BritishV8 Forum

Would this

   8514*    BLOWER - 215 OLDS 471 MANIFOLD, UNPOLISHED, 2 PIECE    $1,511.35
Fit a 4.6 rover block with Buick 300 heads, ? Or will I still need spacers ?

Bryan, how about a picture ? What is an 8514 blower ? I woudn't spend a dime, till I knew the port dimensions of the blower manifold. 300 head ports are approx 30% larger than 215. I modded an Offy single-plane maniflold, with a "Dyer Blowers" top half, to fit a 6V-71. This mated, with welding, to the Offy manifold perfectly. Rover and 215 deck heights, are the same. Good Luck, roverman.

Art, I did a quick Google search and came up with this link...
http://blowerdriveservice.com/cart/index.php?main_page=product_info&products_id=1028&cPath=64

Bryan, I've never heard of the company "Blower Drive Service" before. I suggest phoning them. I'd certainly be interested to hear whatever you find out!

BDS has been around quite awhile.

Jim

A little history,I've had supercharged Rovers for twenty years,3.5s 4.6 and for the last five years, a 4.6 with a one off billet steel crank,giving me 5.0L,
Steel rods,top hat liners,forged pistons,I've used what we call SDi heads,(3.5 ) ported,slightly larger valves,O ringed ,the bowls made larger to suit the larger
bore,roller rockers,the cam is a one off made to my own spec ! 114 lobe centres,4:71 GMC blower mated to a Elderbrock performer manifold.Holley 650cfm double pumper blower carb
On a dyno,it made 419bhp and 412 lbs of torque ay 5800rpm
I've now got hold of a set of 300 Buick heads,now before you all scream, get TAs, I'm going the tried and tested way of the bigger valves,and a good porting job
with these heads fitted,do I need a manifold designed for the 300 ?  Or will I be able to modify my existing ?
I respect your answers,as there seems to be a wealth of knowledge on here second to none
Bryan
Nearly forgot,blower is running 10% over,

Bryan, I'd say if you were pushing enough boost through a set of SD1 heads to get that sort of power then you will not be disappointed with the 300 heads. You can always consider the TA heads as a potential future upgrade. What vehicle do you run this engine in, and could you post a "How it was done" article?
http://www.britishv8.org/How-It-Was-Done.doc

I've run blown and boosted for 20 years now myself, starting with a modified Olds Jetfire and there are other blower freaks on here also so you are in good company and it's always good to see a new perspective. Where are you located?

Now as to matching the 300 heads to the 215 blower intake on the 4.6 block, that should not be much of a problem. Everything should match up just fine, the only issue is that the 300 heads have a little bigger intake ports. And I've forgotten how much bigger they are but there should be plenty of material in the BDS blower intake to port match. Of course, the step is going in the right direction (bigger ports in the heads) so even if you just slapped it on it'd work plenty fine, you'd just get a slight bit of turbulence below the step.

Since you've had your engine on the dyno is there any chance you have a dyno plot you could post? I'd love to see the torque curve with that setup. I'm guessing you are running about 8:1? What sort of mileage do you get?

I ran an Eaton M-90 on an Olds 215 for a lot of years, pushing 16 psi through those tiny ports but it gave me an entirely different view of things. Hopefully my M-112 equipped 340 will be back on the street this spring. It will undoubtedly satisfy my horsepower needs for quite some time. Details of that build are in the 340 thread. This page shows intake fabrication details:
http://forum.britishv8.org/read.php?2,274,page=10

Jim

Bryan, What is your intended manifold pressure ? I suspect with your latest build, a 4-71 will prove a little small. If you must run a GMC/Rootes type, a 6V-71 will make more boost, easier. What is your current boosted air temp at desired boost ? An M112 , like Jim is using or most centrifugals, will have much better efficiency. The Offy single plane, mentioned earlier, is quite easily ported to 300 size. Cheers, roverman.

Thank you for the quick replies , my scanner isn't working,so I photographed them !


Note,I was only running 5.5psi, spent a lot of time port matching
My car

In the UK we call them Populars,you call them Anglia's mine's 1954,had it 26 years
As it is know

New tube chassis being built

Yep. Blower Drive Service has been well known in the hot rodding circles for a long time.

Pretty impressive numbers, and a fine looking ride.
At some point I hope to get a dyno run and have them map the lower numbers. I really want to know what it looks like under 3 grand as that's where I do most of my driving, and so my builds have been shifted towards the lower and midrange. I'd guess your heads will shift things upwards a bit.

Jim

When I lived in SoCal decades ago, a friend of mine did all the polishing for BDS.

BDS routinely fabricates blower manifolds when none is easily available.  Their preferred method is to start with an Offy single plane dual quad intake, mill the carb flanges flat, and bolt/weld a thick aluminum blower mounting plate to it.  Since there aren't any readily available dual quad intakes for the BOPR, I don't know if they start with a single 4bbl intake or an EFI intake.

Any BOPR intake will bolt up if 300 heads are used on a BOPR, but the intake manifold ports will be smaller, so some port matching is required.

