Question about aluminum heads

[BARRACUDA1968]

I just built a new 109 stroker that I will be pulling due to a head gasket failure. Freak deal and I'm unsure as to what caused it at this point.

Here's my question, why don't more guy's run aluminum heads on these motors? I don't want to debate about flow and HP just the fact that shouldn't aluminum heads help with detonation which is our enemy?

I may have too much compression which is one of our theories on why my motor puffed the head gasket. My target was 9.1. Wouldn't aluminum heads be more forgiving?

Just asking because all my other engine builds in naturally aspirated motors have aluminum heads so I can run a little more compression and save weight.

Opinions please. School me a little.

 

[Nick Micale]

You have actually answered your own question!

The greater heat dissipation of alum will help immensely in reducing detonation, and we almost always up the compression ratio in a performance build because of this factor.

One other consideration with alum heads, all of the 3 brands of 8 bolt heads are more resistant to "lifting" or deformation a lot more than the iron heads. The M&A and TA heads are significantly stronger/stiffer than iron heads.

The TA alum heads are derived from the M&Aa head, but were re-designed to add even more strength, especially in the combustion chamber area.

 

[BARRACUDA1968]

Well it seemed logical to me but I didn't see a lot of guy's running them and wondered why. Me personally, I would take every possible step to keep the motor from detonating. I'm like $11,000 in to this build so what's another few bucks to protect my motor.

Nick if I go aluminum heads can I use my HS rockers and valve springs etc off my Champion irons? Will push rod lengths be different? I just went through my irons so they are fresh. I'm seriously considering this mod since I'm pulling the motor anyway. I can always sell my Champion Irons to offset some of the cost.

 

[bison]

The combustion chambers in the aluminum heads require less timing than similar combos with iron heads. Don't think you can get away with more timing because the heat dissipation is more. Increased CR is important when trying to make power but will narrow the timing window even more. Some don't believe the timing I run when i tell them. More isnt better. The correct timing is.


BPE2013@hotmail.com

 

[BARRACUDA1968]

My motivation here is purely self preservation. If aluminum heads take a little of the edge off detonation then it makes sense to me to have them on one of these motors at the level I'm at. I would definitely get some schooling on the tune aspect like you mentioned as well. I'm not after more power and I'm not trying to reinvent the wheel. I just want a little more head room in the detonation department if that makes sense.

I did a search and read through a couple threads on the pros and cons etc. I know I can go fast with what I have. But could of also went fast and spent a few thousand less than I did on this motor.

My hiccup with the head gasket could just be a fluke deal. Tune was good and zero KR at 18 boost.

Since I'm pulling it I thought why not get some opinions on better heads and take advantage of the benefits of aluminum if there was any. Sounds like there is.

 

[TurboTnZ06]

We have almost the same build. My GN1's I'm glad I went with them. Mine aren't race ported. But do have roller rockers on individual studs. Don't forget you'll want to buy new valve covers and breathers. The only downside is that I run HR engine mounts and A/C so I cannot remove the passenger side valve cover with the engine bolted in the car. At 18 psi you should be running high 10's with a good launch. My best mph at 18 psi boost with a locked converter was 125mph in the 1/4 mile.

 

[BARRACUDA1968]

I have these valve covers. Will these work on the T/A heads? And why won't I bee able to get the passenger side valve cover off in the car? I have HR mounts as well.

 

[Lil Truck]

Those will fit the TA heads perfectly. The reason you cant get the passenger valve cover off is the raised rail on the TA head puts the cover about 1/4 inch away from the AC heat shield. It may work without the heat shield ???

 

[BARRACUDA1968]

I see, thanks for the info. That sounds like a pain if you even need to remove the valve cover.

 

[TurboTnZ06]

I haven't had to pull my valve cover yet since 2010 when I did my engine.

Since you already have a powerlogger and AEM, upgrgade to the 6.1 TT chip and get wideband correction. You're still using a stock type fuel pressure regulator, do you have enough fuel pump?

 

[johnplogii]

In the first post you say your target was 9.1, is this for compression ratio or air/fuel ratio?

 

[BARRACUDA1968]

I haven't had to pull my valve cover yet since 2010 when I did my engine.

Since you already have a powerlogger and AEM, upgrgade to the 6.1 TT chip and get wideband correction. You're still using a stock type fuel pressure regulator, do you have enough fuel pump?

I have a RED's Xp pump, should be enough.

