[65blueyes]

Ok I have three questions to ask... First of my engine is a 1969 302 with 1974 iron heads.

1. Eventually I'll be switching my stock 74 heads for the AFR 165's. At the same time I want to swap my mild hydraulic cam for something with a little more performance in it. I was thinking about a mechanical cam instead of hydraulic. I was searching around and cant find many mechanical cams for small block fords, any particular place to look? I want something that would match those AFR heads Holley 600 carb, and my Edelbrock Performer RPM intake.

2. Do they make a mechanical roller cam? If so how hard is it to upgrade my block and valvetrain to roller stuff? And is it expensive?

3. The last question is right now my compression is 8.5:1, with those new heads with chamber of 58cc, how much more improvement of the compression should I be expecting?

Thanks for your info!

 

[LMan]

1. Theres no need for a mechanical (solid) cam, unless you are dying for that rattle of solid lifters. Mechanical cams are for the highest-stress racing where absolute valvetrain rigidity and accuracy are a must; for street driving and mild-to-moderate racing they are unecessary. Todays hyd cams do just fine. Now if you are talking a 5.0 style roller cam, an argument can be made for that...up to a point. If you want to go that way and you are rebuilding your motor, I would suggest starting out with a 5.0 roller block rather than invest in a retrofit kit. My PERSONAL opinion, a good hyd flattappet is just fine up to serious-hobbyist levels of racing. Others will disagree ::

2. see #1. Your $$$ is much better spent in the heads and other areas. Its in the heads and exhaust where you will find HP in the small block Windsor.

3. First, how do you know your compression is 8.5? I dont know thats true that you will gain comp...you may LOSE compression compared to your stock heads, there are too many variables not spoken of here. Stock heads are small chambered, I dont recall the cc of a 74 head, but its not much. If its less than 58cc you will drop compression if you dont change piston type/height or anything along those lines. If so you may need to mill the heads, change pistons, or something similar to get the CR back up. You will want b/w 9.5 and 10.5:1 to live on street gas and perform well.

 

[blkfrd]

Comp makes mechanical flat tappet and roller cams. I chose a Comp 282S flat tappet mechanical cam for various reasons. One reason was that cobraautomotive.com uses that cam for their street 375HP 289s. A hydraulic Comp 280H would be a good choice for performance in a hydraulic cam if you change your mind. The 74 heads were probably large chamber heads with something more than 60 ccs. Mill the AFR 165s to get your compression up to at least 9.0 preferably something in the high 9's would be better with a performance cam having >= 230 duration @ .050. You can do the roller cam retrofit thing for about an additional $400 or so.

 

[Cosmo]

Why do you think your compression ratio is 8.5 ? The 69 302's for which I have data show 9.5 - And it really matters when it comes time to select a cam. The 1974 heads probably have 58.2 cc chambers, so you'll want to go with 58 cc AFR 165's.

If you really do have 8.5-1, you want a small cam at best or you'll bleed off what little compression pressure you do have. Perfect for nitrous or supercharging , but not with stock pistons.

If I were you, I'd do more research before setting a budget. I think you have more to do than you realize. Don't give up though! You came to the right place.

 

[65blueyes]

I always thought that the 1974 heads had larger chambers in the mid 60cc's or so. I could be wrong! THe builder of my engine told me my compression was 8.5:1, so I am going off that. I go the longblock for $1100, and I couldnt pass up that deal. I will prolly need to change pistons for some higher compression ones. One more thing... would i be able to do that without boring out the cylinders again? I only have 15k miles on a .030 over. Thanks for your help I appreciate it alot.

 

[LMan]

no, the 69- ~74 351W heads are in the 60-64cc range, thats why they are used on 302 blocks for a cheap breathing upgrade. In ~1975 Ford started to put the 302 heads on 351W blocks, so that advantage was lost.

I am scratching my head tryin to figure why a builder would deliberately set the CR at 8.5:1 for a NA engine. Maybe its arcane black-magic Dwarven machine-shop lore that Im too ig-nert to divine, but IMHO thats mid-70s strangled-smogger-motor territory, you DEF want to up that to 9-10:1 (if what he said is true).

 

[65blueyes]

Thanks for your reply... I am still a little confused though, my heads are 302 heads stamped in 1974 and they have the smaller spark plugs. So the cc range is 60-64? or is that just for the 351W heads?

I was thinking about supercharging, but I'd rather go all motor, and it would be a little bit cheaper.

Thanks for your clarification!