FE-FC Holden Discussion Forum

Technical Board => General Technical => Topic started by: jimbo492 on September 19, 2014, 12:00:00 PM



Title: my blown grey
Post by: jimbo492 on September 19, 2014, 12:00:00 PM
Hi guys
Have enclosed some pics of my grey motor after assembly.  Rebored to 3 1/8”, new pistons, rings, camshaft grind, new bearings, heavy duty main bearing caps, line hone block.  Camshaft grind 30/70 new bearings, conrods resized, new bolts, new gudgeon pins, rods shot peened and balanced, new oil pump gears shaft and relief valve, lightened flywheel & surface ground, new timing gears, refaced cam followers, engine fully balanced. New pressure plate and clutch plate, Head 1 ¾” inlets & 1 ½” exhausts, Chev valve springs, seals, std. comp. ratio, 2/71 GM blower fully reconditioned in excellent condition, 2” SU fully reconditioned.
(http://i1373.photobucket.com/albums/ag395/bally/BLOWN%20GREY/RNL9TYV_zpsa6b31afb.jpg)
(http://i1373.photobucket.com/albums/ag395/bally/BLOWN%20GREY/RUBHJJ3_zps59777a01.jpg)
(http://i1373.photobucket.com/albums/ag395/bally/BLOWN%20GREY/RJL2JTM_zps48488f99.jpg)
(http://i1373.photobucket.com/albums/ag395/bally/BLOWN%20GREY/RHA2IL3_zps43b3fbd3.jpg)
(http://i1373.photobucket.com/albums/ag395/bally/BLOWN%20GREY/RUXLEV2_zps457654d2.jpg)


Title: Re: my blown grey
Post by: john253a on September 19, 2014, 12:30:54 PM
Deff looks the goods
And should make a good clean 1-120hp no problem
Did you do a bottom end stud girdles and windage tray


Title: Re: my blown grey
Post by: Harv on September 19, 2014, 02:52:58 PM
Love this thing  8).

Looks to be about 1.85:1 drive ratio, which is pretty quick for a Roots. Probably won't detonate the blower (anecdotally they should be good for ~14000rpm, or 7600rpm at the crank on that drive ratio... 7600rpm at the crank is pushing it for a grey, short of the forged-crank specials). However, it's hard to judge how it will behave. It may run out of puff - in their original use the blowers were operating closer to 2000rpm. In this case, even though you are spinning the crap out of it you may still just get "normal" bosst of 10spi or so. On the other hand, if the internals are tight it may generate a crapload more boost than you are anticipating (in theory up to 50psi at that drive ratio on a relatively standard grey). I'd be pretty cautious on startup, watching the boost gauge really carefully at anything above idle. You may be able to drop the pulley ratio (and lower the blower stress) without losing much boost. The 2-71 has 136ci/rev, compared to a Type 65 Norman (typical grey motor blower) at 118ci/rev). This means you could run it a poofteenth slower than the Normans, which normally run close to 1:1 at 5-7psi.

I can't see a relief valve in the picture, though it could be hidden by the camera angle. Definitely needs one, especially if it is wizzing around at those speeds. Anyone doubting the need for a relief valve should watch this: https://www.youtube.com/watch?v=Ll3EvNMBgLA.

The 2" SU should be fine - good choice.

I'd love to see how that crankshaft pulley was put together - looks like a gilmer pulley bolted onto the aftermarket harmonic balancer, with three extra holes drilled to give a total of six bolts.

The breathers on the rocker cover look cool.

Gary - if you're reading this, we may need to make up braces from the top of the cylinder head to the manifold, similar to these ones, at some stage.

Cheers,
Harv (deputy aprentice Norman supercahrger fiddler).


Title: Re: my blown grey
Post by: NES304 on September 19, 2014, 02:53:09 PM
Wow!


Title: Re: my blown grey
Post by: jimbo492 on September 19, 2014, 03:04:51 PM
number 2&3 main bearing caps have strenghtheners


Title: Re:
Post by: GreyFC on September 19, 2014, 08:46:36 PM
Possibly the greatest thing I have seen on this forum.


