Author Topic: which cam would good for me? (Read 614 times)

pnandy · « **on:** April, 06, 2009, 12:23:07 PM »

need some help selecting a cam for my car
engine is 84 302 edelbrock intake gt40 heads with 650 demon carb
4 speed with 9inch 3.50 gears.

i need to buy new lifters cam and roller tip rockrs.
Im lookiing for suggestions as to what would be a good setup should i also be replacing other parts?
i engine was rebuilt about 4000 miles ago but nothing was matched up properly by the PO

i will be using a comp cam as my uncle can get me a good discount.

car is street driven

thanks for help in advance

Starfury · « **Reply #1 on:** April, 06, 2009, 05:52:49 PM »

Do you know what your compression ratio is? Do you know if the pistons have valve reliefs? Also, are you willing to change springs to accomodate a more radical cam?

pnandy · « **Reply #2 on:** April, 06, 2009, 06:00:32 PM »

have no idea what my compression ratio is or if pistons have valve relief i look through PO mess of receipts to see if he wrote that down when he got the engine built i'd be willing to change springs to

Starfury · « **Reply #3 on:** April, 07, 2009, 09:36:48 AM »

Ok, well, assuming you have no valve reliefs, I'd recommend either the XE256H with matching springs, or the Magnum 268H w/matching springs and 1.7 rockers. The latter will have the power band shifted a little higher.

If you have valve reliefs, The XE268H is a great cam. I ran it on my 331 for a while and liked it. It's a bit high winding, but you've got the gearing to get away with it.

pnandy · « **Reply #4 on:** April, 07, 2009, 08:22:04 PM »

didnt see a magnum 268h did you mean the magnum 270h http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=CC&Product_Code=31-414-3&Category_Code=SBHFTCM i found this kit in ebay watcha think
http://cgi.ebay.com/ebaymotors/COMP-CAMS-270-MAGNUM-CAM-K-KIT-FORD-289-302-K31-414-3_W0QQcmdZViewItemQQcategoryZ33614QQihZ010QQitemZ200278162889QQrdZ1QQsspagenameZWDVW
Also since gt40 heads use pedestal rockers what a good brand to go with as i can't find any comp pedestal mounting ones

Starfury · « **Reply #5 on:** April, 08, 2009, 10:18:36 AM »

Sorry, meant the HE268H. The Magnum 270H cam has quite a bit more lift and may cause valve-piston interference if you don't have valve reliefs. If you do, the XE268H is a better cam with a bit more lift.

A kit like that would work great, but you need to make sure the timing set is a full double-roller, as some of their kits come with crappy non-roller timing sets.

Comp Cams does have 1.6 and 1.7 ratio pedestal mount roller rockers. Part #'s 1052-16 and 1054-16, respectively. Crane also makes a decent 1.7 ratio set, commonly referred to as "Cobra" rockers because they came stock on Cobras. There's actually a set of those up on ebay right now.

pnandy · « **Reply #6 on:** April, 08, 2009, 12:10:41 PM »

i have the stock rockers from my gt40 heads but i thought it was a bad idea to use them on my setup becausue it wear differently.

Starfury · « **Reply #7 on:** April, 08, 2009, 01:58:54 PM »

You're going to want to pick up an adjustable pushrod length checker to make sure you get the ideal length pushrods, that way you avoid improper wear on any of the valvetrain components.

pnandy · « **Reply #8 on:** April, 09, 2009, 08:25:33 AM »

ya i figured that was the way to go instead of just buying the ones they link in the cam specs.

pnandy · « **Reply #9 on:** April, 15, 2009, 11:52:04 AM »

i posted this a couple days after i emailed comp cams for cam recomendation and they finally got back today with the same recomendation
XE256H

he also recomended a retro fit hydradlic roller cutome grind camshaft what should i go with?

Starfury · « **Reply #10 on:** April, 15, 2009, 04:51:18 PM »

Eh... It'd work great but would be really expensive, and you'd have to drill and tap your lifter valley for their spider assembly. I'm not a fan of doing that on an engine without tearing it down and cleaning it afterwards.