I have just been buried....as I logged in to post a couple updates I see 6 months disappeared! Any way.....still very busy but I got a little more done on the V12. I finally popped the pistons out last night. I'd been putting it off because looking at the condition I was expecting a multi-day battle involving a big hammer and probably a chisel and grinder......so it was a very pleasant surprise when the whole process was over in under 1 hour with 0 drama After they were out though and I actually had a look at just how frail the rods and wrist pins are....WOW This all got me thinking a bit. I'd been going round and round thinking about having the stock crank offset ground since the journals are so large and it's SOOO much cheaper than having a crank made......but it kept bothering me that the factory increased the journal size in the later engines and the thought that un-standardizing is just NOT the ford way...so why do it? I'm pretty sure the answer is crank flex and grinding the journals smaller on purpose would be a pretty big mistake. I see the V8 guys do all kinds of girdling trying to stiffen up the blocks but I just can't see how the crank itself is not the bigger issue...the missing main bearing have got to be putting huge loads in the crank itself. Deflection is proportional to length ^3 and the missing or skipped main bearings means the bearing to bearing length is about 2.5 times what is would be on a crank with mains every throw.....and that means the crank will have about 15 times more deflection than if it had a main every throw. The solution is either add more main bearings or make the crank stronger by increasing the journal size and Ford chose to increase the journal sizes...... several times. In 36-41 they were at 2.125 42-48 was 2.25 or about 25% stiffer (it's diameter^4) 47-53 6 cyl got 2.298 or up another 9% from the 42-48 version or roughly 36% form the 36-41 version plus the mains went up too. I guess if I were going to make a crank I'd be looking at possibly using the 47-53 6 cyl design and I certainly don't want to go to say go offset grinding my crank to a 2" chevy bearing which is about 37% weaker than the 42-47 V12 2.25 journal I"m trying very hard to convince myself that I want to just use the stock crank and save a bunch of money......
I forgot the best part....or the worst part. The gick inside this engine is un-frikin real. Just coated with an oily-wax-tar that comes out in chunks...yuk! My hands will be black for a week I'm guessing.
Yeah...just busy. I emailed Scat and asked for a ball park price on a crank....you know...just in case. I was playing a bit today and my simulator keeps telling me this engine will respond scary well to a blower. My math is also telling me that if I'm redlining at around 4000....the stock portsat 1.3" are already way too big for what they flow.....flow area wise they are about double what should be needed for the flow numbers they are delivering I think......so I'm now wondering if I could inserts to split the siamesed ports and shrink the singles?...hmmmmmmm
Here is mine, I have a extra set of billet heads, 4x2 Ken Austin intake and N.O.S.(as in never bolted to a motor) complete distributor if you are interested.
Nice! I haven't decided what I'm going to do about ignition so I might be interested in a distributor at the right price. Heads I have and it will be getting a blower and I'm trying to figureout how to remove the 90 turn from the intake track so most likely a custom intake.
So here's what I get out of the simulator with a pretty mild build at 7 psi....300hp/400ft-lbs. This basically matches what I see quoted from H&H on there blower builds..they say 250hp but I'm pretty sure they told me 5-6 psi so I've probably got the boost a bit higher and I specd a smallish screw type blower spining fast not a biggish roots blower spinning slow.....so that is probably 50 hp the difference. But it looks pretty good for my application so I'm now really torn on how much effort to put in on the flow stuff.....some for sure but I"m not so sure about all my plans to split and fill ports and other assorted craziness. Know I want to hold the engine to about 4000rpm I did play a bit with options other than smaller port to help with that like pretty short duration cams but the best solution seemed to be a pretty small TB. This gets the torque dropping as it approaches redline which seems like a good thing vs pulling like a freight train until it bangs into the rev limiter.
For anyone intereste.....here's a graph showing a 1.6 liter/rev screw type blower compared to a B&M 144 roots blower. The green line is torque, red it boost . I played with drive ration to get the boot matched at my 4000 rpm redline. Notice there is a CLEAR winner performance wise.
The little 144 B&M was about the best of the roots....here what happens when a 671 is used. Again green is torque, red is boost, boosts are matched at my 4000 rpm redline.
RE: 90degree turns in intake; several years ago there was a VERY expensive(!!!) high-end flathead Bonneville-motor that had machined the as-cast valley ports away to re-configure the port openings to be 90degrees to the bore(makes the block resemble 2 conventional inliners conjoined at the crank) they plugged the exhaust ports & fabricated new intake/exhaust systems, now having much better access to the port/valve systems(I seem to remember this motor was turbo'd as well, just mislaid the Hot Rod issue to check) My thought at the time was(of course!!):"Why didn't I think of that?" :It was a classic 'outside-the-box' answer to a classic flathead restriction problem. drtrcrV-8
I played with the blower choice a bit more and it looks like I could go all the way down to about a 0.76 liter (autorotor2076) or 46ci/rev before the top end starts to really drop and the low end stops getting better.....this is a SMALL blower! but it really flattens out the boost curve.