Title: Re: my blown grey
Post by: fcwrangler on September 19, 2014, 09:43:11 PM
That's one sweet looking unit, don't suppose you have a spare lying around?
Jim


Title: Re: my blown grey
Post by: jimbo492 on September 20, 2014, 02:09:10 PM
hi guys here are some pixs of bearing caps(http://i1156.photobucket.com/albums/p576/anjimba/bearing%20caps/holdenblock002_zpsea01e875.jpg)

(http://i1156.photobucket.com/albums/p576/anjimba/bearing%20caps/holdenblock002_zpsea01e875.jpg)


Title: Re: my blown grey
Post by: jimbo492 on September 20, 2014, 03:15:01 PM
  Hi Guys
  Here are some pics of the bearing cap straps being made(http://i1373.photobucket.com/albums/ag395/bally/BEARING%20CAP%20STRAPS/P5020370_zps0d16ca47.jpg)

(http://i1373.photobucket.com/albums/ag395/bally/BEARING%20CAP%20STRAPS/P5020371_zps90e9dd88.jpg)

(http://i1373.photobucket.com/albums/ag395/bally/BEARING%20CAP%20STRAPS/P6170378_zps540f58e5.jpg)

(http://i1373.photobucket.com/albums/ag395/bally/BEARING%20CAP%20STRAPS/P6170377_zps86eee667.jpg)

(http://i1373.photobucket.com/albums/ag395/bally/BEARING%20CAP%20STRAPS/P6170379_zpsacfbd617.jpg)



Title: Re: my blown grey
Post by: Gary C on September 21, 2014, 10:49:08 AM
Gunna be great to hear this running!

I also would like to know what you did for the crank drive, looks like a ross ballancer?

I put a relief valve on mine and when you hear it have the odd sneeze/cough when starting cold you sure do shit yourself!

Looks great, top job.

Hope the su clears that bonnet!

Gary.


Title: Re: my blown grey
Post by: Harv on September 21, 2014, 10:57:28 AM
I put a relief valve on mine and when you hear it have the odd sneeze/cough when starting cold you sure do shit yourself!

The 30/70 cam has increased overlap from the factory 10º to a whopping 100º. Pretty good chance that this thing will sneeze like it has hayfever from idle up to mid-range.

Big overlap + 80% overdriven + positive (gilmer) drive = relief valve definitely needed.

Cheers,
Harv


Title: Re: my blown grey
Post by: jimbo492 on September 22, 2014, 01:08:39 PM
the balancer is stock standard balancer & rubbers of an FC grafted onto a aftermarket pulley designed to accept a blower drive pulley. cam specs. are inlet opens 28.86 BTDC & exhaust closes 30.72 ATDC. It has a cam overlap of 59.58 degrees. This is the recommended cam for my boost by SURECAMS who ground the camshaft.The pulleys are 6K polyrib the ratio 1-18 :1 which is 18%overdrive. There is a backfire valve below curved inlet tube with an area of 5.3 square inches. Apart from the blower drive system & the cam grind this is the same setup used in the early sixties with sucess. regards jim


Title: Re: my blown grey
Post by: Harv on September 22, 2014, 02:19:05 PM
Thanks Jim - good info.

I was assuming 1.85:1 based on measuring the photos - looking at the two pulley diameters like below:
(http://i929.photobucket.com/albums/ad136/V8EKwagon/pulleys_zps7658f265.png) ($2)
I guess the crank pulley (bit the belt runs on) must be a lot smaller in diameter than the outer hub face. 1.18:1 sounds a lot better.

You're right about the overlap too (my error... not enough coffee) - 60º. Still a fair increase over the factory 10º, and will drop around 25% of the boost pressure. Looks like the design (large blower, overdriven and highish overlap) has been set-up to purge-fill (blowthrough) the cylinders. At low rpm emmissions will be a bit high, though will get better at higher rpm.

5.3 squinch is a good sized relief valve - bare-minimum of 2 squinch on a grey, better off at 4 squinch and 5.3 is better still given the blower capacity.

Can't wait to see this thing fire up.

Cheers,
Harv


Title: Re: my blown grey
Post by: ACE on May 23, 2015, 08:21:42 PM
Thought i'd bump this for jimbo492 who is now selling the engine.
ACE  8)