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304 VT 304 Engine Rebuild (Supercharged 355)- For AC Cobra

WilloA

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Have AC Cobra (replica),

Current Motor VS 304 with,

Tremec TKO II 5 Speed.
Twin plate high perf sintered metal clutch
Vortech SQ-2 Supercharger - Running about 9 PSI.
Front mount intercooler
Front mount oil cooler
Mandrel bent ceramic coated headers - 4 into 1 - Active side pipes.
MSD Elect ignition & blaster coil
Etc etc..
Pretty sure it has stock internals though..
Apparently 410hp at the wheels.. I think this is a optimistic dyno reading..

Just purchased a 304 VT engine (roller cams), pulled it apart last night, looks like it has,

Yella Terra Roller Rockers.
ACL forged pistons (Seems to have stock crank and con rods though).
After market cam (not sure exact type)..
Starr 90mm throttle body / manifold.

The current plan is to rebuild this spare VT engine with 355 stroker kit, then stick on the supercharger (Vortech SQ-2), and put it in the Cobra.
Car only gets driven on weekends (when the weather is nice), so doesn't see many KM's, but still keen for reliability (not overboard), I only want to do this engine re-build once..
Keen for about 600hp.. Which is probably overkill for a car that weighs 1050kg, but......

Questions,

SCAT / COME / HARROP stroker kits - what is recommended (reliability for street use)?
What else should I look at that would not be in the stroker kit?
Compression ratio recommended for 355 with 10- PSI?
Will the Vortech SQ-2 running 10 PSI be sufficient for the 355 stroker?
This is my first attempt at re-building an engine.. So more questions to come..

Cheers,

Adam
 

immortality

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All 3 brands are good for reliability, it really comes down to how much you want to spend.

Price wise, the scat crank with Holden journals will do the job just fine but use good quality pistons. VT block should be clearanced already to suit the stroker crank, it just depends on rods you use.

For reliability, stick with a hydraulic roller cam. Because your using the supercharger to make the power you don't need to rev it to hard so no need for a solid roller cam.

Your best bet would be to talk to a reputable engine builder who can see you through the whole process. Have a look on the Aussie V8 forum for some good info on building a Holden V8.
 

WilloA

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I want to spend the least amount of money possible to build a reliable supercharged 355 stroker engine for the street, I am happy to spend what is needed without wasting money on unnecessary parts, and over kill ridiculously expensive "race" parts.. Also not to fussed on expensive 'show' brands.. So tuff but reliable..

Got the cam out, it's a Camtech 2248 C 49907B 49903A 100 - Hydraulic roller cam
And crank is off a 308...

The 355 kits I see around range from $1,000 to $2,600.. With the supercharger do I need a $2,600 kit (forged pistons etc) to gain the reliability?
Plus about $350 to get the kit balanced..
 

immortality

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If the VS already has a roller cam fitted than there is no need to go to the VT engine as that is the only advantage really. You may as well just throw the stroker crank into the VS block. If you get the Scat crank with Holden journals than you can reuse your rods, get some pistons to suit and your laughing.

BTW, that power figure for the VS engine isn't unreasonable at all, centrifugal superchargers can make decent power with a few revs, fitting a stroker just basically means you will need less revs to make similar power. That is a decent size cam too, contact Camtech and give em the numbers above and they should be able to give you the exact specs on the cam, it's probably a custom grind to suit the blower.

I'd still recommend you jump on the Aussie V8 forum as they will be able to give you some solid answers/advice.
 

WilloA

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I thought only the VS III and VT I had the roller cam.

I was looking for a starr manifold for the engine in the Cobra, then found this VT engine with a starr manifold, and a few other mods (for not much more then the manifold on its own), so I thought why not just build up this, that way the car is not off the road for months while I work on the engine. Yeah thinking about Scat crank with Holden journals, reuse rods, and purchase some forged pistons (maybe ACL), and the Camtech cam, if it works, why not.

Yeah I will definitely check out the Aussie V8 forum.
 

mr j-man

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I thought only the VS III and VT I had the roller cam
Correct!

I just finished building my 355.

I used the holden journal scat crank, scat H beam rods and CP forged pistons....holden journals balance up nicer compared to a chev journal crank
there are better pistons than acl out there especially for some induction....id recommend 4 bolt mains too!

Theres a supplier called Precision International based at Willawong Brisbane PRECISION | All your engine needs

I sourced all my kit through these guys and saved about 4-500 bux rather than going through ebay an ****....ebay prices are bullsh!t nowadays, so do your homework and youll save $$$.
Do you have a builder in mind yet??
 

WilloA

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Cheers, will give them a call Monday.

I was going to build it myself (just get the parts balanced by a machinist).
 

immortality

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I thought only the VS III and VT I had the roller cam.

I was looking for a starr manifold for the engine in the Cobra, then found this VT engine with a starr manifold, and a few other mods (for not much more then the manifold on its own), so I thought why not just build up this, that way the car is not off the road for months while I work on the engine. Yeah thinking about Scat crank with Holden journals, reuse rods, and purchase some forged pistons (maybe ACL), and the Camtech cam, if it works, why not.

Yeah I will definitely check out the Aussie V8 forum.
My Bad, I thought you meant the VS had been fitted with a roller cam. Definitely go with the VT block then. That is a nice cam but not ideal for a supercharged engine as the lobe separation angle (LSA) will be to tight. Talk to Camtech, they may be able to regrind it for you or suggest a better grind. You'll only need to get the cam and not the lifters as roller lifters are reusable.
 
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