26 replies to this topic

[ACJ]

Hi chev400

Not a SBC but some of my thoughts.

I have just put together a Holden 355 hoping for 500 + HP.

I look at other car (in magazines) and if they all had torque power manifold and making over 500 HP it must be a good stare.

I wrote emails to companies like scat and crane cams, they are very helpful and this is some of there replies.

The best selection for your application is the Crane F-288 #883691 cam. This grind performs very will in 355 Holden's and has potential to make 500+ HP if the heads flow well.Attached is the cam card with all the relevant specs. Regards Jim Ioannidis Crane Technologies.

The 2-ICR5700-7/16 would be just fine and be the lighter of the two. The weight about 590grams, and will hold up to 500hp and 7000rpm.

If I could be of any more assistance please feel free to contact me by email or by phone at (310) 370-5501 and dial extension 121.

Thank you, Alex Gonzalez SCAT Enterprises.

Also bigger is not always better. I was very weight conscious with rods and pistons. Most people would just put I beam rod in but if you don�t need it the weight is just more stress especially with pistons.

To get the most out of the bits you get is very important, like making sure the manifold ports line up to your heads propel.

You are on the write track; gather all the information you can.

[myss427]

500 in a small block is very easy to achieve, good heads (AFR's) reasonable compression and a decent cam will make it easy. Reliability is what costs, the easiest way to get the horses is go the biggest cubes. That way you don't have to rev it so hard, why not go 400 cubes?

[yel327]

These go close as a crate engine:

http://www.summitrac...arts/EDL-46213/
http://www.summitrac...rts/PAR-3832SD/
http://www.summitrac...s/NAL-12498772/

This gets what you want: http://www.summitrac...s/MLL-PS4271CT/ , you wouldn't build it for that plus freight in Australia.

Or this is the ultimate (but not a small block):

http://www.summitrac...s/NAL-19166392/

[yel327]

I'd love that ZL-1 427 replica for my HK GTS327, but I don't want to spend that much. I already have a cast iron 454 block, crank adapter, forged 427 crank and L88 inlet manifold. All I need are some alloy heads and I have the basis of an L88 replica engine (same as ZL-1 minus the alloy block). So it'll have to do (and will be still less than 1/4 of the price of that ZL-1 replica)!

[makka]

thanks for the responses so far guys, but keep em coming, the more info the better

( Ned Loh ) thats precisely why ive started this thread, to get all the info i can before starting to buy anything, i'll be thinking different combo's and once i'm happy with the combo i want i'll start making dents in my wallet (although its already empty lol) oh and i'll be getting the machining done but assembling this all myself.

(myss427) the AFR's we're one of my picks as i have read plenty of good reviews about them, does anyone recommend brodix?, the reason i'm staying with a 350 is because the car i have is engineered with a 350 in it, i havent looked much into the stoker cranks yet but one of my ideas was a 408 stroker, if i setup a cood combo with a 408 i shouldnt have much trouble in succeding in my goal.

****also while on the topic of heads, i know basic knowledge like porting makes good power gain etc but can i get some light shead about some specs like all these degree* and cc's etc ? i'm very willing to learn all aspects of knowing the in's and out's of different kinds and styles of heads and what gives better flow and more power or compression etc****

(yel327) thanks for those links mate, have been looking at the summitracing site and been staring at some of their lunati lightweight cranks, as the shipping is under $400 to my door i'm very much considering getting a few parts through these guys as even with postage its still cheaper than getting them through rocket.


thanks for your help so far guys, lets keep the replys coming and lets get a nice neat little engine together

Stroking to a 408 requires a bit of work, Boring the block so that the cylinders are even closer than they need to be, the 383 itself will be great bang for buck.

The angle you see on Head descriptions are about the spark plug. So in this case a 23 degree head has the spark plug angled 23 degrees towards the exhaust port. The cc's have two measurements. 220cc would be the entire intake volume, where 65 cc is the volume of the combustion chamber. Obviously bigger heads for bigger engines. Brodix make good heads from what i hear as does Patriot. Ideally you want them to flow 300 cfm to make good use of it all.

Don't know much bout Lunati... SCAT are very reputable and very trustworthy. Making complete rotating assembly kits. Like this. http://www.summitrac.../SCA-1-40755BI/

Apparently stay clear of Hypereutectic pistons. May as well get Forged.

If your going to offer advice, make sure its correct first, the degrees on chev heads actually relates to the angle of the valves in relation to the deck surface, it has nothing to do with the spark plugs

[rodomo]

I don't know much about Chevs but I heard form a mate that for best results the plugs should be pointing towards mecca?

[dattoman]

Best to have the plugs not pointing at the pipes

My Chev has straight plug heads when I dismantled it
Now it has angle plug alloys

[dattoman]

Bigger head CC in the chamber lowers your comp ratio
Bigger port CC's means it can flow more air
But if they are too big or your volumetric efficiencey is low then it will bog down at lowe rpm and be a pig down low

So its a compromise if its a streeter

Changing from say 23 to 18 degree heads can make a significant difference.... but them no maifolds etc fit easily and you need specific ones not off the shelf... or custom machining
So stick with 23 deg unless your building a race engine or have a bottomless wallet

[dattoman]

For good off the shelf CNC ported heads I bought the Patroits
https://www.patriot-...7&cat=41&page=1
I "flow tested" about 12 different options on the desktop dyno and the 2 top performers were the Edelbrock Victor Jnr and the Patriot
The Victors had 1 more HP at RPM but lost alittle in low end torque
Sure I could have made more power... but I just wanted a torquey stump puller
I won't be turning it past 5500 anyway

Though if I was going to push it and had my cash again... I can't go past the ARAO 32 valve heads with B series stage 3 port
http://www.araoengin...es.htm#B-Series

[dattoman]

Only those that want to go fast
Everyone knows the performance is in the heads and flow
Happy to spend huge # on the bottom end... then buy off the shelf heads
Or madly port average heads and still spend the same amount of cash

And thats top of the wazza... the ones I want are only 5500

And I know a certain big block owner that might have bought a set if he could have used his original manifolds
But since they would have to be custom he didn't