In the first post you say your target was 9.1, is this for compression ratio or air/fuel ratio?

Compression ratio.

 

[dynoman]

Have you looked into coating the combustion chamber & valve faces ? I was going to have it done when I got new heads for my rebuild , but I found a fresh 400 mile old long block & I wasn't going to pull the heads on that motor. Check out Swaintech race coatings , I know that they do John Force's pistons & other motor parts , so there must be something to be had .

 

[BARRACUDA1968]

Have you looked into coating the combustion chamber & valve faces ? I was going to have it done when I got new heads for my rebuild , but I found a fresh 400 mile old long block & I wasn't going to pull the heads on that motor. Check out Swaintech race coatings , I know that they do John Force's pistons & other motor parts , so there must be something to be had .

Never heard of that in a combustion chamber? I have had pistons coated in the past to achieve a piston to wall clearance.

 

[Lil Truck]

I see, thanks for the info. That sounds like a pain if you even need to remove the valve cover.

I have the TA heads and valve covers on my new combo, If I have to remove the pass valve cover I expect I will have to remove the pass motor mount and rotate the engine down? Nick M. probably knows the best way....

I love the TA heads, valve covers and headers everything fits perfect and runs strong!!!

 

[dynoman]

Never heard of that in a combustion chamber? I have had pistons coated in the past to achieve a piston to wall clearance.

Check out their web site , Lots of interesting info. A lot of racers around here use them cause they are local , Rochester NY area. swaintech.com

 

[Lil Truck]

What type of head gasket, fasteners and torque procedure.........re-torqued?

 

[BARRACUDA1968]

I paid to have the motor built so I got it back with the heads on it. I finished the rest. So I can't answer the TQ specs and procedure. My engine builder is real good so I'm not anticipating an issue like that. Now if I had installed them then it would be a STRONG possibility. We used head bolts. Will be using studs this time.

The gasket was a stock type at 60 thousands.

The block was decked twice that I know of. I have both engine build sheets. We cut it 6 thousands. I can't remember how far the piston was in the hole this time but .19 rings a bell? Don't quote me on that.

The heads were cleaned up as well. I'll be CC'ing them when I get them off so I know for sure. They were not CC'd for this build.

The head gaskets that came off the old motor were cometic .100

We decked the block .06 and shortened the head gasket .40 plus cleaning up the heads.

To sum it up I'm not sure what final comp ratio ended up being? With 46cc heads I don't think were should have been too far off the mark (9.1)

I'm not going to re-TQ, just pull it and investigate. I'm 3 hours away from having the motor out so might as well. Much easier on the stand than leaning over the fender. My knees can't take that crap anymore.

I am strongly leaning toward the aluminum heads. I just don't see a down side and yes I have read through many threads about not being worth the money and no real gains. My thought process is if set up right where is the down side? If they will help with detonation and not lift as easy like Nick say's I'm in. If I make a few ponies then wonderful. I should have supporting mods to use them.

 

[Undercover87T]

My new motor pick up 100whp with 4psi less boost and 3 degrees less timing than the old combo. Besides the added cubes and cam, alot of that was in the heads. I was told by my engine builder that they can "seep" if something called seal tabs aren't added to the coolant. Something to do with iron block and aluminum heads. Another side benefit I didn't think of was that aluminum heads take a substantial amount of weight out of the front of the car.

 

[BARRACUDA1968]

From my experience with naturally aspirated engines cylinder heads are where it's at. I have a 340 mopar stroked to a 416 CI. I had a set of edelbrock ported heads on the motor. Flow benched and done right. Car ran 11.10 at 119 with a 1.54 consistent. Had 10's in it.

Indy cylinder head came out with a 360-2 CNC ported head that flowed like a big dog. Made the change and had a custom cam ground for the new set up. Car made 125+ HP at the tire with a bad tune. 545hp and 564 TQ, It had more in it. My buddy in Texas has the same build as me but with W2 heads that don't flow like mine but his car is an A body with same gearing,cam and weight. He runs 10.20's at 130 mph so I got him covered if I had the balls to run the car again but I don't, won't risk it. I couldn't get the car out of the hole but I did go from 119 mph to 130. I almost wrecked the car that day so I've never been back with it. I cheated a bad situation with a car that means a lot to me so I thanked God for the free pass and parked it. That's why I bought the GN, sounded like a fun car to go fast in. Just always scratched my head as to why more guys aren't running aluminum heads on a detonation prone motor.