New IDT A Plus Cylinder Heads

Our A Plus cylinder head uses all current "A" type hardware, TFS intake manifolds, valve locations (check piston fly cut diameter) and rocker arms. The A Plus heads are completely CNCed (chambers and ports) with valve seat machining. The heads are set up for a 2.500" intake valve and 1.820" exhaust valve. These heads have peak intake flow at 516 cfm and flow over 500 cfm at 0.850" lift. The exhaust flow peaks at 352 cfm and flow 338 at 0.850" lift. The have ductile iron seats and bronze alloy guides for a 11/32 valve. The guides have been set up for 0.3415" diameter stems. The current chamber volume is 98.5 cc's but can be milled to 76 cc's. Heads are ready for shipment - $3,375 per set. Also included is a set of out intake gaskets. If you have any questions, please call at 810.395.2779 or email at jay@idtracingheads.com.

Jay
Those are some great numbers. What are the .500 lift flow figures?
Sounds like you have a nice setup.
Thanks,
Keith

Intake
@0.550 = 405
@0.650 = 461
@0.750 = 488
@0.850 = 503

Exhaust
@0.550 = 273
@0.650 = 301
@0.750 = 323
@0.850 = 337

No pipe was used on the exhaust port, only a radius exit.

Maybe I should keep these in mind for my 600" 4.60 x 4.5" 11:1 pump gas deal I'm working on. I'm thinking a cam of about 280/288 at .050 and .800 lift on a 112/114 lobe sep. looking for power to 6,800 - 7,000. Is the 2.50 valve to big for the 4.60" bore?

Maybe you have something better suited?

Jon

They sound like a great piece.

The 4.600" bore would be ok. An engine that Chris Holbrook built that made some big hp had a set of the A Plus heads with a 4.600" bore. I wouldn't want to use anything smaller than a 4.600" bore. Quickly calculating:
4.600" bore
4.500" stroke
10.310" deck hgt
0.010" piston below the deck
flat top piston with 6 cc of valve relief
4.660" bore gasket with a 0.051" compressed thickness
6.800" rod
1.250" piston CD
99 cc chamber
would yield around 11.05:1 CR
(did not account for crevice volume - piston top ring volume)

Barney wrote:They sound like a great piece.

They definetely are, i just recently purchased a set of these from jay to put on a 618 and i am very impressed with the work that went into these heads and jays service is top notch also!

IDTJay wrote:The 4.600" bore would be ok. An engine that Chris Holbrook built that made some big hp had a set of the A Plus heads with a 4.600" bore. I wouldn't want to use anything smaller than a 4.600" bore. Quickly calculating:
4.600" bore
4.500" stroke
10.310" deck hgt
0.010" piston below the deck
flat top piston with 6 cc of valve relief
4.660" bore gasket with a 0.051" compressed thickness
6.800" rod
1.250" piston CD
99 cc chamber
would yield around 11.05:1 CR
(did not account for crevice volume - piston top ring volume)

thanks for the information.

Any benefit in running a smaller chamber and more dish in the pistons?

I was thinking .005" in the whole or zero deck.

G

Does IDT have a web page?

Jon

Great price for something that flows like that!

Would stainless valves be suitable for any builds? What kind of build? Are these titanium only heads?

I would recommend a titanium for intake intake valve because of the mass (2.500 diameter). The exhaust can use stainless steel (1.820).

I saw these in person @ Lee's Shop ...they are purtty

When are you getting a set of these heads Nick? Let's face it, you need something like this to keep up with the bluebird of happiness. That and an adult size set of rear tires.

bruno wrote:I saw these in person @ Lee's Shop ...they are purtty

you saw them bolted on,if you'd had a look at the valves.........