Roller Cam and Heads

[kennygunit 10]

Hello,

 

I am in the middle of a 96 351w build (there is a thread posted here of my build), and I need some suggestions on which cam and heads to get. I want to get fully assembled heads, as well as a cam thats good enough for autocross and open track events. I also don't want to spend over $2,000 for both.

 

The rest of the engine is stock. Stock bore, crank, roller lifters. Only thing thats been changed is cast flat top pistons.

 

Let me know if you have any suggestions!

 

P.S. I am also looking for an intake a carb if you want to throw in some suggestions on that too!

[BuckeyeDemon 211]

if your goal is 550 to 600 hp, then save your money for when you're ready to build the motor for power and just finish rebuilding your stock heads.

[Angel 24]

I agree. Heads that will make that much power will run you close to $2k. You can get some good heads and cam with that amount, but it wont meet your ultimate goal. I waited 6 years to be in a position to build an engine the way I want. Trust me dude. Just wait. You'll thank yourself later.

[1969 Mach1 14]

Kenny,

 

I have been following your other thread. It seems like the build parameters are changind midway through. I agree with the others. Stay the course you started with and save for a later build if you still want to go another route. Changing now can be a slippery slope. I know those stock heads are not the best. If it were mine, and for a street driver and not autocross or open track use, I would consider these options: 1) Purchase a set from Powerheads using yours as a core. 2) Find a used pair of GT-40 heads (make sure they have the larger head bolt holes for a 351w). 3) Find a used pair of C90E or DO0E castings for a 351w. 4) Finish rebuilding your stock heads. If you use your current heads and have time I would consider installing larger GT-40 valves and new exhaust seats in them. Whichever route, remember to get the correct springs for the camshaft you select.

 

As far as camshafts, for off the shelf stuff give Comp cams a call for their suggestion. Morning hours seem to be the best time to call them. They seem to have the largest selection for 351w's. Comp cams also has an online selection tool that you can use before you call. That will narrow the options down some. I run Comp's 284 Magnum Hydraulic Roller that Comp ground with standard (not retrofit) sized lobe base circles. I purchased it directly from Comp, it was an easy smooth transaction and delivery was fast for a cam they had to grind. Personally, I don't prefer Comps Xtreme series of cams only because the lobes are more aggressive and harder on valvetrain.

 

I know most people don't like Ford Racing's camshafts but I have ran their X303 in a carbureted 351w. Slightly mild for a 351w but it ran great for a street driver. I never used their Z303 but may be a little too much for a street driver. I have called Ford Racing tech a few times about this and it seems the older techs would recommend the X303 and the younger techs would recommend the Z303 for a 351w.

 

Good Luck

Edited November 28, 2011 by 1969 Mach1

[kennygunit 10]

Only reason i am considering new heads is i found a problem with one of the threads on the intake side of one of them. I have to drill out the bolt, and heal-a-coil it. I'm going to keep working on it for the next week, but its getting to the point where i might not have the heads done in time with the rest of the engine!

 

As of now though, i am sticking with the stocks. Just thinking of a backup plan :thumbup:

[1969 Mach1 14]

Kenny,

 

The broken bolt is very common on these heads. My 1995 F150 has a 5.8L (351w) and had the same broken bolt problem. I was lucky and able to drill it out without ruining the original threads. I managed to do this with the head on and the motor and in the truck. Heli-coils work great, I have used them many times. Put some red loc-tite on the external thread of the heli coil to help hold it in place. I don't know how true, but I have heard a heli-coil repaired thread is stronger than the original.

 

Good Luck

[kennygunit 10]

Sadly, it doesn't look like i'm going to be able to use my stock heads. The teacher and I spent all class trying to get the bolt out, only to find out during the drilling process, the we won't be able to get it out.

