Tobias Posted October 22, 2009 Share Posted October 22, 2009 I Have a 3,5 carbed engine, normal dizzy and vee belt front end. I hay be able to get a cheap 4.6, unknown condition and at the moment unknown what parts might be there and missing. My intention is to build a new engine with MS'n EDIS with the best combo in the cheapest possible way. I have a TF727 that I intend to keep using. Will the flexplate/adapter fit the 4.6 crank? Starters fit across? Can I build up a vee belt front end on the 4.6 block? Will the 4.6 heads fit my 3.5 block manifolds? Other pit falls? Tobias Quote Link to comment Share on other sites More sharing options...
Bull Bar Cowboy Posted October 22, 2009 Share Posted October 22, 2009 I Have a 3,5 carbed engine, normal dizzy and vee belt front end. I hay be able to get a cheap 4.6, unknown condition and at the moment unknown what parts might be there and missing. My intention is to build a new engine with MS'n EDIS with the best combo in the cheapest possible way. I have a TF727 that I intend to keep using. Will the flexplate/adapter fit the 4.6 crank? Starters fit across? Can I build up a vee belt front end on the 4.6 block? Will the 4.6 heads fit my 3.5 block manifolds? Other pit falls? Tobias Will the flexplate/adapter fit the 4.6 crank? Yes Starters fit across? Yes ......... there are two sizes but both fit Can I build up a vee belt front end on the 4.6 block? yes, but you may /will need a spacer for the crank pulley Will the 4.6 heads fit my 3.5 block ? yes, but you will need to use composite head gaskets. manifolds? yes...........there are many combinations, however, some are better then others. I would guess the 4.6 is a GEMS and that will be OK. Quote Link to comment Share on other sites More sharing options...
Tobias Posted October 22, 2009 Author Share Posted October 22, 2009 Thank you, Cowboy. So no real hurdles, just better and less godd mixes. I will get back as soon as I've taken a look at the mess. I have a flapper intake complete with injectors, regulator, TPS and so on which I had intended to put on the carbie for the MS conversion, but if the 4.6 intake is better I will of course use that. We'll see. T Quote Link to comment Share on other sites More sharing options...
Quagmire Posted October 22, 2009 Share Posted October 22, 2009 Heads and manifolds are straight swap. Timing cover swap is more complicated as the 4.6 has the crank driven pump (better) so the crank nose is longer? Also the 3.5 has a hole for a dizzy and dizzy driven oil pump. I imagine starters will swap over with no problem. As with all my posts- someone will need to confirm. Quote Link to comment Share on other sites More sharing options...
Quagmire Posted October 22, 2009 Share Posted October 22, 2009 wow! too slow on the posting there Quote Link to comment Share on other sites More sharing options...
Tobias Posted October 29, 2009 Author Share Posted October 29, 2009 Now the engine is in the workshop. Just had to pop the lids and verify that it's really a 4.6, and YES! it is! Engine number: 60D14595A No sign of washing in either piston crown or head combustion surface. When i feel on the top deck of the block at liner block interface i feel the liner sitting proud of the block, just creating a tiny ridge possible to feel by the fingernail. The number two bore on the right however has no such ridge. Is it a slipped liner? There were no headgaskets in place so no autopsy were possible on those. The history of the engine is completely unknown. It has it's origins within the warranty loop, so in some stage it has been exchanged for a good engine by the factory. What would cause that? What should I look for, apart from "slipped liner"? Tobias Quote Link to comment Share on other sites More sharing options...
Tobias Posted November 1, 2009 Author Share Posted November 1, 2009 Iiv'e started tearing down and looking at pieces more: The water pump has some scratches, is this worrisome? There is talk about a spacer for the crank pulleys when using a 4.6 front end. When I measure crank nose to oil pump gear I have 48mm free length: while the crank pulley itself is only 42mm front outer edge to the ledge where it will hit the seal. Is this why I need the spacer, is the spare to sit on the crank nose before the pulley? When I measure straightness of the heads they are curved 0,25 resp 0,30mm lengthwise and both about 0,10mm crosswise in the worst spot. This seems excessive and should I have them faced? I will put it on the engine stand and have a look in the sump and lift a main bearing or two, but if that looks as fine as the upper end, I'm tempted to just slap it together, with perhaps a refacing of the heads and new gaskets and leave it at that. Tobias Quote Link to comment Share on other sites More sharing options...
Aragorn Posted November 1, 2009 Share Posted November 1, 2009 Heads sound bananna'd, so ye they need skimmed. Block face might need skimmed too. The fact that the heads are bent probably indicates its been overheated, so i'd be wanting to check the liners very closely. I would keep the 4.6 front end too, as you really want the newer oil pump. Quote Link to comment Share on other sites More sharing options...
Tobias Posted November 1, 2009 Author Share Posted November 1, 2009 Thanks, Aragorn. I tried to check the block faces and could only measure less tha 0,05 mm. So if there are normally no tendencies for local sinking, as in 4-valve head designs, I should be fine. Any ideas on how to check liners? The heads are marked 45 00 so I assume week 45 of 2000 which means the engine is a very late one. Soe people seem to think the liner issue is not as bad on the latest ones... I hope it's just head skimming and gaskets About the front end. I really want the pulleys to be vee-pulleys, since Ive all vee belt ancillaries and built up brackets for all the ancillaries I want. I'd really not fancy nouting new ancillaries/pulleys to get it all working on seprentine. Esp. the york AC pump for OBA. Does the water pump for serpentine front end rotate in the same direction as for a vee belt system. I.e. can I run the serpentine water pump in the same rotation as the engine and just make up a vee belt pulley for it. Should I drop my anxiety and run a serpentine front end? T Quote Link to comment Share on other sites More sharing options...
