Topic: #62 Head Question

[80ws6ta]

I have a 1968 400 bored 0.030 over. I am trying to figure out what kind of compression it would run with stock pistons and a Ram Air IV cam. I currently have have 6X-4 heads on it now. The idle is terrible and I have no vacuum. Any thoughts?

[Mr. P-Body]

   The 041 (Ram Air IV) cam is designed for 10.5:1 compression (or higher). It is not suited to the 8:1 you now have.

   Did you have question about 62s? 6X is a later head and a much larger chamber, meaning lower compression.

Jim

[80ws6ta]

I know what I have to do. I'm going to change cams so I can actually drive my car. I have a 6X-4's on my engine now and it is a fight to keep it running. As long as it is higher in the RPM band, I'm fine and it screams. I have some #62's I was considering putting on my engine, but the compression would be too high to run pump gas. I decided to swap cams to the Comp Cams XE268H. That seems to be the cam I'm looking for. What do you think Jim?

[Mr. P-Body]

   We use XE262H as a "replacement" cam for the 068 and 744 versions in 400s when we reduce the compresion. We use XE274H as a "replacement" for the 041.

   XE262H would provide good drivability, reasonable idle quality, and strong torque through 5,000 RPM. Good cam. Not "rowdy".

Jim

[kjkjkcjkcj]

well the 62s were prob the original heads on the car because 62's were from a 68 400 motor. im running 62 heads and i bored my motor out 30 over and put in stainless one piece valves and had them ported a little as well. im getting 270 hp to the rear wheels and and about 360 torque which is pretty good i think for no serious modifications.  i am going to get a more aggressive cam to try and get a little more HP outa my motor. right now i have an XE240 cam i belive im not quite sure which one but its very mild, i am going to get the comp xe262 cam should liven my motor up a little bit.

[80ws6ta]

Jim,
  What do think about the XE268H? What is your experience with it and what kind of power could I expect? What kind of power could I expect from the XE262H? It just seemed to be more of what I had in mind for my car. I also intend to raise compression (some time soon) to around 9:1. What would you recommend with 6X-4 heads? I will be putting an adjustable valve train in as well.

kjkjkcjkcj,
  How does your car handle as a driver? Can you run pump gas?

[Mr. P-Body]

   The XE268H is the "red-headed stepchild" among Pontiac cams. It's too large for a stock converter, but the XE274H is a better choice if you have to change converters. XE262H will work fine with a stock converter.

   Milling the 6X-4s .060" will get you up to 9:1. Shorter pushrods will be called for.

Jim

[80ws6ta]

What converter should I use if I were to run the XE268H? What do you think about the XE262H? I have read some threads on Performance Years that said they didn't like the XE262H. I don't want anything radical. I called Butler and they told me to use either the XE268H or a Ram Air III. They said that either one would work great for what I'm trying to accomplish.

[kjkjkcjkcj]

i run high test.

[jphillips3333]

You can run the XE268H with a stock converter.  For the XE274H, they suggest a 2200+ stall

[80ws6ta]

Jim is right about the XE268H. There isn't hardly any information about other people using it. What I'm probably going to do is use my 6X-4's with the XE262H and I will eventually mill the heads to accomplish 9.0:1 - 9.5:1. Does anyone have any experience with this cam and/or combo? I'm kind of going for a Ram Air III set-up.

[jphillips3333]

I thought "bluex64" something or another ran the 268.  Comp cams says the stock converter with the 268 is fine in the specs they have listed. 

That said, I thought several people on here ran the 262 - maybe do a search for "262" and PM them to get their setup.

[80ws6ta]

I have heard a lot of good about the XE262H. I just haven't found any good reviews about the XE268H. Every thing I have found on the XE268H say that it is done at about 4800 RPM (that was from Cliff Ruggles on Performance Years). They all (including Jim and Cliff) seem to really like the XE262H.

[Mr. P-Body]

   Cliff dynoed an engine MANY years ago with XE268H. He didn't build that one. Many issues with that engine appeared, only one of which was the poor performance of the cam.  He really needs a new "story"... (:- CLiff's my friend, but this is one area we do not agree. XE cams are the best all-around performers we've found for "pump gas" engines, bar none. In smallblock Chevys, XE268H is a VERY popular grind.  All depends on application and "execution".  I base these statements more on customer satisfaction than dyno numbers, too. Those at the level that would use such a cam, aren't interested in racing dynoes... They want to DRIVE their car!

   Comp says "2000 stall" for XE268H. That's in the catelog, anyway.

   We use XE262H almost exclusively in engines such as the 366 HP Ram Air III, when we reduce compression to use 93. We use it in any application that had 068 or 744 as "stock".  We've installed no less than 50 in the last 9 years. Zero failures, zero unhappy customers.  We have a couple TriPower GTO guys that can't believe their 389s run the way they do. Stock intake and exhaust, 275 RWHP and 18 MPG...  It IS "doable".

Jim

[80ws6ta]

That is  what I kind of figured after I found his post on Performance Years. I think I will go with the XE262H. I have noticed that everyone is happy with that cam. It definitely seems to be a great driver cam. What kind of compression and rear end gearing does it like? Also, what lifters and springs would recommend?