xbgs351

The machining on my short block is all done, and I will have 10.5:1 compression instead of my planned 10.25:1. The deckheight from the factory was allover the place.

I have ordered a COME CLS138 from COME but it has gone missing in the post.

I am now concerned that the cam is too small for 10.5:1 compression and I will get detonation. The cam specs are:
237/248 @50 thou
0.318/0.335 lift.
112 LCA

Should I step up to the CSBS 688?
243/249 @ 50 thou
0.344/0.350 lift
108 LCA

clevokid

Have got a 378 with 10.4 to 1 fitted with CLS108, it used to be ok on the old super with initial at 13 to 15 degrees. Probably depends on your end use of the car I`d say. Mine was an XC with small stall and 3.0 rear end. No probs on the street or strip with pinging. Ran avgas on the strip though so shouldnt be a problem anyway. If you ask Sam or Izzy they would be able to match the cam with what you need anyway.

xacoupe

I have 10.5 ish with a CLS108 and once I tuned it right and fixed a vacuum leak it didn't ping much at all. Whilst it is not a big cam it is big enough.
Would the rest of your combo be suited to the bigger cam if you went that way ?
I have the advantage of being about 2 Kms away from COME so I pick my stuff up.

brenx

I you were going a solid cam @ 10.5:1 Jeff's (xacoupe) cam is a nice cam. That should run on 98 octane fuel with no detonation what so ever.

What heads are you running? If they are alloy? The comp can be higher again. I've been running around on 91 octane with 11.2:1 comp.

Brenden

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XB Fairmont (street car) 11.07@123.02mph.

TD302

A cam with approx 240 @.050 can run up to 10.5:1 on PULP. I'll let you know soon i'm trying 10.6 with a 240@.050 cam in my 302. At the most a booster will be needed which isn't that bad for the gain of hp by upping the compression from 9.33 to 10.6. The Crane h296 needs around 10:1 to make the most of it anyhow. With alloys you can run approx 1 point higher compression with out any problems
Cheers Brett

__________________
California Speed Supplies
HOGG Performance (07)33764333
"Blocks and women are the same, if you got a good one it won't need a girdle"

qwikcorty

Im currently getting my 351 tuned, its running a similar sized cam, 238 246 @050 and 560 570 lift. And 10.8:1 compression. . . .
But ive also got multipoint fuel injection, so hopefully ill get away with premium .

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1976 351c td cortina

TD302

If not just use the race formula booster made by nos i've been told this works best for the money. I was going to use BP100 but told this mix ws better. That and ultimate is working on a 12.5:1 Chev with no probs at all.
QUIKCORTY hows the beast going. Is it off the dyno yet???

__________________
California Speed Supplies
HOGG Performance (07)33764333
"Blocks and women are the same, if you got a good one it won't need a girdle"

xbgs351

The cam in question is the same as Jeff's but with a 112 LCA.
I will be running 98 octane.
Heads are 65cc 302's
Block is zero deck
Manifold is Funnelweb
Carb is a Holley HP 750DP

I will speak to COME again tomorrow

xacoupe

A very similar setup to mine with the exception of the Funnelweb.. I will be interested to see what you think of it as I am considering ditching the performer ...

brenx

Yours is screaming out for a single plane Jeff

Brenden

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XB Fairmont (street car) 11.07@123.02mph.