Building A Race Olds 215

Dan Jones · August 13, 2009, 03:34:03 PM

> The 2001cc-3651cc class seems to be the least restictive apart from the
> manifold.

I recommend that you have the heads and intake ported together.
I've flow bench and dyno tested several dual plane intakes and
they've all had 4 good runners and 4 bad. By cutting down the
divider and radiusing the port entries, we've made good gains by
bringing up the bad runners to match the good. Good is relative
here as even the best runners were still a restriction to the
heads. I'd be tempted to gather 2 or 3 dual plane intakes to
experiment on and dyno test. On one, I'd remove the divider
entirely, making it essentially a long runner single plane.
On another, I'd use the flow bench to work the divider and port
entry to equalize flow. Use a carb spacer, if the rules permit.

> The Buick 2bbl intake is very similar to the 4bbl intake. In
> fact it is quite possible it has the same runners and just a
> different pad for the carb.

I have both here and they are the same except for the pad
area for the carb.

> The Olds heads modified by Dwayne Porter have inlet runners 1"
> wide x 1.7" tall which is just a shade smaller than stock 300
> runners and for a 215 I feel are adequate, and the flow figures
> look encouraging.

Some additional flow numbers for consideration:

In the September-December 2003 issue of the British V8 Newsletter, Kurt
Schley reports the results of a maximum porting effort on a set of Olds
215 heads (the 51 cc version, casting suffix -746). These are the low
compression Olds heads which are going on a 289 cubic inch stroker Olds
215 (welded iron 3.75" stroke crank). The porting was performed by
Dwayne Porter (c/o Motion Machine 802-951-1955).

The article does not say what pressure drop the heads were tested
at but states the flow numbers were corrected to 28" H2O. This
means the heads were flowed at some lower pressure drop and ratio'd
by the square root of the ratio of the pressure drops. These numbers
are likely to be optimistic compared to flow actually taken at 28".
Valve train used:

Ferrea P/N F6223 (Intake valve for a Ford 2.3L), 1.74" head diameter,
11/32" diameter stem, 4.8 long, 0.4" tip.
Ferrea P/N F6224 (Ehaust valve for a Ford 2.3L), 1.50" head diameter,
11/32" diameter stem, 4.8 long, 0.4" tip.
Comp Cams valve springs P/N COM-901-16 (ouer spring with damper),
1.5" OD, 1.080" ID, 110 lbs @ 1.65" load at checking height, 290 lbs @
1.150" load at open height , 1.110" coil bind height
Comp Cams retainers P/N COM-743-16 steel 7 degrees lock angle.

The valve head diameters were reduced to 1.62"/1.4", so the stock valve
seats could be retained.

Test #1 Stock head 1.525"/1.35" valves
Test #2 Stock valves but full head porting, intake opened to 1.70" x 1.00",
30 degree back cut on valves, competition valve job
Test #3 As Test #2 but with 1.62" intake valves, 1.40" exhaust valves
(intake and exhaust backcut)
Test #4 As Test #3 but intakes opened to 1.80" X 1.00", fully polished
runners, guides streamline

Test #1 Test #2 Test #3 Test #4
Valve Stock Olds Ported Olds Pored Olds Ported Olds
Lift 215 heads 215 heads 215 heads 215 heads
(inch) Intake Exhaust Intake Exhaust Intake Exhaust Intake Exhaust
1.525" 1.350" 1.525" 1.350" 1.620" 1.400" 1.620" 1.400"

0.100 43 35 48 36 51 45 51 46
0.150 63 52 72 55 77 64 77 64
0.200 85 65 95 73 104 76 104 78
0.250 104 73 111 85 128 88 128 90
0.300 116 77 124 96 146 99 147 101
0.350 122 80 138 105 159 108 161 112
0.400 128 81 150 110 168 114 172 118
0.450 133 84 158 114 168 119 173 123
0.500 134 84 165 119 170 124 174 126
0.550 136 84 168 120 173 126 176 129
0.600 136 84 168 122 174 127 178 130

A local (St. Louis, MO) MGBV8 owner had a shop that is no longer in
business port a set of Rover 3.9L heads.

