460 Ford build

[prairiehotrodder]

As a way of helping anyone who may be doing a similar buildup (460 block with the new AFR heads #3805) My motor needs 8.680 intake pushrods and 9.050 exhaust pushrods. Check your own to be sure.

[In-Tech]

Started building this engine finally. With the mahle flat top pistons (not cut for the AFR valve pockets) and the AFR heads and this cam http://www.lunatipower.com/Product.aspx?id=2317&gid=284

and a comp 3 way adjustable timing set, and no head gasket, the intake valve has about .002 PTV clearance. When the chain is set up on the zero setting. With it on the 4* retarded setting it has about 1/8". These numbers will increase with a head gasket.
Brian

Are you sure? I usually see ~.009" per degree(crank) Yes, head gasket thickness adds more than the thickness of the gasket on canted valve engines.

[prairiehotrodder]

Well i'm sure your measurements will be more accurate than mine. This is my first serious 460 build and first time with these heads. Just in the mock up stages. I will be notching my pistons for more clearance. Just ordered the Lindy notcher tool today for the 2.25" intake valve. I know the owner of this motor will drive it hard and probably not maintain it as well as i would like. Need lots of PTV clearance. It could stand to lose a little compression as well. I'm in the 11.25 CR range if my math is correct. It started as a mild street / strip motor with stock iron heads and has morphed into much more serious than i had originally planned.

[Old School]

The cam card shows the cam is ground on 110 and the intake lobe in the engine at 104. With as large an engine you have and too much compression I would degree the intake to 107-108. Closing the intake later will not hurt a 460 inch engine, lower the dynamic compression a little and have better mid range and top end power. You will not need the low end torque of the 104 closing point.

[prairiehotrodder]

thanks old school, I'm gonna check the cam right away. See where its at and likely take your advice.

[prairiehotrodder]

could use some help here. I'm not awesome at degreeing cams but i can get repeatable results. Its just deciphering them that confuses me. My timing chain has only 3 adjustments. 0 , +4 and -4 . I'm set at zero. My cam card says it wants Int open at 18 and close at 46 @ .050 . I've checked it over and over am getting 10 and 54. Does this sound right? If i was wanting to follow the cam card i would advance it 4 degrees right? And if i want to follow Old schools advice above ^^^ Then just leave it where it is?
Brian

I think i measured ICL of 108 if i'm doing it right. Just bring it to full lobe lift?

[prairiehotrodder]

but if i measure the ICL by finding .050 on either side of full lift then dividing the middle as the cam card says is the right way to do it. I end up with an ICL of 111.5 . So the more i think about this, The cam is about 8 degrees retarded from where the cam card wants it to be. I should probably set the chain at the + 4 position and re-measure. Theoretically that should put me at a ICL of 107 .5 and IVO of 14 and a IVC of 50 ? Am i thinking this through right? And i'd need to advance it 8 degrees to go to exactly what the card wants?

[prairiehotrodder]

Sorry for all this posting. Hopefully it can help someone besides me. I was right the first time i posted the IVO and IVC. Advancing the cam 4* to the +4 position on the timing chain took me to the exact specs on the cam card. I'm gonna run it at the 0 position which should make the cam 2 degrees advanced instead of 6 on the card. That should give me more top end, more PTV clearance (maybe) and a little less dynamic compression as was mentioned a couple posts back. The car is a 87 mustang with a small drag radial so a little more top end and a little less bottom end should be a good trade off.

[Old School]

If you use the +4 it will advance the cam 8 degrees as you found out. I think the cam may be retarded as the 111.5 intake centerline shows 1.5 retarted. The best way to fine tune the advance/retard is with bushings in the cam gear. Its not hard to do, a 2/3 degree bushing will put you on 109/110. The thin side of the bushing goes at 6 o'clock. I would rather have the intake center line on 108/9 than 111.5.

You will have to drill the cam gear to 13/32 for the bushings. The instructions will also tell you to drill the 3 bolt holes. I would not drill the bolt holes with the 13/32 but only drill them enough for the gear to center and the bolts go in freely. If you drill the holes too big the dowel will take the most of the stress instead of the bolts.

All this is moot if you do not want to use a bushing. The 9 way timing sets will provide 2 degree increments for advance/retard.

[cgarb]

Maybe I am not remembering correctly but doesn't a BBF have a single bolt in the center of the cam holding the gear on? Drilling clearance for the 3 bolts is a Chevrolet thing...

[prairiehotrodder]

Yes its a single bolt with the fuel pump eccentric bolted to the nose of the cam. As far as the cam position goes i just put it where the cam card called for it in the end. My chain didn't have the adjustment to get it where was suggested above. I bought the cheaper chain back when this was a cheaper motor. I appreciate the advice given but in this case i didn't end up following it. If the engine doesn't perform up to expectations (i'm sure it will) at least i will know the cam is in where Lunati wanted it to be. I can make changes from there if the customer wants.
Brian

[Old School]

Maybe I am not remembering correctly but doesn't a BBF have a single bolt in the center of the cam holding the gear on? Drilling clearance for the 3 bolts is a Chevrolet thing...

You are correct. It's easy to tell a Chevy mechanic.

[prairiehotrodder]

Here 's a picture showing where the AFR head intake valve goes as compared to the factory style valve relief. With the cam positioned where the cam card called for, a head gasket installed, and the head just snugged down lightly (not torqued) I had basically zero PTV clearance. Now i have tons. I still will polish up these notches for a smoother finish. Set my depth at 3/16
Brian

Picture 240.jpg

Picture 239.jpg

[RevTheory]

Wow! Well, at least they were close, lol

[Lem Evans]

Like Kaase did with the SCJ & P51 head....the AFR guys did a good job of getting the intake valve off the cylinder wall.