P76 engine rebuild

boghead · Post by **boghead** » Sat May 01, 2004 5:45 pm

Hi all,
I have a 4.4 that is pulled down for a rebuild . The bores were measured and the engine shop said it would need to have a 20 thou bore.
I need a bit of advice on the rebuild and any advice would be a great help. I have a few questions that I hope that you can help me out with , They are... 1) What replacement pistons would be the best to use.
2) what cam profile would be best suited for this motor, It's in a 85 four door Rangie and it has a 5 speed manual box. And I won't be afraid to give it a bit of rev once and awhile.
3) Do the P76 heads need much of a port job to get them flowing?
And 4) would a 465 holley be suited for this motor ?
Troy

Bodge · Post by **Bodge** » Tue May 04, 2004 12:47 pm

You have so many options it really depends on what you are building it for and how much $ you have.

The P76 we raced has been heavily ported with extractors a litttle head shave and Mitsi pistons. Runs a Holly 390cfm [i think] on LPG yours is going to depend on what sort of manifold you decide to run. Lots of cam choices again motre about what you are going to do with it... Our one revs like the poverb and has plenty of power...

Try Ross Calgher - he is the man.

ROSS CALGHER MOTOR RACING
Automotive Repairs
Dynamometer Testing & Engine Reconditioning
Rover V8 Specialists
43 Princess Street, Waitara, New Zealand,
Ph 06 754 6582 Fax 06 754 6582 / 754 7505
E-mail rjcalgher@xtra.co.nz or autopro@clear.net.nz

boghead · Post by **boghead** » Tue May 04, 2004 9:37 pm

The Rangie is off the road at the moment for a rebuild- Suspension ,Body lift ,Bigger tyres (34" simex).Full paint job and changing the engine from a 3.5 (Major worn out cam) to the P76 motor.
All this on a limited budget . So I can't afford to spend too much on the engine side of things. I'm going to rebuild the motor myself (with help from some handy mates ) and was after a sort of combo that works pretty well without spending heaps of money.

Rangerat · Post by **Rangerat** » Wed May 05, 2004 10:26 am

Gidday Boghead

I'm currently building up a P76 for my Rangie.
To save yourself some money and time use the 3.5 heads (Cast, drilled and tapped to take the brackets for the alt, power steer etc..) the heads are the same as the P76. Make sure you use the P76 pushrods

Get some inlet manifold adaptor plates made up and use the 3.5 inlet manifold, carbs etc...
Use the 3.5 water pump/front cover then you won't have problems with the rad hose's going the wrong way.
All I'm useing from the P76 is the short block (minus heads)

Rat

Rangerat · Post by **Rangerat** » Wed May 05, 2004 2:38 pm

P.S.

I forgot to say - Make sure your heads are of a 81-85 3.5 also called the SDI. the valves are the same size as the P76.
Quickest way to tell, if your Engine number is on the side of the block (L/H side faceing up between the exhust ports) then it's the right one. If it's on the rear of the block (where the bellhousing bolts to) it's wrong.

Rat

boghead · Post by **boghead** » Wed May 05, 2004 9:21 pm

Hi Rat ,
Thanks for the info
went out to shed and looked at the differece of the two heads (P76 v's 3.5) the only difference that I could see was that the 3.5 head has 4 extra head bolt holes near the sparkplug holes. And the rocker gear is different, The 3.5 has shaft mounted rockers and the 4.4 are seperate like holden 6's. The heads that I will use will get hardened valve seats at the same time they will be surfaced.
The P76 inlet manifold is in pretty good nick and I was going to fit a 465 holley to it as I have one floating around here someware.
Can you see a problem using this combo?
Troy

Rangerat · Post by **Rangerat** » Thu May 06, 2004 2:54 pm

I see no problems with that combo.
2 things
1. make sure the valves in the 3.5 heads are the same size or bigger than the P76 (don't want to reduce the flow) and
2. the P76 manifold is not much good (flow wise etc.)

Rat

Bodge · Post by **Bodge** » Fri May 07, 2004 10:17 am

You guys should definitely check out willpower manifolds from Australia I think - made for the P76 ie no dodgey hard to seal adaptors... they are set up to take a four barrel carb - nice pice of kit - last quote $440 before the dollar went up.

I think Ross Calgher has them in stock but you can get direct...

Here is a comparison:
Original/Willpower/Buick 300

Rangerat · Post by **Rangerat** » Fri May 07, 2004 10:41 am

mmmmmmm

Single plane = top end power
Very nice but not quite what I want. Looking at increasing the low to mid torque.

Rat

boghead · Post by **boghead** » Fri May 07, 2004 1:06 pm

Great info,
I will measure the valves thanks rat!
I'll check into the Willpower manifold as the one on the Right looks good. It will depend on the price!!!
Do you run a standard manifold on the Bodge and is your 390 holley bolted with the bowl at the front or is the carby mounted backwards?
Troy

tomsoffroad · Post by **tomsoffroad** » Fri May 07, 2004 5:04 pm

Is this vehicle going to be used on steep angles? So far I have not heard anything good about using a Holley carb on hills. A few people have mentioned to me that they suffer from fuel starvation. I can't offer any advice from personal experience its just what i've heard.
Was talking to a guy last night with a Holley fed 3.5 v8 in a Rangie, he was saying that he had problems with the jets vibrating loose!!!
Why not inject it? :wink:

Bodge · Post by **Bodge** » Wed May 12, 2004 8:50 am

I run twin HIF6 SU's on an adapted P76 manifold on the Bodge. It runs on any angle. With the standard P76 carb it would die at anything over 10 degrees...

In the other rangie we ran a Holly with lpg - bowl to the front.... With LPG the fuel starvation becomes a non-issue..