Rover 3.9L
Lift aluminum heads
Stage 4 Porting

0.200 96.7 80.1
0.300 143.9 106.6
0.400 177.1 127.0
0.450 180.6 134.3
0.500 181.0 139.7
0.550 181.0 142.8

My ported Buick 300 cylinder heads:

Valve Buick 300 Exh/Int
Lift 1964 ratio
(inch) aluminum (%)
ported
Int Exh
1.775" 1.5"

0.100 66 47 71.2
0.150 99 82 82.8
0.200 129 104 80.6
0.250 155 119 76.8
0.300 174 130 74.7
0.350 187 139 74.3
0.400 191 146 76.4
0.450 194 150 77.3
0.500 196 152 77.6
0.550 200 153 76.5
0.600 200 153 76.5

Flow numbers were taken on a Superflow bench at 28" H2O with a clayed intake
radius but no exhaust pipe. Heads were ported by Jon Carls:

JDC Engineering
711 Walnut
Minonk, IL 61760
309 275-2761 (cell)

6000 Series Ferrea Buick V6 Stage 1 valves were used. Intake valves are
part number F6238 (1.775" head diameter, 11/32" stem, 4.735" long with a
0.271" tip). Exhausts are part number F6237 (1.5" head diameter, 11/32"
stem, 4.735" long with a 0.254" tip). Intake head shape is a 10 degree
Super Flo. Exhaust is a 29 degree tulip. Ferreas 6000 Series valves are
competition parts suitable for solid roller cams. The larger valves
required larger seats, p/n 30903 for the intake and p/n 30647 for the
exhaust. I gave Jon a junk head to experiment on and he said he actually
pulled a bit better numbers on the test head. I can see spots where he
intentionally went through the aluminum into the water jacket. These
heads are destined for a street application, so it was important to leave
adequate wall thickness. An all out race heads would recieve more porting.
I'm pleased with the results. The exhaust to intake flow ratio is good
and the low and mid-lift numbers are excellent.

Pictures of the ported heads are shown here:

http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album10/album12/?g2_page=1
http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album10/album12/?g2_page=2
http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album10/album12/?g2_page=3
http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album10/album12/?g2_page=4

Do your rules allow the heads to be welded? If so, you might wish to look at
some pictures of a maximum effort set of Rover heads ported by David Vizard:

http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album10/album12/?g2_page=6

Be aware that the 2 barrel version of the Olds 215 came with large chamber
heads that would not be suitable for your race motor. The Two bbl heads
were suffix-746 and 51 cc's. The 4 barrel cars were equipped with suffix
-829 heads (43 cc's) or suffix -534 heads (38 cc's).

For your application, I'd be looking at running a flat top piston in a
zero-decked block with the 37 cc Buick 215 or 38 cc Olds heads milled
to a smaller combustion chamber volume. That should get you in the 13:1
compression range. An alternative to milling is to have the chambers
welded.

Come to think of it, what you really need is you need is my '62 Buick 215 heads.
GM cast a small batch (maybe 50 pairs) of the Buick 215 heads which combine the
small 215 combustion chambers with larger Buick 300 ports. These heads can be
ported beyond what a normal 215 or Rover head can but appear identical to a
Buick 215 externally and carry a GM part number. These heads were used by racers
like Mickey Thompson who ran a stock block Buick 215 at Indy in 1962 (qualified
8th with Dan Gurney driving) and Lance Reventlow who used the engine is his
mid-engine Scarab road race car. See "Souping the Special" here:

http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album10/album12/?g2_page=6
http://www.bacomatic.org/gallery2/v/hidden/dan/dan-cars/album10/album12/?g2_page=7

Dan Jones

Bill Young · August 13, 2009, 03:36:26 PM

Dale Spooner can be contacted at :

Motion Machine Inc
(434) 799-2604

560 Memorial Dr
Danville, VA 24541

castlesid · August 13, 2009, 04:09:52 PM

Hi Dan,

As usual, incredible information that will take my feeble brain a while to absorb.

No welding of heads is permitted.

Inlet manifold may be modified but no metal may be added.

I felt that the smallest chamber Olds 215 head with the more centralised valve would offer some benefit in the small bore 215 engine. would you agree with this?

If using one of the stock 2 barrel manifolds with mods, how limiting to power production do you think it will be.

Bear in mind that we are looking for the best stock combo to base the engine on the regs limit us to using the block crank rods heads and inlet manifold and 2 barrel catb which must all come from the same engine.

It is meant to be a low budget club racing series so you vcan understand why, but it is nice to find an edge!

If it's not rude to ask, how much does your head guy charge to do a pair of the big valve heads.

Yes your hybrid 215/300 heads would be nice, but I doubt that you would part with them for a figure we could afford.!

Regards,

Kevin.

Dan Jones · August 14, 2009, 01:40:11 PM

> I felt that the smallest chamber Olds 215 head with the more centralised
> valve would offer some benefit in the small bore 215 engine. would you
> agree with this?

The Olds may have slightly decreased shrouding but I like the Buick
spark plug location better and the chamber design rocks the piston
a bit less at TDC (not important on a stock stroke engine). All of
my experience is with the Buick and Rover versions so I can't say
much about the Olds. It may come down to which heads have the best
porting potential.

