13 replies to this topic

[boblhslr]

Hi guys in the process of building a 355 stroker. I've got to choose a cam for it. Just a little info on the engine. 355 stroker, Alloy vn heads, roller rockers, single plane manifold, 3500 stall and 9" with 3.5:1 ratio. Mainly street driven with the occasional run down the strip. Looking for a low 12sec car thats still not to bad on the street. Was looking at staying hyd flat tappet. Narrowed it down to 2 I think.

1. Crow cam 4802- i295 e295 @.050 i246 e246 lift i558 e558 lobe 108

2.Crow cam 4787- i284 e 295 @.050 i238 e246 lift i535 e540 lobe 112

Or do you guys have a better cam.

Thanks Mitch

[ozyozyozy]

Sends your engine and drivetrain specs to crow or crane, let them decide what would suit better.
Usually stall speed is dictated by cam specs.
The manifold may be too big for a most hydraulic flat tappet cams.

[TK383]

Go straight to a solid cam, hyd flat tappets are for stockers.

 

Maintenece is no biggie, check the lash every 5000K's or once a year, whichever comes 1st.

 

What heads are they?

Any port work done?

Compression ratio?

Headers?

What exact intake & is it port matched?

What rockers?

[Redslur]

I agree.  Go Solid flat tappet. Crane is my preferred cam range. I am currently using a Crane F280 and it will run high 11's low 12's comfortably in my 355.

[ozyozyozy]

I say hydraulic roller, good torque spread, no worries about rechecking lash or wearing lobes off.

[boblhslr]

Heads are procomp alloy's. Have some work done to them. 10:1 about. engine being built so can make compression to suit. Just a low rise open manifold. extractors and a 2.5 twin system with x pipe.

Was looking at going hyd roller was just a little worried about the gears for the oil pump drive and distributor gears. And the over all price of going to a roller cam and lifters.

Thanks

[TK383]

Oil pump drive is no problem, coated steel gear & it's all good.

Dissy gear has no load on it, can use any gear.

 

You can get Morel hyd roller lifters for around $650, they are ok up to about 6500rpm.

For roller cams it's worth paying the extra $ & going to crane, there are other companies doing holden hyd roller cams but I always use crane - quality steel cores, good lobe profiles & quality grinding.  A cam will cost you about $850.

 

Crane does a spring I really like for hyd roller holdens, it's a solid flat tappet spring with good seat pressure & moderate rate to keep nose pressure under control.

 

I build a lot of hyd roller engines for streeters, just finishing one today:

 

Scat crank & rods, Mahle pistons

VN heads with 2.02 & 1.625" valves, moderate port work

11:1 compression

Crane 244/250 on 108 hyd roller, .660" intake lift

Crane gold rockers

Harrop intake & QF750 carb

MSD ignition

Pacemaker pipes

 

Will make around 500hp & 450ft/lbs

 

I'd be wary of those heads, they are no better (some would say worse) than factory iron, QC is a real problem, guide & seat material is suspect even if you replace all the rest of the hardware & the castings are low quality alloy.

[LS1LX]

With any decent cam you will go 11s all day long

[gtrboyy]

Have you had anyone reputable check out those alloy heads? Poocomp manifold?

 

 

I've been looking on ebay at those $600 poocomp/atracing/sss heads wondering what they'be like for a junker engine build I'd like to do but deep down know factory iron head is best way to go.

 

Thinking of going there see if they sell bare head & allow hardness testing lol.

Edited by gtrboyy, 06 August 2016 - 02:15 AM.

[LS1LX]

I've seen those heads in action, the actual bare head itself isn't too shabby, it's the junk fitted that you need to throw away. A guy I knew bought a complete set and ended up turfing everything bar the bare heads, they owed him more than a set of come or Dave Bennett alloys. Still it did make just over 500hp at crank with crane 288

[gtrboyy]

Was thinking mainly for the weightsaving...we all know valves etc be throw-away so rebuild a bare alloy head with oem valves from iron head.

 

Only thinking about it as got enough leftover parts to build fun junker...low budget engine.

 

For a big banger I'd rather ported factory iron from blokes tk,hpe or  equivalent

[ozyozyozy]

Weight saving is huge, about 25kgs.
In most cases if your going a custom cam you will need valve tran yo suit that, so the parts supplied with off the shelf heads are wrong in most cases.
I have COME alloys and they wern't without issues too.
Wrong springs/retainers supplied even tho we gave them the details of what exactly was needed, pushrods touching and one hole on each end for ancillery bolt up was not a blind hole, went into the water jacket so had to seal it up.