Winter freshen up. Changes.....

Here's what I have now:

D1VE block, bored .060", 472" CID
balanced rotating assembly
2YABC crank with King bearings
Eagle H-beams
Carl’s custom dual flycut forged Probe pistons (P51 or SCJ) 15cc dish
"cheapskate" A429 heads (391/200cfm and cut to 62cc) Should be 11.4:1 according to my math
3/8 push-rods
.641/.677 SFT custom grind cam from Scott Johnson, 261/274 duration
PRW stainless 1.73 roller rockers and Jomar stud girdles
Motorsport “victor” intake re-drilled for a 1050, not ported at this point
1050 dominator carb, 1" spacer
14 x 4" air cleaner with K/N xtreme top.
MSD dizzy and 6AL
PRW electric water pump
Canton 7qt pan
canton windage tray
Melling HV oil pump and ARP pump shaft.
Custom made front exit headers, 2" primaries with 3.5" collectors.

Now that I have a job where I will be an OT whore all winter and getting some nice pay check's I can play with my heap a little. The engine has 300 passes on it so I would like to freshen it up. Freelander wants a cam/piston swap to get the HP up to his cheapskate build but I'm limited to 100LL AV gas as the fuel that I can afford/get easily ($2.50 a liter here) and I'm nervous of big seat pressures on an old head with 3 repaired stud bosses. I'm not sure what compression ratio I can get away with on that fuel??...I'm thinking of a new custom SFT cam from Blake or Randy, there is power to be had there I'm sure over what I have now. This combo made 563/565 on the dyno with oiling issues and 10L in a 7L pan. Using my ET and weight it shows 600HP on the nose with the oiling issue fixed. New heads are possible but not near the top of my list with the exchange rate right now. What do you fella's think I should do???? and - go....

New AFR heads and intake, new cam, and NOS Big Shot plate!!

LOL I was waiting for the most expensive option to come first...Our dollar sucks as usual or I'd be all over that except for mr frosty...that shits like $12/lb here!

What is the vehicle specifics, how is it to be used 80% of the time and is there an RPM range which you would prefer...?

Offset grind crankshaft or 4.3" crank?

Offset dowel cylinder heads to move the valve centerline away from the cylinder wall. (move heads towards inside of block - need to mill intake side of head too)
I believe Kaase did this when playing with the A429's a long time ago.

Not sure how "opened up" the intake port is on your A429's. May be too big for a 472" build. The exhaust looks like it could use some loving too.
250+ cfm is straight forward for the exhaust on these heads.

Intended useage like RM has asked would be usefull too.

Good Luck!!

Race only is the use. I'm running a 275 drag radial pro so with 3.70 gears I'm hitting the 7000 pill at the stripe in good air. Like to stay there or under as far as the RPM go. The heads are in the 390/200-220cfm range from what I remember Dave telling me. He had them on a flow bench when he did the cheapskate build.

The solid lifter grind you have does sound right for a 7000 rpm 472" - there is some power to be gained by a solid roller cam and more compression or just more cubic inches. Those big port A429's start to shine at larger displacements when the CSA starts to get close to what it should be.


What weight are you at? mph at the stripe?

Sounds like a fun ride already.

Last time we weighed it the car was at 3025lbs with my big arse in the seat. The usual MPH is 132-133, best ever has been 136. If I had different heads I'd go for the roller cam stuff but not with these heads. One has 3 stud bosses welded back on, the other has no repairs.

You could look at a more aggressive solid lifter lobe profile.
Comp has some lobe designs for 0.875 diameter lifters that have a lot of area under the curve.
SQ series of lobes for example.
I am not sure how aggressive the lobe design is on the cam you already have.

Yikes on the welded stud bosses. How did those break? Big spring pressure and no stud girdle?

I bit the bullet and put on shaft rockers on my deal. Glad I did.

Cheers

I bought them with 2 repairs and the 3rd one happened on my watch. I always ran PRW girdles, but I switched to Jomar's last winter. I'll see if I can find my cam card and I'll post some specs.

BigRigTech wrote:Race only is the use. I'm running a 275 drag radial pro so with 3.70 gears I'm hitting the 7000 pill at the stripe in good air. Like to stay there or under as far as the RPM go. The heads are in the 390/200-220cfm range from what I remember Dave telling me. He had them on a flow bench when he did the cheapskate build.