Do you have a copy of "Modifying GM's aluminum V8's"? In that publication,
the results of 19 separate dyno tests of both the Olds and Buick 215's are
presented. In stock 2 barrel form, the Buick made better power than the
Olds across the RPM range. The Buick also made the best power in modified
form but you'll need to closely study the results as those tests were not
necessarily on equivalent engines.

> If using one of the stock 2 barrel manifolds with mods, how limiting
> to power production do you think it will be.

What will your RPM band be?

> If it's not rude to ask, how much does your head guy charge to do a pair
> of the big valve heads.

My notes say it was $1050 for the Stage III porting. That included
the porting labor, flow bench and machine work, guides, seats, valve
job, etc. I supplied the Ferrea Buick V6 Stage 1 valves. To use
those valves you have to replace the intake and exhaust seats and
then port the bowls out to match the new seats. Also, to port the
bowls, the guides need to be driven out to make room for the cutter.

As soon as I'm done flowing the GM race heads in their baseline form,
I plan on taking them up to John for some additional porting (larger
intake valve). I think I have a 2 barrel intake and carb I could take
up to John if that's of any help. I could also also take a 215 block,
if he needs one to check valve to wall clearance.

> Yes your hybrid 215/300 heads would be nice, but I doubt that you
> would part with them for a figure we could afford.!

Yup, they aren't for sale :-)

Dan Jones

castlesid · August 14, 2009, 07:47:01 PM

Dan,

Well lets start from the first obstruction in the plumbing. If the modified two barrel Rochester can flow 500CFM and the manifold can be modified to work with that flow figure, what spec heads would we need to use that flow capacity and what RPM potential do you think we may get.

From what I've read it seems the 215 Buick or other versions can make good Peak power at approx 7250 RPM

The restrictions we have in that we must use stock rods and one of the stock inlets with a stock 2 barrel carb may limit the RPM limit that we can achieve, I'm also somewhat concerned about the safe RPM limit for the rods.which can only be deburred, polished shotpeened etc.

Clearly if our RPM goal is too high we would have to set the spec to achieve a lower peak power output at lower RPM's and sacrifice some power, what do you think?

Kevin Jackson.

BlownMGB-V8 · August 15, 2009, 04:32:15 PM

Kevin, the Olds Jetfire (turbo) engine came with the small chamber heads. These were nearly identical to the Olds 4bbl heads but had a different casting number and IIRC a slight difference in the chamber. Since that gives you the package of possibly a good 2bbl intake with the 38cc chambers it might be worth scouting around for one, or at least the pieces. That intake looks identical to the one I had.

Jim

castlesid · August 15, 2009, 07:21:47 PM

Jim,

Thanks for that.

Trying to make some sense of the of the likely operating range of the engine. I seems with standard rods and probably inlet we be limited to approx 6500 RPM so will have to sacrifice some ultimate top end HP but if we can make 250 + BHP I think it could be enough to make the car competive, the kit cars used are mainly Lotus 7 Westfield type copies weighing in at not more than 600 Kg/ 1320lb so will not be slow at around 425 BHP/Ton. Wish I was still young enough to drive one.

Kevin.

MGBV8 · August 15, 2009, 10:42:43 PM

At 7200, I wouldn't just be worrying about the rods. I'd be buying or building a block girdle like Repco did in hte 60s.

http://members.fortunecity.com/alicat1/bt19-1.htm

http://www.hotrod.com/thehistoryof/hrdp_0706_10_historic_hot_rods_performance_engine/ron_main.html

castlesid · August 16, 2009, 05:43:55 AM

Carl,

Block girdle is in our spec and I can get one without a problem.

Thanks for the thought though.

Kevin.

NixVegaGT · August 19, 2009, 09:51:28 AM

I'm with Carl the stock rods are great. They are forged and plenty strong for high RPM. I may retract my earlier pitch for the Olds heads based on the ability to port the heads. It's pretty obvious that the Buick heads have more to offer. The other factor is the ability to make higher compression with the Buick heads. You can get a bunch of power from the higher compression. That was a strong argument from Dan's position. I guess it comes down to fuel restriction.

With the girdle, the limiting factor for RPM is the valve train from a mechanical standpoint. I think you'll be covered there. Then it's just trying to get the intake to flow and avoid detonation at all costs. Do you guys use Ethanol over there? I suppose there is a fuel restriction too...

This is really fun.

castlesid · August 19, 2009, 05:01:11 PM

Guys,

The V8 has gone on hold for the moment as my friend has I feel sensibly, decided to do a season in a smaller engine class to get some track experience, but is still keen to do the V8 in due course.

So all your helpful information will go on file and hopefully we can pick this up again next year.

Many thanks,

Kevin.