Using an oem./dual plane manifold, with a rootes blower on top, is a bad idea ! Distribution is all wrong, and full length of runners, are too small.If not using a BDS,= expen$ive, the Offy, NON dual port, single plane 4 bbl, is well suited, as previously outlined.  Onward, roverman.

The Offy dual-port (360*) works well for a blower intake once the dividers are removed. I built one that way for my Olds 215. Large plenum area, but you also have to remove the port dividers.

Jim

Yes, for 50cents/hr, one could do that, or just buy an Offy single port, for $2++ new ? The best part of the Offy single plane, for blower use, is it's nearly "all" plenum ! News flash, they have the 2x2bbl/large base, manifolds in stock. They are non heated around the carb. bases, making IDF Webbers, an easier option. This makes it well suited for a "Dyer" top piece, and a 6V-71. No Affilliation ! roverman.

Has anybody got a link for these  manifolds ?

" Dyers Blowers" and Offenhauser Racing, both have webbsites.  Cheers, roverman.

Thanks for the help,
I've found this

Could someone confirm its the right one ! Going to go bigger blower now

Bryan, The single port 4 bbl, is reportedly available in approx. 3 weeks, from Offy. I cut-down the central plenum divider to a max. height of appox. 3/8', with a 90 deg., inverted "^" on top, to better split the charge air/fuel. I think youll like the added boost potential, with less heating, from a 6V-71. According to Dyer site, this blower should produce 15 lbs boost @ 1/1 drive, on a 300" motor. Make sure you get the "large rotor one" !   Good Luck, roverman.

Bryan, 5.5lbs of boost at 10% overdrive, even on a 4-71,sounds "light" on boost. Could you post your cam spec's. ? Possibly too much overlap, is hurting your boost potential ?  Cheers, roverman.

The cam was ground at 114 degree lobe centres,
Duration @ 0.50 intake 234*
Duration @ 0.50 exhaust 244*
Lift @valve intake .488
Lift@ valve exhaust .510*

Bryan, What is intake centerline installed at ?  IMHO, this sounds a bit much, on the exhaust side, for a blown application. It's likely your cam and carburetion needs will change with the bigger blower, increased head flow, and more boost. I prefer using the bottom row of head "studs", as this is the weaker side of the head,(exhaust temp vs. aluminum). I would consider bolting the blower manifold to the China Wall, front and rear, to better stabilize the top end. This appears to be primarily, a drag car ? RPM drop, when it shifts ? Automatic ? Switching to a roller ?   This build would "like" E85 !  Good Luck, roverman.

Interesting. That's a significantly bigger cam that I'm using in my 340 but I'll probably be running higher manifold pressure. My specs are 212@.050" (262 adv.), .436" lift and 112 lobe separation. However, this cam is also noticeably bigger than the stock cam I used with the 215. It's a custom grind designed to give a wide torque curve and allow boost to extend the redline to 7000 rpm, without necessarily increasing output above 6 grand, while allowing spring pressures in the neighborhood of 110/260, which also allowed me to reuse my old Comp Cams single springs from the HiPo Buick 215 I originally had in the car. Also I am not shooting for a horsepower number much over 300 and prefer to keep the torque up, the static compression high, and optimize for economy. I figure the less gas it burns the more I can drive it.

From my 4 wheeling days, I was very pleased with the CC 268H cam in my old International Travelall 392 and liked the Schneider cam even better, but it did not have a blower. I'm not sure how that would have turned out with that cam.

I don't know if any of this helps but if it adds any perspective I guess that's good for something.

Jim

Thank you for sharing your wealth of knowledge with me,
Just found some more paperwork,when the engine was dyno'd,I had two pulleys with me,originally it was under driven,and the dyno result I posted up,was 1 - 1
Being a little disappointed,I took the blower and manifold to a reputable blower builder,my aim was to part exchange it,for a 6:71 !
I was talked out of it ! They checked my blower out,made me a new pulley (10% over) and built me a new inlet manifold.I haven't had this combination on the dyno yet,in truth I regret being talked out of the 6:71,
But on the bright side,bigger valve heads,bigger blower,hopefully a lot more power !
Not going roller cam.........yet, not sure of centreline


Point of interest,Farndons of Coventry(UK) used to offset the cranks for TVR ,making them 5.0L, I set up a meeting with the manager about making me a billet steel crank,when I got there,he had all the TVR drawings on his desk,so my crank is a tried and tested,but a forged billet steel TVR crank
Thanks for all the replies

Bryan, FWIW the BDS chart says a 4-71 should make 9.57lbs. boost @ +10%, on a 302" motor. Crankshafts are either "forged" or "billet", never both. If your crank is 100% machined, on all surfaces, it's likely a billet.  With a bigger blower and more boost, you "may" need (2) drive keys, on the crank. I would like a crank quote for either forged or billet. "Wildcat" is out of the question.  Cheers, roverman.

Cranks 100% billet,
I was charged £2k for mine,had mine cross drilled and knife edged.
Should have the car (and engine) back on the road,after 4 years ! Going to run it for the summer,while I collect all the parts,work has started on my heads,
Hopefully Offenhauser will make the manifold of which you speak
Many thanks for your help
Bryan