an old Triumph lump. I don't see what you would achieve without a lot of shagging around. Just my thoughts for what they are worth. Not wanting to decry what you're attempting. Tony. Quote Link to comment Share on other sites More sharing options...
JohnD Posted March 17, 2018 Share Posted March 17, 2018 Taylor, Perhaps not remarkably, great minds and all that, but you're not the first to think of a Honda D cylinder head. See this thread over on the Triumph Experience, and the contribution by Carter Shore, who is a Triumphero whose opinion I very much respect: https://www.triumphexp.com/phorum/read.php?22,1499296 No outcome, but perhaps you should collaborate with the OP on that thread, John Kontos in Chicago. John Quote Link to comment Share on other sites More sharing options...
Taylor bright Posted March 17, 2018 Author Share Posted March 17, 2018 I did infact message him and very little came from it Quote Link to comment Share on other sites More sharing options...
Taylor bright Posted March 17, 2018 Author Share Posted March 17, 2018 I did infact message him and very little came from it here is the contents of the reply I received from him "As I explained, the bore spacing is probably the biggest challenge. Second is altering the Spitfire block to accommodate the D16 head studs/bolts. The holes not only have to match the pattern, they also must be strong enough to carry the clamping loads without excessive distortion. Then there is the issue of cooling passages, which must match up between head and block. And finally the cam drive. Since the D16 rotates in the opposite direction to Spitfire, either a different custom ground cam is required, or a rotation reversing drive must be employed. This could be done by using a longer chain, with a pair of idler pulleys that route the chain around the bottom half of the sprocket rather than the top, which gives reverse rotation. Or a reversing gearset could be employed that operates from the front of the Spitfire cam or crankshaft sprocket. The Spitfire oil pump and dizzy is driven from the center of the camshaft, and so a 'dummy' cam is still required. Hope this helps." However in the post where he mentioned many other things it did make me think about the d13c cylinder head which has a 73.7mm bore which is suspiciously close to the spitfire bore Quote Link to comment Share on other sites More sharing options...
mikeyb Posted March 17, 2018 Share Posted March 17, 2018 Quoted from thescrapman- i am sure some did a kit for converting to a cam belt manyyearsago. or perhaps it was just someone's project A chap in Mayland (or was it Woodham ?) did it. I seem to recall one of the specilaists subsequently offered a kit - Jigsaw maybe? Quote Link to comment Share on other sites More sharing options...
Nick Jones Posted March 18, 2018 Share Posted March 18, 2018 Interesting idea and I love crazy mods as much as anyone...... However, I can't help thinking that you are trying to do something really very difficult for no very good reason. Basic point to consider is that even with the original valve gear and head the 1300 small crank bottom end can be tuned to the limit of it's strength so alrge amounts of tricky and expensive engineering work is not likely to gain you much in the way of grunt. I would say drop the whole D-series in and have done with it, but then you come back to the reason why they are rarely used outside of Hondas - wrong direction of rotation. Also bear in mind that even the original block with a OHC head on it might be too tall to fit under the Spitfire bonnet? I know there is the fairly successful A-series 16v twin cam conversion using the BMW K series bike head, but that is alot easier in technical terms as the bores and even most of the head studs line up and both engines are designed to rotate in the same direction. It was also driven by the regs in some competition series requiring the OE pattern block to be used but allowing free choice of head. If you are determined to keep with a OE (ish) Triumph block then perhaps a small turbo or supercharger? Mr Bowlers supercharged Mk3 was a bit of a monster! Nick Quote Link to comment Share on other sites More sharing options...
Taylor bright Posted March 18, 2018 Author Share Posted March 18, 2018 Well the idea behind the Honda lump is that the bores are so close to lining up and some of the coolant passages line up as well, so why not see if it's reasonably do able and if it is then I can start toying with it to see what I can get out of the bottom end and at what point I have to look at the bottom end. Remember a d16 head also gives immediate use to cheap turbo kits (around £500)as well as a fuel injection manifold designed for it so it could make life easier when coming to fuel inject it as no manifold has to be made Quote Link to comment Share on other sites More sharing options...
Taylor bright Posted March 22, 2018 Author Share Posted March 22, 2018 It might also make sense from a driveability and fuel economy sense, that head flows so much better and with the cams it has it might be even more fuel efficient yet have a bit more power, not to mention it should be more drivable than a highly tuned engine that idles higher and the such Quote Link to comment Share on other sites More sharing options...
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