 

 

So, now i'm back into looking for new heads and cam. I talked to the guys at summit racing, and they suggested this setup:

 

http://www.summitracing.com/parts/AFR-1428/

 

and

 

http://www.summitracing.com/parts/TFS-51402000/

 

 

Would i be better off with 58cc or 72cc for the combustion chamber volume? I have flat top pistons

Edited December 1, 2011 by kennygunit

[1969 Mach1 14]

kenny,

 

If you would rather get new heads, thats fine, I can understand. If you want to try more on the bolt here are a couple of methods I have done. This first method involves heat and parafin wax (any candle). The bolt needs to be drilled through completely for the whatever bolt extractor you are using. Heat the bolt until it just starts changing to a red color then quickly hit it with parafin wax, install your extractor and try to remove it. It usually takes two people to go fast enough. The wax melts (hopefully into the threads) and doesn't flash off like most lubricants. I have used this method to remove alot of rusted pipe plugs, rusted hose fittings, and some rusted bolts. The second method is just drill the bolt completely out then chase the threads to clean them up or install a heli coil.

 

As far as what Summit suggested, 72cc combustion chamber seems very large for a small block Ford, that may be a misprint. I would also talk to some cam manufacturers like Comp and Crane for their suggestions on camshafts before making any selection.

Edited December 1, 2011 by 1969 Mach1

[kennygunit 10]

Thanks for the advice Mach 1, but i've gotten to the point with my heads where i won't be able to fix it. I've already lost some head material trying to drill out the bolt!

 

Would the 58cc version be better for me?

 

I have flat top pistons, took off .016" from decking and .009" from the heads (.025" total)

 

Stock compression ratio with dish pistons was 8.8:1

Edited December 2, 2011 by kennygunit

[BuckeyeDemon 211]

what's the compression height of your pistons?

 

i'm surprised your class didn't provide you with the concepts of calculating compression ratio.

[69fstback 10]

heres what i would do.... buy the gt40x alummnum heads.. i can get em for $700 assembled for the pair.... and buy a regular hydro cam kit for around $200... it will still move plenty... with a performer rpm intake and 650-700holley..

 

thats under $1000 for heads and cam... then when its time to upgrade use the other $1000 and sell the gt40x heads for around $500 and youll be golden...

to build a stroker 393/408... so save the $1000 in a account for a later engien build and still have a stout motor with decent heads for only $1000

Edited December 2, 2011 by 69fstback

[1969 Mach1 14]

Kenny,

 

It is a good idea to calculate the static compression ratio to help determine what combustion chamber size to select. If your instructor didn't cover this topic Summit racing has an interactive calculator in their expert advise section. Check it out and you will see the info you need to use it. Do you know what you want for the static compression ratio? I am no expert in that but alot of people safely run 10.0:1 with aluminum heads and premium pump gas. Why did you remove so much material from the deck? Something doesn't sound right there. Was the block set up correctly on the machine?

 

AFR's are good heads. I would have used them if I could afford them. Check with the AFR themself, the 72cc size doesn't sound right. Combustion chamber sizes for SBF heads usually range from 58cc to 64cc. I don't know for sure but that cam may be just a little small for those heads and a 351w. Probably more suitable in a 302, that's a tough call. Plus I don't want to influence you as to what camshaft to purchase. Maybe there is someone on this forum that has used that cam in a 351w.

Edited December 2, 2011 by 1969 Mach1

[MikeStang 247]

Thats not a Bad lil cam for a stocker type 351.....Try the XE Grind cams, they work good with lower compressions.

We ran an XE 274 in my friends 408 with Cast iron 69 heads and the car went 12.60 is a fully dressed 69 Mach....Hell for that matter i run a comp XE274 in my Pontiac 455...my grind is 230/236@50 & .488/491 lift ground on a 108....That little roller they picked for you should work well in a stock 351, duration is middle of the road and lift is good too....will work fine in iron heads or aluminum.

Comp ground my camshaft in my 408, and it seemed REALLY small to me with the AFR Heads...It spit out 550hp with that little roller and AFR 205's

So dont be afraid of that cam or the XE cams, just DONT GO TOO BIG, you will not like it....I would rather have a crisp fast revving motor that a top end screamer on the street any day.

Mike

[Powershift 19]

I would look at Ford Racing's selection of roller cams too. They have some nice grinds, for decent prices.

[1969 Mach1 14]

Even though alot of people don't like Ford Racing's small block Ford camshafts I agree with Powershift. Their X303 may be a good candidate. You may want to give them a call.

 

FYI. If you'd like a little more camshaft info Isky Cams has some good tech articles on their website. One in particular discuss the benefits and drawbacks of split duration camshafts (cams with more exhaust duration than intake duration), and when they should and should not be used.

Edited December 4, 2011 by 1969 Mach1