It sounds like you have more than enough info to make the right decision. I ran cranes 168761 in my 60 over 502's(8.6 comp) with good sucess at 6 pounds of boost and stock iron head with a bowl job, 420 b&m(no intercoolers) and a pair of modified 750s we pulled an honest 700+hp and over 700 pounds of torque at 5800. These motors were far from lazy. 230-236/ 598-610.

Good luck,

Mike

Obnoxious Thundr,
If you have the opportunity, try the 741. You will be glad you did!!!

Tim,
the 741 is the way to go. I had it my 502 and liked it very much

Like you said, Crane reads off a sheet when you call them. I called to see what they would suggest for my 598 (out of curiousity) and that's the cam they said to use.
I said on a blown 598???!!!!
"oh ya, you'll have great torque...blah blah blah"
I just said "ok, thanks" and hung up because I knew there was no sense in arguing.


DAVE

Just for kicks does anyone have a solid roller recommendation for this motor? I cannot relate to these hydraulic roller cams. I have never run one. I know a hydraulic flat tappet cam in the 244 duration at .050" and .550" lift is a pretty healthy cam, but if the same cam were in a solid roller it would be real wimpy. Maybe this would be a better scenario. I run a 272/280 duration cam @.050" with .714 lift on a 112 + 4 installation in my 498. What hydraulic roller would give a similar shaped tq/hp curve and control my cylinder pressures generated by 13.2:1 compression just as well and still idle. I am not buying a hydraulic roller anytime soon, I am just trying to learn. I currently run the motor over 6000 RPM and if that is a problem with hydraulic cams lets say I can live with 5700 or 5800 RPM. How much HP diff?
Thanks
Craig

Dave,

I know what you mean about the "reading off a sheet". I am sure that there are some very competent people there, just depends who you get. When I was quizzing them about the merits of the 741 vs. the 731 I was very clear I was running a blower. He told me the 741 did not have enough compression for the 741 and if I were to raise my CR to about 9.75 I might be ok. Lets see 9.75 to 1 with 5lbs. boost. How long would that engine live?
Tim T.

It would not live long on pump gas !!!!!
The 741 is killer for a blower we have used countless ,for real !!

Advance it 4 degrees and hang on ,you need to make about 7 lbs of boost and pump gas The blower will handle the comp. issue ,the guy must not have heard you say blown motor :D :D :D

Tim,
FWIW, Mine was installed straight up. 0 adv.

One word of experience, when I installed the new timing chain/gears with the adv and ret keyways, I was geeting a very fine oil fling from the balancer area. 2 yrs of looking for a leaking balancer seal or leaking timing cover gasket, only to find that was not it. Oil was finding it's way past the keyway somehow and out the balancer. After you reinstall the balancer, fill the key way with RTV before you put the washer and crank bolt in. No more oil flinger.

Vette,
For the 502 cube blower motor, a comperable solid roller cam, in my opinion, would be the Crane 138551.
It's a 238/246 112 .595/.615
Open/close @.050:
Int/Ex
12/46
60/6
Compared to the 741 hyd roller:
236/244 112 .610/632
11/45
59/5

Now, for your motor:
If it were a Gen 6, the biggest one in the catalog is:
168771, 240/248 114 .621/.632
11/49
63/5

For a Mark 4 block however:
The biggest one in the catalog is:
139661, 256/264 114 .632/.632
19/13
71/13

I think the 661 aughta do it
:D

DAVE

Wette Vette/

A couple years ago I ran the Crane 13R0003216 solid roller , 112, .714/.714, 262/270 with 1.8 rockers and made 750 @6700 in a 500 in natural motor, w/big chief heads. Went to a Crane 13HR00036 hyd roller with 112, .632/.632, 264/272 and 1.7 rockers and made 650 @5400 in same motor. Crane purposely tried to duplicate the soldi roller performance in a hyd and this cam did real well for a hyd roller.

My 502 with dart 360's with the combustion chamber worked and bowl ported by JimV with the 168771 a 250 blower 2-750 holley blower carbs made 700.0hp @5800 the brake was .55. This is a stock merc dist. and a msd 6, 30 degrees of total timing. This was 6.5 lbs, the static comp is 8.3 to 1.By the way the crane guy told me any Hyd. roller with .575 lift using 1.7 rockers needed to use aftermarket roller lifters. I have the carbs and linkage and top plate for that blower for sale. Good luck with your project. J