More cam for 1971, 318 engine

[74ChAARger]

I recently bought a 1971 Challenger project. It has the original 318 engine, now out of the car. I put the engine on a stand, it rolled over OK. I have a Hughes Whiplash cam I want to install in it and get it running. So I started the tear down. The 4 bl Holley carb and intake came off easily. The timing chain cover was a bit harder, but it came off. The timing chain was the original plastic gear type and very loose. I removed the cam to see what lift it had. Measuring the base circle and the lobe gave me .240 lift on the cam, 360 at the lifter with 1.5 rockers. Not much lift. Could be worn down some.

My question is will the extra lift of the whiplash cam cause any piston to valve problems. I pulled the heads and it has flat top pistons (.100 in the hole) with no valve reliefs at all. I have the Hughes valve springs I will put in the heads.

 

[moparleo]

Go with a 360. 318 is a low compression, small port/valve head. If you want the most bang for the buck. There are millions of used 360's out there with better heads and more cubes for very lttle money.The better heads will take advantage of the larger intake manifold ports and carb and cam. You will find that it will cost the same to rebuild a 318 or 360. The 360 will get you where you want to go for the same money.

 

[Chryco Psycho]

if the gross lift on the whiplash is under .520 you should be fine , you will need better springs , I would still measure the clearance

 

[74ChAARger]

The whiplash cam is .485/.518 lift , 213/226 duration at .50. It is called Whiplash 318, from Hughes engine, so they must have kept it under .520 for these engines. I have the cam and the matching springs, I was going to put in my 1979 Ramcharger removable top 4x4. My goal is to have a 360 stroker ar some time, but first the body work.

 

[74ChAARger]

I selected and sent for the Summit cam, SUM-6901. It has 441/441 lift and 218/228 duration at .050. A little more duration than the whiplash, so it should have that lumpy idle. The lower lift will give me room for a head shave, and let me get more compression. I will use the springs that came with the Hughes whiplash cam. This 318 had a single plane intake, I am hoping it will work with this cam. It is the low profile Holley Street Dominator single plane.