BritishV8 Forum

Nic and all, I hope we're not," mind propagating", this just so it will look cool? Form Fit and Function-Nic,"focus". Are you strokin to the beat of a "Medusa Motor" in that Vega? I feel slideplate/port injection best, in leiu of blower- maybe later. I like a 3.3" stroke with 2.1 journal and larger fillets, strong. Enough torque and lots-o-rpm. I'm tryin to track down  the rear drive poly vee set-up on  some Eaton blowers usedon Buick V6's. Anybody? Might make for a really short motor. So, consensus time, I think I can bolt-on .75" thick deck plates-no welding, but will need "long" liners and rods= wider/taller motor or weld-on head adapters with std. deck height? I'm leanin, the std. deck as I have no qualms of welding the block. Rotus Marathon V8  ?

Art, for your cam tube replacement, I've run some quick math on that, but first, a couple thoughts. If you go that way you can plug the left side galley with a nearly full length rod  or tube to isolate the main runners. This can be aluminum. The use of low temperature brazing rings and flux in strategic locations on that rod and the cam tube would allow you to seal and bond to the block via oven braze without the hazards of a tight press fit. But the down side is that any way you do it, it's going to be costly. My business is prototype development so I have a pretty good idea of what I'm talking about here. All of the machining operations add up quickly, and so does the planning, layout, and assembly work. That precision step-ground, index-relieved, and keyed/ported tube is going to run right around a grand to make and more for the precision install of that and the plug, and more for oven braze. By the time it's finished, expect to have $1500 at least in that modification. Feel free to get a second opinion. If you can find somebody to do it I really expect your cost to be significantly higher than that. Also, the wall thickness on the tube is going to have to be at least 1/2" to allow adequate reliefs to be cut and leave enough wall to hold pressure. Remember, should you decide to stroke it later there will be no taking it back out for deeper reliefs and cutting them deeper in place would be horrendously difficult and therefore expensive.

That rear engine idea has some merit. For years I wanted to build a Manta Mirage, but just the same old SBC engine seemed somehow.... well just not in keeping with the uniqueness of the rest of the car. Chances are I'll never do it, but if I did, this engine might be more in keeping with what would be appropriate for that one. A basket 'o snakes out the top of that car would look quite appropriate!

Jim

Good point, Art. I'm beginning to stray here. I really started this thread to "enable" you. I REALLY want this engine to be built. I thought if we had a way of spreading out the concept phase across some good minds it was more likely to happen. I was hoping this forum would be here as resource to facilitate your process. Hopefully get some idea from it.

I'm going to continue to assume that you are going to build this engine. With that in mind. Have you purchased the heads yet? Maybe I could help with that when the time comes. I can look around for the poly vee rig from a SC Buick V6. I'm just saying I'm on board with this project. I'm a computer animator now but before that I did other things:

I was a tool maker and I worked with a contractor to build die sets for production of Molex connectors. We made parts the old fashioned way. Mill, heat treat, surface grinder. Every part was made this way. I got a lot of part fabrication experience that way. Not much help at precision fabricating because I don't own the tools for it. I might have access via some friends. I haven't TIG welded yet but I'm willing to learn stuff.

Before that I rebuilt WWII aircraft engines with a small company called JRS Enterprises. I mostly worked on the Wright 1820. I also worked on a racing Merlin V12 for the company's Reno project called "Tsunami". We ported the intakes, added nitrous injection and adapted super coils from a couple GNX systems. At the end it made 4200 hp.  FUN!!

Back on topic here. Jim, I thought your idea of boring all the journals to the same dia is a good one. That would reduce some complications with adding the Cam Blank. On the other hand what about using your stainless steel sleeve idea on both galleries. Feed both of them through the front of the block. That would simplify things a bit, wouldn't it? Then just redrill from the main side to regain access to the galleries. Then we wouldn't have to worry about cross over at all.

On the deck plate. Hmmmm. I'm not a fan but it may be necessary if we can't find a good way to install the heads on the block. It looks like the bolts are placed wider than than the buick by about 1" or something based on that pic at the top. 1/2" out from each is just about the edge of the block casting so it could be you just have to weld some extra metal on the edge of the block on both sides and it could be it'll work out just fine. Art, do you have a bare Rover block or head laying around? What's the distance between the bolt centerlines across the deck? It looks like about 2 7/8" or something like it. The Rotus head looks about 3 7/8". (total guess on my part). That's if the bore centers are indeed the same 4.24" on both heads. Any confirmation on that?