Realistically ... you are going to have to change at least one of those parameters if you go faster.
With the same gear and tire size ... faster means higher RPM.
With more power and going faster yet keeping to the same RPM requires a different gear, tires or converter.

rmcomprandy wrote:

BigRigTech wrote:Race only is the use. I'm running a 275 drag radial pro so with 3.70 gears I'm hitting the 7000 pill at the stripe in good air. Like to stay there or under as far as the RPM go. The heads are in the 390/200-220cfm range from what I remember Dave telling me. He had them on a flow bench when he did the cheapskate build.

Realistically ... you are going to have to change at least one of those parameters if you go faster.
With the same gear and tire size ... faster means higher RPM.
With more power and going faster yet keeping to the same RPM requires a different gear, tires or converter.

Understood, with the repaired head I guess I'm trying to be cautious of drastic changes. I'm thinking a different custom cam might be worth a shot, I don't have the cam card in front of me but I remember getting some comments related to the LSA that there was a little power to be had if I changed that. I figured now would be a good time to change that. Realistically, what is the most compression do you think my combo could handle with the 100AV gas? VP race fuel is not cheap or readily available here so that's why the majority of the super pro racers run av gas. There are some who buy the VP stuff, It's like $4/L and up and you have to special order it.

You have enough head to make a good bit more power and still keep it under 7000 rpm.

I would narrow the separation up more too if it's at 110 or more.

I would have it on a 107 or 108.

Also depending on the header, a little more split could maybe help it some

And a lobe with more area can help too.

I built a 466 for a customer a couple of years ago that was almost a twin to your deal.

Heads flowed 380 / 250 and the cam was a 265 276 on a 106 solid roller with .785 int lift and.779 exh lift.

1050 4500 with a ported Victor.

751 hp @ 6400 rpm and 690 ft lb tq @ 4400 rpm.

Very heavy mud truck 5000 lb.

Just some documented fodder to chew on.

IDT-572 wrote:You have enough head to make a good bit more power and still keep it under 7000 rpm.

I would narrow the separation up more too if it's at 110 or more.

I would have it on a 107 or 108.

Also depending on the header, a little more split could maybe help it some

And a lobe with more area can help too.

I agree ... somewhat.
It is immaterial WHERE you make that additional power because, (once again), if you want to go faster you need to make the decision to spin it higher or put less gear in it.
Only after you figure your priority and which avenue you prefer can anybody give you any informed recommendation ... until then.

IDT-572 wrote:I built a 466 for a customer a couple of years ago that was almost a twin to your deal.

Heads flowed 380 / 250 and the cam was a 265 276 on a 106 solid roller with .785 int lift and.779 exh lift.

1050 4500 with a ported Victor.

751 hp @ 6400 rpm and 690 ft lb tq @ 4400 rpm.

Very heavy mud truck 5000 lb.

Just some documented fodder to chew on.

If I had a new cam ground it would be a SFT deal as it is now. I don't trust my repaired head to handle the heavier roller cam seat pressures. I think the LSA is a 110. I have to dig out the cam card.

Randy, a gear change is not an issue if needed. I still have the stock C6 first gear so I could have the 4R100 first gear put in the tranny to help it out of the hole if needed. I started from day one with 4.11's, to dump some finish line rpm I went to 3.89's on a 28 x 10.5 slick, did the same thing again with the 275 drag radials and put in the 3.70's that are in it now.

BigRigTech wrote:

Randy, a gear change is not an issue if needed. I still have the stock C6 first gear so I could have the 4R100 first gear put in the tranny to help it out of the hole if needed. I started from day one with 4.11's, to dump some finish line rpm I went to 3.89's on a 28 x 10.5 slick, did the same thing again with the 275 drag radials and put in the 3.70's that are in it now.

OK ... if keeping the RPM about the same is most important then a camshaft change with more lift and being more aggressive would probably be best suited for what you wish to accomplish. Along with an appropriate valve job to compliment the cam.

With that 100LL gas in a strictly drag race application where the engine temperature is below 140 degrees a compression ratio of near 12/1 would help.

The unported intake might be somewhere to start.

Jess

Here are the cam specs that I have now.