Last set of graphs (I'm an engineer so you have to forgive me with the graphs ) Here's what an intercooler does on a 7 psi engine.....it drops the boost a bit. If you go back and change the belt ratio to get the boost back up there is a about a 10% gain across the board but for my application I'm not sure it would be worth the bother.
hmmm...it looks like the autorotor 2076 is a tough one to get these days. KenBell who was the autorrotor dealer started making their own units and autorotor folded and KB bought out the inventory KenBell's smallest is a 2.1l but thier price list shows AR1.33 as available, so maybe old stock Votec is now handling the lysholm line and can supply a 1.2 or 16. liter blower Whipple is making their own (they used to sell lysholm) and can supply a 1.6 liter I'll need to think...and actually put the engine together.....
I sent the whipple guys a note asking if I can get the compressor map for their w100 blower (1.6l). They are claiming 81% efficiency but it's a bit large so it might not be a better choice than the 1.2l lysholm which is only a 65% peak. I'm also seeing that for boost under 7 psi...the eaton roots blowers are pretty good and available in 45 (.73l), 62(1.0l), 90(1.47), 112 (1.83l)ci so right in the right range...the 62 was stock on buicks and generally cheap on ebay They also have a newer version (also roots) they call TVS which has a lot more twist in the rotors like the screw type blowers have and hits 76% efficiency which is a very good number....but the smallest I see at US dealers is 1900 which is a bit big. Eaton says they make a bunch of smaller sizes.....more emailing. On a past project I used the 112 eaton and it worked well at the 5psi I designed for but then I cranked it up to 10psi and the air was really hot! as the blower efficiency was only about 40% at that boost.. I l replaced it with a 2300ax lysholm and the temps were back down....then I added an intercooler cranked up the boost up to 24psi and life was good I'm thinking the M62 eaton is the right size and IF I stay to 5 psi would be a good choice and by far the cheapest option. 5 psi is a bit lower than I was thinking though.......
Oh...I see the M90 was oem on the later engines and also available cheap.....often under $100 with the TB and bypass valve So the M90 is another very cost effective choice.....graphs showing slightly better results are great, but saving about $1500-$2000 is probably worth giving up 10 or 20 hp.
Next thought. I can't get the simulator to even care about the porting on this engine....it's says there is plenty of air, but I'm using V8 flow numbers I found so maybe. I think I mentioned this before but it says at least 3 carb, 4 is better and that alone adds about 50hp. Then headers and free flowing exhaust bump it into the 180-200 range, right where I see numbers quotes so that all seems to match pretty well. It cares about the cams mostly in a bad way mostly with the V8 grinds all helping above my redline and hurting down where this thing will be running. I may see what can be done for short duration with aggressive ramps but...I' may leave it. I really want the blower on top but height is a concern. I'm going to make the intake and I'm thinking I can basically put a short stack on each port the open into a plenum....I need 1/2 for the stack, and I guess about 1" above the stacks, then lets say 1/2" for a cover plate because it has to have cool looking fins....so 2" the the blower at about 5.5".......that should be ok. The problem is I'd like to put fuel injectors over the port and that will force me to raise the blower at least another 1"...and that may force the blower to a side mount. All that planning the engine sh*t aside I'll need to sort out the piston, rod bore stuff. I can't really have the block machined until I have pistons. I can't order pistons because I have no idea what size the bores will cleanup at and haven't decide what to do in the combustion chambers I can't order rods because I don't know what size wrist pins to pick I guess I'll need to drag the block down to the machine shop and get it cleaned and have the bores cut but not finished. Then call the piston guys and see what they think about wrist pins and get something ordered to match the new bores, then I can call the rod guys, then pistons and block back to the shop. I guess....and decide what to do about combustion chambers.....
I'm supposed to be working on finally finishing the stupid ferrari engine and I did some of that last night but....I also popped apart one of the piston/rods and had a look at the combustion chamber on the lincoln. You guys used to this stiff know this but to me these look like 2 stroke pistons...they are so long. It's also surprising to me how far the wrist pin is from the rings.....it could move up 1/2" and cut 1-1.5" off the piston length....which of coarse got me thinking about stroke again now that I know for sure cylinder/piston wise I could add 1+" of stroke with no issue . Tonight I need to drop the crank back in and have a good long look......