Nic and all, back to your earlier post. It's much easier to move bolt holes in a deck rather than a head, especially with all the parts in a 907. Bore centers match. I'm leanin the standard deck height for fewer special parts like liners and rods and more compact. I haven't verified if wall thickness of block if it "follows" the stepped-smaller cam journals. If so, this mod would weaken the block.If wall gets thicker towards rear, this would  also be a good mod for serious push rod motors, allowing .12" larger base circles and resulting stronger cam. I want to add strength not detract. Reason on rear driven poly vee on eaton is a generic solution for a rear drive system for many applications, pumps,dist. etc.? I have (4) heads, bigger valves, springs.I believe Lotus head bolts just barely outside of Rover, shear vs. flexure. Standard base circle on "original" 907 cams are 1.21".Lots of room for adequate lift. Because of work involved, motor needs a serious build to justify. I.E lots of hp., like over 500  n.a.? One could peep some data on 907 from Wikipedia or JHPS. Thank You all for input, roverman.

Ok. Can you talk more about the rear driven accessories. Are you saying off the back of the block? Or the backside of the timing belts?

Nic,It's just, rumor search at this point but "Superchargers and Accessories Inc.", says  there are rear drive M90's,( I have one), I need to send them a picture of it. Uses a drive shaft driven, "somehow" off of cam/sprocket. I have no more data at this point. I like the idea as a rearward accessories drive system under intake manifolds. We shall see, roverman.

One of the Caddy's had a carbon fiber shaft which was driven off the accessory drive at the front of the engine. It ran alongside the blower to the rear where it was connected in some manner, I suspect with a small belt. Looked pretty trick but I really didn't see the point.

Jim

Nic.. if I undestand you right you are looking for the distance between the head bolts? They are like 4 1/2 *3 1/8 on my 300cui... Have you considered any other 16V head?

No. you got any ideas? You're saying the two sets of five head bolts are 3.125" apart, right? That would make the Rotus head bolts at about 4.25" apart.

Art does this jive with the dimensions on your heads? Thanks man.

I saw a racing mod that put the alternator on the drive shaft back at the differential. That would leave only the oil pump off the timing belt of one side. Not a very practical solution for the street.

Nic. Yes the two rows are about 3 1/16 - 3 1/8 apart, and the row of five holes has a total of 17 inches in length.

I am inquiring about Volvo's B234 head in another forum to so what the split is between the head bolts, but no answer so far. They can with some work support +300 hp in a N/A 2.5 liter streetable version. They are used on one of Ford's fourbanger in performance applications. Initially developed by Cosworth and fairly available too on both sides of the pond.
Another head that perhaps could be feasible for this setup is SAAB's 16v, but I do not know anything about it more that it looks similar to Volvo's head.
If this works, do you think the bottom could handle +2000 hp turboed? I can imagine some racers wanting to do this kind of setup back in Sweden then....

I thought that one of the assets of the lotus heads was that you can drive the cams from either end of the heads, most twin cam heads would not allow this ,which makes life somewhat difficult in an engine in a V configuration.

Kevin.

Yes, would'nt it be great to find a cyl. bore spacing, webb -site and bolt patterns for 2, 3,4 valve heads? Until that happens, it looks like we got hard way. Interestingly enough, It was Charles Pinion of Real Steel who metioned about 25 years ago,(rumor) of using Saab 4 valve heads on Rover. 907 head is all that I've been able to find with correct bore spacing-kind of important. Yes, it's ancient, it's difficult, we haven't "seen" it taken beyond discussion. It's no wonder I'm drawn to the project like a self-imposed Purgatory. Perhaps I've"bad", in the past and this could be sentence? roverman.

Oh, undoubtedly Art, it's Karma right?

I had another look at the 215 block and there is an oil passage over the cam in the front to tie the two galleys together. Don't think the 340 has that but can't unbolt it just yet to check. Maybe in a few days. The 215 is drilled down to the front cover from the top and plugged, the 340 is drilled up from the bottom and gets a sender screwed into the end of the hole.

