Home ported sbc 441 heads

[6.50camaro]

Intake
Lift Open Close Duration
.006 37* btdc 75* abdc 292*
.050 12* btdc 44* abdc 236*
.200 29* atdc 3* abdc 154*
Exhaust
.006 82* bbdc 31* atdc 293*
.050 56.5* bbdc 1.5* atdc 238*
.200 16* bbdc 39*btdc 157*
this gives a 106* intake centerline a 117.5 exhaust centerline and a 111.5 LSA with 68* of overlap.
The cam is supposed to be 234/238 @.050 112 LSA and told to install at 107* intake centerline
106* intake centerline was as close I could get with the bushings I had, it was that or 109* I chose a little more advance.
I know I check max lobe lift but it appears I forgot to write that down, so it must have been +or- .001. lift at valve with 1.5 rocker is in .539 ex .548 .

[steve cowan]

Dan,
How hard to move cam around?
Maybe backing it up 2 - 3 degrees will put IVC in a better place for your rpm window.

[6.50camaro]

Dan,
How hard to move cam around?
Maybe backing it up 2 - 3 degrees will put IVC in a better place for your rpm window.

Not impossible, but not that easy. It would be almost just as easy to pull the motor.

[1980RS]

It's great to see a lo-po head that GM made and watch someone make them work well. Good job.

[vortecpro]

It's great to see a lo-po head that GM made and watch someone make them work well. Good job.

When it comes to production SBC heads, the 441 casting is the best most workable casting I've seen, Theres a reason its so popular in NHRA Stock and Super Stock. In fact there's a NHRA stock 69 Camaro Rochester 2BBL 350 441 headed car that's been 10.90s, I believe its a L/SA. The Sorenson brothers. It also running the Q Jet in F/SA has been at least 10.50s, maybe quicker.

[6.50camaro]

It's great to see a lo-po head that GM made and watch someone make them work well. Good job.

When it comes to production SBC heads, the 441 casting is the best most workable casting I've seen, Theres a reason its so popular in NHRA Stock and Super Stock. In fact there's a NHRA stock 69 Camaro Rochester 2BBL 350 441 headed car that's been 10.90s, I believe its a L/SA. The Sorenson brothers. It also running the Q Jet in F/SA has been at least 10.50s, maybe quicker.

Mark, your praise for the heads is what led my down this path. They had been sitting on the shelf for years. I just could not make myself come to the point of getting rid of them. Moved them with all my car stuff from NY to Louisiana to Kentucky. I final decided to see what could be done with them now that I have 2 other motors and almost enough parts for a third [need a 4.125 bore block] to play with all the Go Faster after market heads. I don't "race" but a couple times a year. but still enjoy going to TnT's to try my ideas every chance I can. Dan

PS If it was 40 yrs ago I'd be building the car as a 2 barrel for 350/250hp for SS/MA

[6.50camaro]

This is great with old smog heads which look great btw on a what sounds like a very street friendly engine (i thought you had a 243/251 voodoo in it)

You definitely have a 6.90’s in it! 4.88 gear is steep. But what size tire are you running and what does the car weigh ? I feel your 60ft times could also be better. What trans and converter ?

After thinking on your statement about the 60' . I think you are on to something. The suspension is still set for my 422 6.50 index motor. I could try loosening it up a couple clicks on the front shocks to get more weight transfer and more separation in the rear and there is tire pressure to play with.

[SpeierRacingHeads]

327/275HP

[Monza355]

This is great with old smog heads which look great btw on a what sounds like a very street friendly engine (i thought you had a 243/251 voodoo in it)

You definitely have a 6.90’s in it! 4.88 gear is steep. But what size tire are you running and what does the car weigh ? I feel your 60ft times could also be better. What trans and converter ?

After thinking on your statement about the 60' . I think you are on to something. The suspension is still set for my 422 6.50 index motor. I could try loosening it up a couple clicks on the front shocks to get more weight transfer and more separation in the rear and there is tire pressure to play with.

That’s an easy testing as long as the shocks are externally adjustable. But using the 8” converter might hit harder at the line making the current set up work better! I would say as long as the 60ft gets into the high 1.4 range you will get the 6.9x ticket.
How much tire pressure are you normally running ?

[6.50camaro]

Monza the shocks are externally adjustable. last week went to the line at 13.5 psi in the slicks

[steve cowan]

Dan,
What are you thinking about to combat the lifter collapse/ or valve float issues, less rocker ratio ??

[6.50camaro]

Steve, I could do 1.5 all around or 1.6 all around or a split 1.6 int-1.5 ex. I just don't remember this issue when I ran this cam back in 2012-2013 in a 350 with the current 1.65 /1.6 split. Although that was with I feel much better Crane roller lifters and different springs. I had this came in a 350 and it turned 6500 with no complaints. I can't remember if I run10w40 or 20w50 in that it sure wasn't 5w30. Right now i got so many Ideas whirling round my head. but it will be till next season before I can see any track time. Oh if I only did not have those tranny problems back in August when I first got this engine and tranny in the car.

[Monza355]

What lifters are you running exactly and how much preload ?

[6.50camaro]

What lifters are you running exactly and how much preload ?

Howard Max Effort 91160 Competition Products catalog states - 130 to 180 seat pressure 385 open pressure up to 7000rpm.
Install and lashed as per instruction with lifters.

[F-BIRD'88]

What lifters are you running exactly and how much preload ?

Howard Max Effort 91160 Competition Products catalog states - 130 to 180 seat pressure 385 open pressure up to 7000rpm.
Install and lashed as per instruction with lifters.

What is the actual seat and open spring force?

Excessive spring force (with those lifters ) (assuming all are on spec leakdown) may be causing lifter collapse at high rpm. May find benefit in adjusting spring force and verifying lifter bleed down rate on each.