cool head

[250ex2003]

Who is running the cool head with changeable domes? What are the advantages over milling a stock head? Whats the best size dome to run for premium pump gas with stock rods?

[bloodmoney23]

Never had one but wanted one, not to sure exactly on most of your questions but its better than just milling the stock head due to the fact changing dome size is going to cause it to run warmer and the cool head runs more coolant through it than the stock keeping it cooler. other than keeping it cooler, milling your stock or buying the cool heads head there really is no difference. maybe small small power gains if that.

[250ex2003]

Thanks for the reply. Sorry if I was hard to understand. I meant what cc on the cool head (18,20,21) can you run and still use pump gas. At some point you would have to go with race gas. I was also concerned about the compression ratio being hard on the rod strength. Anyone running the cool head notice any perfpormance gains? Again, thanks for the reply.

[bloodmoney23]

well im not sure what cc dome it takes to run race fuel rajuncajun might be able to answer that. he has the domes and i believe still run pump. The rods can handle a much higher compression unless they are seriously abused. You would prolly throw a bearing long before a rod but that would still take a long time.

[RagunCajun]

around 150psi you need to start mixing gas fuel or av gas i think. The main goal is to avoid detonation.

I run a NOSS head(best head imo because you dont have to change the studds) with 20cc domes. I run 94 octane pump gas. Runs fine but i know a lot of places only can get 91.

I dont know enough to tell you what you can run safely. I only know 21 is the safe point for the majority. 22 is stock.

I would run 18 but i dont want to mess with anything like race fuel. pain in the arse.

Just be very careful and patient when putting it on. It's very easy to pinch an o-ring and there's a ton of them. I did that once and it ran like **** once shee heated up. Simple mistake on my part though.:rolleyes:

[Hondamaster5505]

I heard cool heads are notorious for leaking. Supposedly the NOSS heads dont and are better with the removable domes.

My father just has his head shaved and compression is around 135psi

[RagunCajun]

cool heads leak due to user error, not the product.

[machwon]

There is not much difference at all in the performance of a properly done stock head vs a cool head, especially for pump gas. You can safely run 21cc's on pump gas. I do a stock head mod for race fuel and it only gave up 1 hp to the 19cc domes. Not worth the extra $$ in my mind.

[250ex2003]

Thanks for the reply Bob. On the 19cc what octane would you need? I can get cam2 at some gas stations (104 octane) What hp gains can I get from stock to say 19cc or a stock mod to race gas?Thanks again

[bloodmoney23]

Originally posted by 250ex2003
Thanks for the reply Bob. On the 19cc what octane would you need? I can get cam2 at some gas stations (104 octane) What hp gains can I get from stock to say 19cc or a stock mod to race gas?Thanks again

1.5-2hp gain im guessin. do a port job instead.

[Hondamaster5505]

Originally posted by bloodmoney23
do a port job instead.


x2222

[Hondamaster5505]

my dad can mill heads, but you'll get a bigger gain by porting. How much comp. you runnin? His w/ the shaved heads runs about 135psi per cylinder..

[Washburn]

I have the Noss Head with 20cc domes +4 timing advance and all of the other boltons 2:1 trinity intake with 35PWK VF3s 1800ft above sea level

Im running 160 each cyl and 93 is fine with it. thats the limit though as soon as I bump my timing to +7 and get some 18cc domes its VP110 Straight.

The Noss Head cools alot better than a cut stock head. Looks alot cooler too but I stick with performance

[RagunCajun]

it's not about peak hp if u go from 21 to 18cc domes, it's the added low end grunt up you get.

A cool head is a great idea just like milling the stock head. I'd prefer the coolhead because i like low engine temps. A port job is the best bang for the buck.

Remember everything needs to work together.