I also took a quick look at the combustion chamber to start getting my thoughts in order. These heads have stock chambers, but the rough castings about 1/8" of extra metal on the deck surface for finish machining......but the surface looks pretty good and with a little press and tig work I'm thinking I can get them clean with under a .030 cut....so a net gain of about .095" -.100". I'm pretty confident that I could cut 1/8" into the chamber with no issues. I can fill anything I like with no issues. So what to do exactly.......... My thought at the moment is I'd like this build not to be the 6 year ordeal the ferrari build has become so I'd like to stick to known good options. Massive pop-up pistons have a race only reputation with pretty much everyone I've ever run into and while there may be a way to make them work on this build it just seems like way more risk than it's worth. Flat top pistons are pretty much the norm for the flathead world so I'm EXTREMELY tempted to fill in the chambers and use them. .....but I also know a lot of people have messed with this stuff over the past 80+ years and the fact that there is no "you must use this chamber" answer The hot head these days seem to be the Navarro with the 5/8" dome so I'm thinking I'll do something like that....and while digging though looking at stuff I found some so pics of performance model T pistons....which look suspiciously like the Narvarro design....and every old is new again I have to think its not quite as critical as some would have you believe but it does make sense to me that rounding the back of the chamber is going to make the air flow better and it is a well tested and proven design so I'm leaning heavily toward doing about a 3/8" dome. Right now the heads are at about .330...they will drop to .300 when I cut the decks then I feel good about going up to another .125....so .425" max
I couldn't help it....I had to make another gragh 4.5" stroker (light green/red) vs blower at 7 psi (dark green/red)....pretty much a draw.....but I know the blower is possible a 4.5" stroker crank in the block....I'm not so sure yet.
I had a chat with Jim at cunningham rods today $300 per a rod He was concerned about the 3/4 wrist pin and any plan that included using original type bearing inserts. I'm concerned what Lana's going to say when I try to pop a $3600 rod bill on her
What kind of details on the rods? Were they stock rods reworked OR completely new stuff? Wait till you get to camshaft stuff.
Yes, custom made. They don't have a forging with the 45 degree cap so the rods would be billet. It looks like Cadillac uses a 2.249 rod bearing that could narrowed to work on a -.001 lincoln crank. .....and there are mass produced 4340 H beam caddy rods at $540 per 8 that could have new small ends welded on to get the right length. This is a lot easier to do on I beam rods and clearly not as strong as a 1 piece rod, but still WAY stronger than the oem lincoln rods. These have straight caps though so this could only be done IF the pistons can be back loaded. This si an $1100 answer. I could buy a chunk of 4340 steel, setup the mill or call in a favor for some CNC time and make rods....which seems like a big pain in the butt.....saves a lot of money though as it would be around $500-$600 I guess for material, cutters and getting the big and small ends finish honed
Yeah...last I knew Web gets about $100/lobe to weld and grind to whatever spec, $60/lobe if it's just a regrind with no weld so $1500-$2500 depending. I don't see any need to do a billet cam for this build but I did have made billet blanks for the ferrari build....and then $100/lobe, (4 billets, drilled end to end, 48 lobes) to get them finished.
I talked to winberg cranks today.....they said plan on about $15k for 1 or $18k for 3.....who wants a crank? Right after that I called a buddy to inquire about CNC time......no problem so most likely the rods will be made there. IT would also be possible to rough out a crank I think then have it finished at a local shop that does a lot of heavy equipment engine type stuff and has equipment large enough for a job like this. I need to find time to get the cam out, clean up 1 bore and drop the crank and a piston/ron in and see how much room there is so I know its worth the both of trying to do a crank......
I just discovered this thread and wish I'd found it sooner. It covers a few subjects I'd also pondered while planning my most recent build - a blown, injected flathead V8 street engine. I'd read Joe Abbin's book about blown flatheads and gleaned lots of useful information. Joe does tend to use big blowers and drive them slowly. I wanted to use an Eaton M62 on my 250 cu. in. V8 but was defeated by the impossibility of mounting a crank pulley big enough to get the drive ratio I needed. I settled for an M90 ($140 from eBay) overdriven at 2.19:1 which gives me 6 psi boost. The injectors are in the valve chamber, squirting at the backs of the valves like any modern engine. I'd arrived at this position on another, unblown flathead, in which I'd originally placed the injectors vertically, squirting down into the port. I found that squirting the fuel at the back of the valve only when it was open made a big improvement in the way the engine ran at light loads and low speeds, especially when cold. It might not make enough difference in your boat application to be worth the trouble but for a street engine it is the bee's knees.
The Jalopy Journal
