[ponchorob]

461 build eagle stärker, edelbrock 61519 round port heads ..deckheight 0.020...calculate compression 11.1 ..race weight 3400....th 400 3.23 rear end....do You think its possibble to get was without Detonation with crower cam 60919...
and rhoads lifters also habe a lunati cam with 239/247 at 0.050 but with a not so good 110 LS for this compression.. what do you Think ..or better cam advice..thanks robert

[tom s]

What kind of fuel,should be no issue with race gas.Tom

[ponchorob]

...i have some Av Gas but want to know if its possibble to get was with 93 fuel...

[ponchorob]

Want to drive occasionally on the Weekend without race gas if its possibble with a little cam matching

[AG]

My race motor has 11.2 CR and I run 93 pump.

[Johnny406]

Is E-85 an option in your area?

[ponchorob]

..good idea .ill think its possible a few gas station have it ....what do i need for conversion. to eun e 85 ....Carb gaskets...?

[ponchorob]

......but still like to know if i can get away with a cam change a late intake closing valve. for example for lees dynamic compression.....but dont want to go any higher with a intake duration of 245 at 0.050 preferable less.....

[Jay S]

You left out some details that make a difference in predicting the outcome. The altitude or adjusted altitude, rocker ratio, the induction and the exhaust. I assume headers and 1.65 rockers, maybe a rpm intake? In my region, that combo with the 60919 would likely not work on 93.

I would need more info on the lunati cam to compared it to that Crower. Is it from their Ultradyne line? There are two things to “initially” consider when managing compression. One is the intake closing, the other is the intensity of the cam. Sometimes the effective rocker ratio is overlooked in regards to compression and its effect on the cams intensity. That combo with the 60919 with a bigger rocker ratio up into the 1.7+ would probably support a scr of 10.7 in my area on 93. For reference set of 1.5s might knock several tenths of scr from that. For off the self stuff, a melling 041 spec-8 would go a little higher. It has a little wider lsa and some more seat timing versus the 60919., it would be a little closer to 11.:1 scr. Still out of my comfort zone though. A 705 lunati widened to a 112 lsa might be close to working at that compression. Might want to talk to one of the lunati guys. With 11.1 scr, 3.23 gears and the Rhoads lifters it would probably be worth the time to do a custom cam.

[PAUL K]

Originally Posted by AG

My race motor has 11.2 CR and I run 93 pump.

Is that the engine in your "signature"?

[PAUL K]

You're borderline with either of those camshafts. One option would be to retard the ignition timing a few degrees. It'd also be a good idea to only use the Rhoades lifters on the exhaust side.

[AG]

Originally Posted by PAUL K

Is that the engine in your "signature"?

Yes it is, except it has a 499 ci shortblock now.

[ponchorob]

..jay... its a lunati cam partnumber 10510515.... running 1.65 on the intake and 1.6 on exhaust cause the heads valvesprings support only to 0.575 lift....... when running the crower 60919 i would use rhoads and 1.65 rockers or go to 1.73 harland sharp..

[ponchorob]

....also 1.7/8 roundport headers and rpm intake ....also have torker 2 but rpm is my first choice.....also thought about stepping up to a crower 60245 ....248/253 with 112 but maybe to much or to radical for street strip but maybe helps to get away....

[Jay S]

That Lunati cam you have is an Ultradyne profile. I used that Intake profile for a cam in someones e head engine about a month ago. I would pick that cam with the 1.65/1.6 combination rockers over the crower with the big rockers. I would have to do some calculating to see if that Lunati would work at 11.1 on 93. I think it has possibilities with the t2 and a spacer with that rocker combo. Maybe not if your racing on one of the coasts. I am assuming the t2 will shift the rpms a little higher and spread the cylinder pressure out slightly. Maybe the other guys have an opinion on that. Save the 60919 and the rpm for a lower compression combo imo.

Which type Rhoads do you have? I agree with Paul K on the exh only. Hopefully you ha e Vmax and just need tightening down on the intake.

JMHO, the bigger crower 60245 your looking at would get the job done. Looks a bit big to me though. Especially with 3.23, it might be slower than the lunati you have. Certainly safer on pump gas. It might not be bad with a set of and a good amount of lash., that is If you can stand to listen to the sowing machine factory.

[AG]

I ran an Ultradyne 255°/263° at 0.050" SFT on a 112° LSA in a 455, which is probably similar size to the Crower HFT you showed above, with 11.3 CR and ran 11.4 in a 3550# car. Motor used unported 16 heads that had 75 cc chambers, a TII and a 1" spacer. I used 2 gal of 110 octane mixed with 6 gal 93 pump., ran really well until a downshift into first at the top of second gear with cast rods.

[ponchorob]

Jay thanks for your long post ...i have only the originäl rhoäđś ďèśign.. your Suggestion to use the rhoads only on the exhaust i guess its for not further increasing cylinder pressure through the intake closing event....

[Skip Fix]

I run that Lunati /UD cam in my 455 pump gas motor in the '78 but on a 112 LS. "Normal" HF lifters. It does have dish pistons dropping me to about 10:25. Runs great on 93 even in the Texas heat.

[ponchorob]

Skip i know... your Combo ist my favourite because the w
eight and the mph you Run Shows good power with that cam thats why i choosed the cam but having the stock 110Ls...

[ponchorob]

I know you have better flowing heads and 3.9 or 4.1 gears but...the power with that cam is suffiecient and still street able in my opinion... skip do you have a cranking pressure Nummer on your motor..?