Grey Motor Performance

[TorqueFC]

Hi Forum Members,

                             Over the last month or so we have been planning our next motor, as my car now needs a decent motor. We have had a talk with our head place who done the last head for us, and he told me to go do some research in regards to it. This week we will be pulling a set of 308 heads down to check out valve sizes. Below were some plans we were having for our head.

I dont know yet, but im thinking that the total size of a 308 standard valve would be shorter than a grey motor one or is it longer??.

If it is shorter, do you think it is possible to have the rocker posts machined down to the match the valves??

If the valves were longer, what could they do?, do you think they could modify the valves so the retainer is lower, then they just cut off excess??

What else can be done to the head??
on our other head we didnt do any porting, but it has now come to my attention that this is where grey motors fail??
and when they open up they breathe and rev much better?
what is the recomended amount to shave off the head??
may be a stupid question but the more thats shaved off, the higher the compression yes?

what other pistons are available other than the standard flat tops??,
when we rebuilt our motor we found all of the bearings were stamped 1991, so we never had to look into this. as for reboring, what is the recommended amount to take out of the bores?? i know usually they need to go so far just to get scores out, but is +60thou to much?? when at +60thou does overheating/cracking of the bores come into play??

the last thing would have to be the bottom end-which i think i will leave for another day as i would like to have a talk to a few mates  about what can be done.

with regards
Darcy West

[Glenn 'Stinky' Stankevicius]

When my 202 head was done many years ago, I was told to stick to relatively small valves, but open up the ports. The theory was that the ports flow better, but going through smaller valve openings increased the air-speed and hence more torque. When you have torque, you don't need to rev them as hard.
Anyway my valve sizes - Inlet 1.68, Exhaust 1.37.

[4hammers]

Torque,
The best valves to be used, are purpose built Grey motor performance valves. 202 valves are also good.
Remember Darcy, that if you want to drive this thing, it must be streetable. You go boring 60thou out & you will hit water. Open up the ports, get it flowing nicely. Don't go crazy with the head of compression, it will be a pig. Great on the racetrack, but not so good anywhere else. Like I said, my mate with the mega hot Grey, has got it spot on, but that cost him a LOT of $$ & I am not at liberty to give out all his secrets. Sorry.
Here is some info regarding cams & Valves I recieved to the following question.

Hi,
I have heard you still produce cams for the Grey motor. I am interested in finding out which would be the most suitable for my application & then purchasing some. I have been told the 30/70 grind is a good streetable cam as I will be running triples (1 3/16th SU's).  But also the 35/75 has come up as another option.  The motor will have the same stroke as the bore (the term
Squared motor has come up)with 100 thou off the head, double valve springs & will have Jack Meyer headers or extractors. Plus all the usual modifications to the bolt ons.
I have heard you sell cams on an exchange basis, but am unsure what this means. I don't have any Waggott cams to exchange, or is it standard grind you take? Also, do you sell the required lifters & pushrods, or can you let me know who does.
I hope you can assist me, as I am keen to purchase a couple of cams.
Regards,
Rob J

Rob,
We have been in touch with Waggott Cams, and Peter at Waggott has gone back through his father's records and has advised us that the following two grind profiles would be suitable for your application:
439    -    is good for road use , has a wide power band
212    -    more mid range to top end
When an item is exchange, it means exchange for standard, so in this case, exchange for a standard grey motor camshaft that is still suitable for a regrind ie the lobes must not be rounded off etc...
The other item we need to be aware of is the journal size -  over the last 50 years, engine reconditioners such as Repco and GEM Engineering (to name just a couple) etc... when reconditioning the grey motors they would machine the cam journals.  So we need to do one of the following:
-    make sure the cam we send away has the correct journal size to suit your cam bearings
-    supply cam bearings to suit your cam
-    have the camshaft(s) that you supply reground
The following information on the two profiles has been supplied direct from Peter at Waggott Engineering:
212
Advertied Timings
InOp BTDC    -    35 degrees
InCl ABDC    -    72 degrees
ExOp BBDC    -    73 degrees
ExCl ATDC    -    34 degrees
Timings At .050
InOp BTDC    -    7 degrees
InCl ABDC    -    44 degrees
ExOp BBDC    -    44 degrees
ExCl ATDC    -    5 degrees
Duaration
Advertised In    -    287 degrees
Advertised Ex    -    287 degrees
@ .050 In    -    230 degrees
@ .050 Ex    -    230 degrees
Cam Lift
Cam In    -    277.000 thou
Cam Ex    -    277.000 thou
@ TDC In    -    65.000 thou
@ TDC Ex    -    60.000 thou
Tappet Clearance
In    -    15 thou
Ex    -    15 thou
Lobe Centre
In    -    108 degrees
Ex    -    110 degrees
Group
A

439
Advertied Timings
InOp BTDC    -    36 degrees
InCl ABDC    -    70 degrees
ExOp BBDC    -    72 degrees
ExCl ATDC    -    36 degrees
Timings At .050
InOp BTDC    -    -1 degree
InCl ABDC    -    36 degrees
ExOp BBDC    -    42 degrees
ExCl ATDC    -    -3 degrees
Duaration
Advertised In    -    286 degrees
Advertised Ex    -    288 degrees
@ .050 In    -    215 degrees
@ .050 Ex    -    219 degrees
Cam Lift
Cam In    -    295.000 thou
Cam Ex    -    295.000 thou
@ TDC In    -    48.000 thou
@ TDC Ex    -    45.000 thou
Tappet Clearance
In    -    .012 thou
Ex    -    .014 thou
Lobe Centre
In    -    108 degrees
Ex    -    112 degrees
Group
A

We can not get brand new lifters or pushrods for the grey motor, as there is simply nobody making them any more.  However, we do have used grey motor pushrods in stock at $8.25 per pushrod, and we can get your old set of lifters refaced for you for $66.00.  We would need to know what model Holden the grey motor is from, as there are two types of rods & lifters for the grey motor - FX-FJ-FE-FC-early FB use one type, while the rest of FB-EK-EJ use the other type.

Kind Regards
Jaimie Norman



So you see, there are a lot of confusing numbers to consider.
Rob J

[TorqueFC]

wow, i know what you mean.

currently the motor that is now running in our ute just has 202 valves, 40thou over, shaved head,twin carbs, headers and below are cam specs

RUNNING CLEARANCE:IN   .14"     EX.014"
LIFT@LOBE:      IN   .296"   EX.296"

ADVERTISED TIMING
Exhaust opens:   75*  closes    41*
Inlet Opens:   40*  closes    75*  

.050" Valve Timing

exhaust duration:238*

SETTING SPECIFICATIONS
inlet lobe lift @ TDC on the overlap    .093"

the cam is pretty sweet, has a really nice idle, and it was quite easy to tune, havent had the car out on the highway yet so i dont really know how good it goes.

teh reason why i asked the above questions was because we want the next motor to be really really hot, and the car wont exactly be driven alot so you know-being a pig doesnt really worry me much  :-/

thanks for your help rob

regards
Darcy