30 replies to this topic

[Orange SS]

I found a set of heads which I am thinking of purchasing for my 308. If anyone with experience knows could you let me know if these would be suitable for me. The heads I am thinking of buying have 1.94 & 1.5 valves and has been flow tested at 465HP and comes with a port matched strip master manifold.

 

My 308 currently has stage 4 heatseeker cam(good between 2500-6500RPM), edelbrock performer intake, pacemaker extractors, ICE ignition system, balanced & blue printed bottom end built to rev to 7k. Also running a reco'ed trimatic and 3.55 gears in a 9 inch diff. The heads I currently have while having bigger than standard valves they are nothing special in regards to porting.

 

Am I better off getting the heads I have done up to this standard or purchasing these other ones? The guy wants around $2000 ono for the BARE heads/manifold(comes with valves) so I would still have the cost of rockers & springs etc.

 

I guess I am after info on:

 

1) what it costs to get a set of early heads done up to flow 465HP - is it worth outlaying $2k just on a pair of heads?

2) What rockers would be needed as I need rockers which fit under the standard covers due to having factory air con in my SS hatch.

3) Will I see the benefits of heads that flow 465HP from the rest of the combo I have fitted to my Torana?

 

any info will be appreciated.

 

[Ice]

For 2k you should be able to get brand new alloys heads surely for a 308

[Orange SS]

Are they taller than cast heads?

As it is I can't even fit aftermarket rocker covers due to the aircon box being so close above the engine.,

[Ice]

That i dont know but more than likely

[rexy]

The Come heads are north of 3K.

[myss427]

Buy the time you buy springs, retainers and collets your getting close to aftermarket alloys which will always have a better port shape and be lighter and NEW! and you get high quality valves springs ect, and you know they work not someones word for it.

[Orange SS]

I want to keep the original heads as I dont want the cost of new extractors etc. I realise the money I spend on early heads could probably go towards the cost of the bits required to change to VN heads however I am limited mainly due to the factory air con and space under there doesnt even allow tall rocker covers to be fitted.

 

My aim is to have around 350HP at the wheels so if I am spending money on heads I'd like them suitable for this now. Heads and maybe a jump up to something similar to a stage 5 heatseeker cam should get me hopefully somewhere up over 300 and I may put a stroker kit in there if I am still after more power. If anyone has a heatseeker stage 4 cam, could you inform me of your power output? Or what else I should do to reach my target of 350 at the wheels?

[myss427]

350 at the wheels means nearly 450 at the engine, on a 308 you will need very good heads and at least 10.5 to 1 compression. Alloy heads dont have to be VN heads, you can get Yella Terra dash 11's that will do the trick. They are a B cast style head which you will be able to use your existing pipes and they flow more than 450 horses.

[Orange SS]

I realise the easiest way to get power in a 308 is to change to VN heads but I'd like to see what I can do with original heads but I am still weighing up my options.

I haven't bought those heads yet bomber. The figures he's stating may be something he's made up & I certainly wouldn't be parting with that much cash without proof of the flow. I've had the car 10 years now so there's no rush but I saw these heads come up & thought I'd get some opinions as there is a lot of knowledgable people on here & I am finally in a position where I can start to do the things I've wanted too.

What cam would you recommend to reach my target? I am once again limited to not being able to remove tappet covers to make adjustments to rockers due to the factory aircon box, so I think that means I have to stick with a hydraulic cam? (Please correct me if I am wrong, I'm still learning).

[Redslur]

Using a hydaulic cam and hoping for 350 RWHP is probably a big ask. I Had max flowed HQ style heads, a fairly decent size hydaulic cam, and all the other good bits and was getting around 290 RWHP.  A solid cam would have taken it over 300. So you may need to rethink your plans. Your goal may be achieveable if everything is spot on though.....

[looznugtr]

I second what parsons5000 said.

Speak with flowcraft. He can do it but may need more than a 308 with hydrualic.

I had a motor making 200kw wheels with 9:1 comp.

Cam was solid 272 crane.

This motor cracked in a LX Torana.

350 hp wheels is about 260kw.

your going to needs cubes (355)

Comp over 10:1 and solid cam with good headers and intake.

All up not cheap with a 308.

Get a ls1 into it they can pull 260kw rears with cam, headers exhuast and tune

 

[Rockoz]

With the horsepower you are aiming for from the 308, whats it going to be like to drive?

Probably not the type of drive you want if you get caught up in traffic.

But nonetheless it will be great on the open road.

Had 260 at the rears with my VE SS. And that was standard apart from the exhaust.

Great fun to drive.

That sort of power would be awesome in a Torana.

[Orange SS]

thanks for the comments! I realise I have more research to do - hence the reason for posting on here as everyone has different ideas and experience to offer. I won't be heading down the LS conversion path(as tempting as it is) so I might give Wade Cams a call and discuss my options.  

 

By the sound of it a stroker kit with heads may be the only way to achieve the power I am after which is what I had originally planned to do eventually anyway.

 

I have read up a bit about solid cams however I do not know anyone personally with one in their car. Could someone give me more info on how often rocker clearances have to be checked? Having to drop the motor to take rocker covers off is really too much work if this needs to be done regularly.

Does anyone know what roller rockers fit under standard height rocker covers?

[myss427]

The 308 in our A9X has yellow Terror -11 heads (B-cast style) Crane 288 solid cam, single plane manifold and 800 DP carby with 10.5 to 1 compression. Had roughly the power your trying to get and drove like a stocker untill you hit the loud peddle (fastest 308 I've ever been in). I don't understand about the rockers needing adjustment all the time, properly lashed it should only need checking every 20,000 or so K's, not a lot of work for the extra power.

[Orange SS]

I guess by stating the 350HP figure I just mean I'd like it to perform better than it currently does. If those gains are made by torque then thats fine.

 

In regards to the air con box - they differ greatly from heater box (as per the picture of my engine bay attached) so there's no way around dropping the motor to get at the rocker covers. If rocker clearances only need checking every 20,000kms or so then a solid cam option is a likely option as the car is lucky to do 5000kms per year.

 

 

 

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[purrlx]

Might be easier to change ac out to another type, open up whole new world of head engine combo's maybe ??