Jim

Ok, How to move the head bolt holes and keep it strong? Light went on and said- alum. billet, "npt". plugs, say 1/2"-3/4" dia's., to be determined. Machine npt. in deck for adequate clean-up relative to Rover bolt hole, scew in plug real tite and weld on top. Definately will be decking after all welding. Will be using studs in dry holes. Thoughts? roverman.

It SOUNDS good. Did you confirm where the bolts go on the block? Is it at the edge of the block like I was guessing? I'm just wondering where they go.

Thanks Art!

I calculate 1.062" greater between centerlines.  I plan to profile machine periphery of decks for a precision fit of head adapter plates. This "may" allow getting a stonger clamp package. Back to lifter valley stresses, even though we take the "tonage" of valve train stresses away, are there not substantial tensiles applied from combustion pressures? Possibly as high as 1,000 psi when plug lights? Spoke at length with," West Coast Racing Heads" today. "Richards" 2.3L.makes 270 hp at 7k and revs freely to 8,600. He took (1) lb. off of rod,pin,piston over stk. 907 parts.12/1 comp. on gas using ported 907 heads and 48 IDF webbers. Reportedly much better torque curve than stock S2000 engine.Lotus 912 heads have measurably larger ports std.vs 907. Reportedly, some motors are getting boosted to 40 psi-short term.They haven't worked on Volvo B234 head. roverman.

Just measured "Volvo". (2) center cyl's are fine, end ones aren't. End cyl's are 4.125" centers. Too much off-set to be viable. Perhaps it's fitting that a British head,(907/912), winds up, "Hot Rodded" onto a Brit. block.  Would be good to hear from someone who has max-ported or cross-sectioned a "912".What if Lotus, tranverse bolt distance was enough to, "stud" outside of deck, into main girdle outboard and cam repacement plug on inboard?? I shall investigate. If so, Mega Boost? Ford raw forged crank? roverman.

The 912 head looks very similar to the 907 head. What's the difference? It looks like you can't flip the cam cogs around...

I'm confused by the Main girdle stud idea. Are you saying locate the studs in a main girdle plate or something?

Nic-all. 912 has bigger ports std. Cam towers should reverse like 907. No word if 912 will port further than 907. "If" bolt holes can be moved further apart-tranversly, this would possibly allow use of studs thru heads, external of Rover block, threaded into, wider than pan rail,main girdle and into thick-wall or solid alum. cam replacement plug on valley side. This could really tie-it-altogether for some serious power loads. If by "cogs", you mean belt pulleys? I believe their on center? Lets remember,driverside head is already forward(.842")= rod thickness. This helps getting belt #2 over there. So far, this looks like only heads to go with. Thanks for the intrest, roverman.

Shame these wouldn't work for you:

http://forum.britishv8.org/read.php?3,8505

Greg

FWIW, OS. int.@1.45",67grms.,3.3sq.in(both). OS. exh.1.282",60grms.,2.58sq.in.(both) Bucket 1.375" dia,52grms. I think when you crunch the math against 2 valve set-up, one might see some advantage.Even if 2 valve areas' were equal, 4 valve would likely out perform on street use,(port velocities/flow under the curve=torque ), with given stroke. Yes the impressive, Ford, D3 head flows BIG numbers, but in Nascar it runs 7K-9300 rpm? Were this head scaled-down to fit 3.7" bores, how would it stack-up? Let the Dyno sort it all out, roverman.

Anything happening here, Art?

Not much.Manton Engineering has Rockwell Tester , but only Diamond,("C" scale) tip). I will likely need ball,(brinell scale) for camshaft. What's your final thoughts on cam/lifter, blank-off? Should you decide to build a 4" bore, Bulbous Rotus Brossum, on Miracle Grow......? roverman

I think it may be necessary with the 4" bore to have better support through the cam journals. Is there a reason not to just weld the blank in instead of trying to do the cold fusion press-fit thing?

Nic and all, I see "sensible" amount of interferance fit as a good thing(.001-.002"). Preloading the valley area and then welding-even better. To install, merely freeze plug and preheat block(2 Walmart electric burners will do), drop in plug vertically and its in.I would also pre-heat prior to welding but keep the welding temp down, so you don't loose your  press fit. Of course with a 4" bore, an integral deck plate will contribute strength while allowing favorable rod ratios with longer strokes, and possibly external studs?roverman.