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MG MGB Technical - Rebuild survey

I know there is a ton of info on rebuilds in the archives, but I wanted to get an up to day survey of what folks who did there own rebuilds used for pistons, Compression Ratio, Cams, lightened rods etc..
I'm going for a hot street motor, already have the top end done, but wanted to get a sense of what setups people liked for bottom end/cam.
Thanks
Bill
Bill Mertz

Ported head. ARP studs
Crane cam
Weber DCOE
Tubular header- switched back to original manifold.
Bored 60 over
Stock rods with ARP bolts.
Cast pistons (still 4 ring)9.5/1 compresion ratio.
Rotating assembly balanced (all of it)
Deepened and baffled oil pan
Full mechanical tach.
All rocker gear rebuilt with new bushings.
Balanced crank (flat style)

Results:

Starts and idles very well once it is warmed up. Spits and barks if asked to pull when cold.

The engine has the pull that I want, but it has never been good in throtle transition situations. I am not aware of any problems with the crane cam, but would not advise buying one because the manufacturer really has no interest in these cars and does not sell a "Kit" for the application. You will need a offset key to degree the cam and crane does not offer any for the job. Lifters are another sore area and crane has no solutions. There are suppliers who "speak" the MG language and are much more deserving of your money.

I bought remanufactured rods from Brit Tek, who I consider a great supplier. Unfortunatley (fortunately?), the last bolt I tightened broke. In went the ARP hardware for the bottom end. Do not trust used rod bolts in a modded engine.

Its been four or five years and the beast is hanging togeter together. No overheating or poor manners in traffic.

Pete
Pete

lightly ported head (a Burgess head would be best)
Piper 270 cam
Aldon "Euro" dizzy
stock HS-4s w/ K & Ns and short trumpets
Peco 2" exhaust w/ no center muffler
waisted valves w/ 3-angle grind
40 over forged pistons (4 rings)
lightened flywheel
Stock rods and balanced crank
new rocker gear and cam bearings
Short pushrods and bigger tappets

Great reliability
18,000 miles so far
Starts first time w/ choke
Nice idle

oil pressure:75 at start-up, 40-45 at idle hot, 60-65 at hot high idle

No overheating issues: Electric 12"Hayden pusher fan, fan shroud, 6 blade mechanical fan, 165 thermostat (in Miami, you know), 10 psi rad cap, 4 row modern rad core, later short nose water pump w/ cast impeller.

great pulling response in all gears
Wheel shrieking pick-up
Moves nicely when stomped on
Luigi

""" SUPERCHARGER ""
Ray 1977mgb

Pete, when you deepened and baffled your oil pan, did you modify the oil pump pickup so that it drops lower into the pan?
Bill Mertz

Yes the oil pickup is lowered. For mech tach in my above post read "distributor"! I really need to learn how to think and type at the same time ;-)

Pete
Pete

V8. :)
Carl Floyd

1971 18GK engine

Burgess Econotune head
.040" overbore
Stock grind Piper cam (provided by Peter)
Rods and pistons weight matched to lightest
Crank and all attachments (pulley/flywheel/clutch) balanced
18V style lighter (tubular) pushrods
18V tappets, hardness and dimension inspected
TR7 clutch disc
K & N filters
newly rebuilt dizzy set up for ported vacuum
1 1/2" HS4's

Starts up immediately, runs very smooth, revs freely, and pulls out of corners like a demon.



Paul K

MSX Pierce cross flow, ported by Peter Burgess, to "large valve,Fast road" standard; 1 3/4 SU; P185 with new Rockwell hard lifters; Jackson 1.55:1 roller rocks with tube spacers;60 over HC forged AE, approx10.5:1 CR; dynamic balance from lightened fly to harmonic balancer; Aldon "Stage II" dizzy with pertronix, Han's Pederson 2.5 inch tube header LCB , jet hot coat in and out to 2" Peco single silence @ tail, ARP top and bottom, uprate oil pump, road pressure 75-90, and idle 40-50, wideband O2,Ford Sierra close ratio 5 speed. Finally--- big silly smile when she jumps past 6500 RPM and is still pulling like a freight train. Vic
vem myers

I'm not much use to you since I rebuilt my engine pretty much stock (just .020 overbored and with HC pistons instead of the original US LC ones). But I would say definitely have everything balanced! That makes a big difference to how micely everything runs.
Simon Jansen

Vic,
Sounds like an awesome motor.
90 psi!!!! Wow.
Is there any risk to running that much pressure?
And is volume more important than pressure with the oil pump?
-Bill
Bill Mertz

Bill:

I also have the high oil pressure. Yeas there is a drawback in that the cam drive is likely to wear. Racers use a bronse bushing as sacrificial for this reason.

Pete
Pete

I'm with Pete, but run SUs, so a vacuum/mechanical distributor is a must. Also, lightened flywheel, roller rockers, light lifters/pushrods, JetHot header with 2 1/4" exhaust system, Crane XR-3000 ignition system, etc...

Supercharger? I wish!!!
Jeff Schlemmer

This thread was discussed between 11/05/2006 and 15/05/2006

MG MGB Technical index

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