Indy heads versus X Heads

[pettybludart]

Can anybody tell me the diff. Mine are 69Xheads ported and polished 202,160 valves comp b-hive #26986-16,retainers comp#795-16 keepers comp#626-16,M.A.V.Jbowl hogg regrind for std.valves and bronze liners.I just want to know how much better the indy heads would be.Is there any comparison???

 

[3404spdvaliant]

Well, first port volume, and second airflow, third light weight, and finally forth better rocker geometry.
But consider the velocity difference [throttle response], yours have more flow velocity than the indys which is probably better for what you are doing lots of street driving[not to assume too much]. Then there's thermal conductivity.....

 

[70aarcuda]

FLOW #’s
INDY 360-1 Hand-Ported

LIFT--------AS-CAST-------PORTED
.100”-----72.5/51.8---------82.8/N/A
.200”-----138.0/90.4-------157.3/110/4
.300”-----198.0/132.2------217.4/158.0
.400”-----239.8/162.9------262.9/203.6
.450”-----255.6/170.8------286.0/214.6
.500”-----270.8/177.0------304.0/221.9
.550”-----278.4/182.9------318.1/227.1
.600”-----277.7/185.6------322.4/230.5
.650”-----271.2/187.3------332.9/237.4
.700”-----270.8/189.8------334.0/241.1

this is what Indy flow,,,,,what does your x heads flow...

from www.shadydellspeedshop.com

 

[moper]

All we can tell from what you post is they are iron. You need to get some flow numbers and volumes from your specific heads. I dont think iron in most forms can compete with the Indys on an engine designed to make use of them.

 

[Baxter61]

I dont think iron in most forms can compete with the Indys on an engine designed to make use of them.

What kind of motors do you think can make use of them? Whats your general opinion of them? I was considering getting a set.

 

[3404spdvaliant]

I dont think iron in most forms can compete with the Indys on an engine designed to make use of them.

As would an engine designed for lower port volume iron heads.
As would anything mix matched as opposed to matched for that matter.:munky2::toothy10:

 

[moper]

340, you're right. And the technology for iron heads was perfected in the 70s and the parts that best match are heavy heavy in comparison, domed hurting flame propogation, and simply don't make use of a lot of knowledge gained since then. I'm sure you already know that tho .

As far as what kind of engine I might spec them for... I dont think anything with a factory stroke and going in a street car and has a realistic budget really needs them. $3500 plus special headers I think is a little much for a top end. They have more room to grow than RPMs, but RPMs with a good CNC job are a tad less coin, use standard headers, and will out flow more than as-cast oval -1s with only a slightly larger port volume. Also, I don't like the 2.10 intakes. IMO they are just too large for every bore size in std blocks and are even shrouded when the bores are notched. With a 4" or longer stroke engine, they offer a great package with growth room RPMs simply can't.