Technical Chevy 327 tuning help

Those castings on his engine are 76ccs , which will Be around 9.2:1 with .016" gaskets and flat top pistons with valve reliefs ( stock pistons) . If you add some cam, dynamic C.R. will be below 9:1. That's pitiful even for over here. 291 casting would be great; I am using them on my coupe at about 10.2:1 C.R.

 

Joel, yes he does have 76ccs... that is why I thought it would be better to find some 64cc or maybe even smaller heads.

 

The market is flooded with crappy cheap heads. I was steered away from the Flo Tek heads that Speedway carries by my engine builder, although they do carry some WISSOTA Dart iron heads that are a good deal. There are a bunch of good aluminum heads at a good price from Dart (SHP line), World and Edelbrock. The 3 x 2 adapter is terrible... just not even close to something that will flow well.

 

Do you know of any heads for sale??

 

This is the steel Dart head I mentioned. A stock car claimer head but on the lines of the small SBC fueli head.
https://www.speedwaymotors.com/Dart...ck-Chevy-Super-Stock-Head-Complete,34612.html

This gets you a good pair of iron heads from World. Supposedly built to order, but still a good pair of complete heads.
https://www.speedwaymotors.com/Worl...ock-Chevy-Iron-Heads-Straight-Plug,11159.html

 

The USA uses the AKI (anti-knock index) for octane ratings. I believe most (possibly all) of Europe uses the RON (Research Octane Number).

95 RON is approximately equavilent to 91 AKI

We have 93 AKI available at our local stations, which is approximately equivalent to 98 RON.

Oh, and for those unfamiliar with the term AKI, it is (RON + MON) / 2.

Jon.

 

Absolutely not, I don't know where you got that info from. Here's a simple build to review on a few parts.
http://www.superchevy.com/how-to/en...-school-small-blocks-one-blown-and-tri-power/

 

Jan 2002 Hot Rod magazine dyno test of several intakes on the same engine, here's the particulars.


The Set-Ups:
*Holley Pro Dominator tunnel ram w/2 750 dominators: 485HP@6200/438TQ@5200

* "The Summit Combo" Wieand Hi tunnel ram and 2 Holley 450cfm: 491HP@6200/443TQ@5500

*Eddie cross ram intake and 2 Holley 450cfm carbs: 480HO@6300/425TQ@5000

*Eddie street tunnel ram w/2 650cfm race Demon carbs: 503HP@6100/452TQ@5600

*Eddie C-26 dual quad intake w/2 eddie performer 500CFm carbs: 446HP@6200/405TQ@4800

*Eddie C-357 B 3 duce intake w/3 Rochester 220cfm carbs: this one gave them problems and they cheange the cam to a [email protected] for better vacum signal but they couldn't run it on the dyno becasue it was running to lean and didn't want to trash the motor .they said that on a trunacted test between 3K and 5300 the set up made between 8 and 12 HP and TQ less than a 625 road Demon on a RPm air gap intake. which they felt was very impressive.

* Offy 6 pot intake w/ 6 Stromberg 97 2 barrels: 350HP@5900/366TQ@4300

 

I have a few sets that need to be rebuilt, and here is set set of already rebuilt ones for sale. But I ´m sure you can find them locally and maybe for less in your area. At 950 Euros you could also buy a new set of better performing aluminium heads from summit.
https://www.ebay-kleinanzeigen.de/s...-zylinderkoepfe-camel-hump/880290423-223-1033

 

Well after a bit of searching around and following a bit of advice, I’ve managed to find a pair of good corvette heads.
A pair of 2.02/1.6 valve 461 and 462.
Both came off a running driving car and only changed out for a set of ally heads.

 

Cool
If you get them; do yourself a favor and have the valve stem to guide clearance checked, regardless of what you are told by the seller, something as simple as a quick, hand check if accurate measuring tools aren't available, they will require disassembly, better now than after the engine is built.
I did the very same thing as your seller, I had purchased a pair of "rebuilt" heads for my new 350 to find out shortly after engine break-in that the plugs were fouled due to wobbly valve stems, ended up replacing them with the newly released Edelbrock aluminum heads.

 

Ok many thanks

 

Denny, I totally agree. I have a 327 in my Merc, snobbery would say it should be a big block. People think it's a 350 when I tell them it's a 327 they light up a little.

 

DDDenny is correct about the guides. Most can be fixed with " guide liners". These are sleeves that are pressed in a worn guide after enlarging the hole. I also use Teflon seals instead of stock. I also put screw in studs on all my heads. With the L79 cam, 1.6 rocker arms will give more lift and not much more duration. Good score on the heads.

 

This is what I’ve bought. Hopefully haven’t bought a pair of lemons.
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/123309549855

 

I think your good with this purchase; it has the studs and guide plates and probably the better valve seals. Id still check the valve guides for wear and the valve springs for correct seat pressure for your cam.

 

Going to change the cam as well and correct springs come in the kit.
I’ll check the heads over before they’re fitted.

 

There is "fast" and then there is "stupid fast"......
200+hp in 2000lb car will probably be fast.
If it was me, I would drop the lump in as is and drive it...if it doesn't scare you pull it out and build it up.
But that's just me...
Chappy

 

I’m not going for a high output motor but I want something a bit more powerful and reliable.
I’ve been told the motor is a good runner but it’s unknown to me, and I don’t want to build the whole car up to find out it’s a piece of shite.

 

I have run aluminum heads on my 355 street motor for 20 years this year (or 21 I don't remember if I screwed it together in '97 or '98). I like 'em real well.

I am a mechanic and not a technician, so take what I am going to say with a grain of salt. There are two reasons to bore a motor, one is that it is too worn to go back together stock and the other is to hit a specific cubic inch displacement. That goes for street or race.

As for camshaft I like the L-79 cam shaft for an everyday SBC. Mild lope and good flat torque curve. If you want to go with a solid lifter motor and want it to sound good and still have good manners try a Duntov 30/30. Actually both cams had Zora's fingerprints on them to some extent. Both are GM designed cams for a GM motor and they both work real well.

The rest is up to you I suppose. Good luck with the build.

 

Thanks for the input. All suggestions and comments are appreciated

 

Make sure to get pushrods specifically hardened for guideplates.

 

Yup Molly pushrods or Manly composite guide plates. I ran the Manly plates for a while (about 30K or 48K in the UK) and they held up really well.