Aragorn Posted November 1, 2009 Share Posted November 1, 2009 The way i see it, the oil pump is more important than an anciliary drive, especially on an engine thats know for oil pump issues. I've no idea if you can use the serp waterpump with Vee pulleys, perhaps if you look at the belt routing you can work it out. Not sure on checking the liners, but didnt you say one measured lower than the rest? Quote Link to comment Share on other sites More sharing options...
Tobias Posted November 1, 2009 Author Share Posted November 1, 2009 Aragorn: I'm not sure it measures lower. It's just that when I feel over the border between top deck and liner I can feel the edge between deck and liner on most liners, but not No2 on right. But today I felt it, so it is a bit different around the circumference of the liners, so not a good measurement at all, in fact! Will look for pressure testing facilities here. If I have to go serpentine I think I'll ditch the later timing cover and go for the earlier. What is it that is so golden about the later oil pump? Is it mainly the drive by distributor or is it something else as well? Tobias Quote Link to comment Share on other sites More sharing options...
Aragorn Posted November 1, 2009 Share Posted November 1, 2009 Surely ditching the later timing cover also ditches the later oil pump? The later pump is just better all round. The earlier engines suffer from oiling issues due to the crappy pre-94 pump. Quote Link to comment Share on other sites More sharing options...
Tobias Posted November 1, 2009 Author Share Posted November 1, 2009 Aragorn: i hear you on the later oil pump, but I can not see how I can with reasonalble effort/expense duplicate the ancillary system I have now on the vee belt system. I have/need: Crrank, water pump, York A/C pump for OBA, generator, Saginaw PS pump for hydraulic steering. Still I have one pulley unused for a second hydraulic pump for the winch as soon as I get too it. They are mounted in 3-4 different planes, relative the fron of the engine, which means I have to find new pulleys, relocate all, but the crank relative the planes and find a routing for the serp belt and positioning of a tensioner and a few rounding pulleys. I just do not see how I can manage that engineering feat. Please help me along in deciding and if the serp front end is really worth all the extra effort I really need help in managing the positioning of all the pulleys! Tobias Quote Link to comment Share on other sites More sharing options...
Aragorn Posted November 1, 2009 Share Posted November 1, 2009 i dont know enough about the differences, perhaps you can use the serp casing but use v-belt pulleys? Someone else must have better knowledge of the RV8 front ends? Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted November 1, 2009 Share Posted November 1, 2009 OK There are 2 main types of front end Serp (mainly late 3.9s - 4.6s) and Non serp The front ends can be only retro fitted, ie a non serp fitted to a serp, as BBC correctly says with a Crank spacer as its too long you can't fit a serp to a non serp without major crankshaft mods as it too short, and non of the serp bits are a direct swap for non serp So, if you wnat to fit a non serp front end you'll need a complete front end timing cover, water pump PAS brakets etc to do so Starters are the same, manifolds on the 4.6s are pants as they crack, use 3.9s, as to the engine the colour around the rocker area is a good indication of a low mileage well kept engine , however finger nail feeling of a liner is not so promising Nige Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted November 1, 2009 Share Posted November 1, 2009 I'm running a 4.6 block with a 3.5EFI front end and 3.9 top & heads, just to be different although the 3.9 top is effectively the same thing as the early 4.6 top - same injectors etc. which is the same as the flapper, the flapper having the less nice injectors (the ones with tails rather than the ones clamped by the fuel rail). The later Thor top end used the same lower casting again although I can't vouch for differences in machining as I've not examined one closely. All the plenums are basically the same, all the throttles are ~70mm so there's nothing to be gained there other than the various versions of throttle cable mountings, idle air control, plumbing, etc. The pulley spacer goes between the crank bolt and the pulley, otherwise the nose of the crank prevents the bolt from gripping the pulley and holding it in place. Flex plate should interchange although there may be a dowel in the crank that fouls, mine pulled out with a pair of pliers but you could grind it down if it won't move. As for oil pumps - I really can't see there's much in it. I'm running the old style oil pump and apart from the well known need to prime the pump on first build, if in good nick they work fine. Certainly I wouldn't let choice of oil pump get in the way of your choice of ancillary drive. The really early (as in SD1 era) lumps had smaller oil pumps but that's going back a long way. The 4.6 heads were skimmed by a small amount to make up for the thicker composite gaskets, although there's so little in it it's not worth worrying about. I'm running 3.9 heads and composite gaskets, which technically lowers the compression, but it's not noticeable in practice. The only other thing that springs to mind is that you will need to swap the sump & pickup from the 3.5 if you use the front end from it as the sumps are shaped to the front cover and I don't believe they're interchangeable. Quote Link to comment Share on other sites More sharing options...
task Posted November 2, 2009 Share Posted November 2, 2009 About the front end. I really want the pulleys to be vee-pulleys, since Ive all vee belt ancillaries and built up brackets for all the ancillaries I want. I'd really not fancy nouting new ancillaries/pulleys to get it all working on seprentine. Esp. the york AC pump for OBA. Does the water pump for serpentine front end rotate in the same direction as for a vee belt system. I.e. can I run the serpentine water pump in the same rotation as the engine and just make up a vee belt pulley for it. The serp water pump operates in the oppisite direction to the earlier V-belt driven pump, hence the thread being handed differently on the viscous fan units pre/post serp. Quote Link to comment Share on other sites More sharing options...
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