Looking for engine package recommendations

General engine tech -- Drag Racing to Circle Track

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406shark
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Looking for engine package recommendations

Post by 406shark »

I tried to give as much information as possible... hopefully not so much that you get bored reading. lol

Dart SHP block
Eagle forged crank
Eagle forged H beam rods
4.155” x 4.00” – 434
JE 182031 Pistons – 10.8 cc dome, double pin oilers, gas ports, 1/16x1/16x3/16 ring pack
King HP bearings
Compression 13.85-1
Holley Strip Dominator Intake – 300-110 version
Pro Systems 950 carb – sheet shows it flows 830cfm
1.750” – 1.875” – 3.5” collector coated headers
Comp Cams belt drive
MSD Crank trigger with MSD Pro billet locked out distributor
Daytona Sensors CD-1 ignition system.
Turbo 400 – transbrake --- 6000 rpm stall - drops back to 6100 shifting at 7200
Fab 9” with new 3.89 gears
CM round tube chassis – weight at the starting line = 2340

My current cylinder heads are Brodix Track 1’s with “street/strip” port and chamber work. Chambers are 69cc. The following flow numbers were taken at 28” with a 4.000” bore. The valve springs are good to .700” lift.

Intake
.100 – 70
.200 – 158
.300 – 218
.400 – 261
.500 – 290
.600 – 311
.700 – 315

Exhaust
.100 – 57
.200 – 113
.300 – 178
.400 – 209
.500 – 232
.600 – 242
.700 – 248

I realize the heads are small for this cubic inch engine, but they are what I have. I was running all of this on my old 383 until I hurt it. Then threw the parts on an old 355 shortblock and ran 9.90’s. Got a good deal on this 434 shortblock, and I’m going to attempt to make it run as good as I can until I save up enough for new heads, cam and carb to make it all work together. I have the cam from the 383 (Harold’s grind) and the cam from the 434 short block (Comp). Here are the specs on both. Which do you think would work best. 1/4 mile racing 75%, 1/8 mile 25%.

Harold/Lunati camshaft

271/278 @ .050”

.684/.684 lift with 1.5 rocker

106° LSA

29 ATDC
69 BBDC
33.5 BTDC
57.5 ABDC

Lash hot .014/.014



Comp Cam

276/284 @ .050”

.630/.630 lift with 1.5 rockers
.672/.672 lift with 1.6 rockers

107° LSA

54 ATDC
88 BBDC
49 BTDC
83 ABDC

Lash hot .020/.022



Thanks,
Jeff
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Re: Looking for engine package recommendations

Post by randy331 »

Got room to run a 1.6 rocker on the Harold/lunati cam?

I like the lift of that set up better.

Randy
406shark
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Re: Looking for engine package recommendations

Post by 406shark »

Thanks for the response.

My springs are from Brodix. Part number GA 1000.

They are at:
1.950" - 250 pounds
1.250" - 600 pounds
Coil bind at 1.160

I don't think the 1.6 rockers are going to work with the Harold/Lunati cam. It would end up at .730". The valve train quit at 7350 rpm with the current setup.


Guess I should have put this in the political section with a title like, "should I choose Trump or HRC"? I probably would have multiple pages of responses. lol

Thanks again,
Jeff
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Re: Looking for engine package recommendations

Post by cgarb »

That's kind of a tough one...I think if it we're mine I would maybe stick with the Harlods cam. Should make plenty of torque with that one.
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Re: Looking for engine package recommendations

Post by cjperformance »

Are valve events listed for each cam taken at the same point?
Craig.
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Re: Looking for engine package recommendations

Post by 406shark »

cjperformance wrote: Fri Jul 20, 2018 6:15 pm Are valve events listed for each cam taken at the same point?
I took the numbers from the Comp Cam site. Shows them at 107°. Cam part number is 12-996-9

http://www.compcams.com/Company/CC/cam- ... d=372&sb=2


The numbers from the Harold/Lunati cam show them at 4° advanced = 102° I believe.

Image


I honestly don't know enough about cams to know how to compare the events, or if they can be compared with the center line being different. That's why I posted them for someone smarter than me to help.



Jeff
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Re: Looking for engine package recommendations

Post by 6.50camaro »

I would use the lunati cam for the following reasons . More gross lift , tighter lash = more net lift . The slightly shorter duration could be better with the track1' s . The 106 LSA could work better with them also ,if you use DV 's rule of thumb 128 formula . Dan
That last comment was to see if just mentioning DV and the 128 formula sparks controversy .
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Re: Looking for engine package recommendations

Post by cjperformance »

406shark wrote: Fri Jul 20, 2018 6:45 pm
cjperformance wrote: Fri Jul 20, 2018 6:15 pm Are valve events listed for each cam taken at the same point?
I took the numbers from the Comp Cam site. Shows them at 107°. Cam part number is 12-996-9

http://www.compcams.com/Company/CC/cam- ... d=372&sb=2


The numbers from the Harold/Lunati cam show them at 4° advanced = 102° I believe.

Image


I honestly don't know enough about cams to know how to compare the events, or if they can be compared with the center line being different. That's why I posted them for someone smarter than me to help.



Jeff
The Lunati events are based off of .050" and the comp are based off of advertised duration . You would need to map the comp at .050" to get a better look. The .200" numbers tell some more again.
Based off of the numbers available I would use the lunati in this one.
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Re: Looking for engine package recommendations

Post by 406shark »

Thanks for the responses.

Where would it be best to install the cam from Harold? Would it be best to start with the 102° like he suggested for my old 383, or more toward the 106°?

I'm not sure how much "low end" power I'm going to need with using a turbo 400, not to mention the fairly high stall converter. I changed over to 3.89 gears with the expectation of running quicker and with a higher MPH.




Jeff
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Re: Looking for engine package recommendations

Post by Newold1 »

The Harold/Lunati cam, some good 1.6 roller rockers, and some better valve springs with more lift range (look at Conicals). It's a Lite ride that will need some tweaks to hook up and pull but more rpms will get it done. JMO
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Re: Looking for engine package recommendations

Post by 6.50camaro »

IMHO, I would start at 104° and go from there. With belt drive if it's the open type it's not that big of a chore to change . Not like a timing chain or gear drive. I think your right about not being to worried about low end torque . Although, I would try to find a converter that stalled about 500to 600 rpm less with the 7200 limit on the valve train.
Just my thoughts. Dan
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Re: Looking for engine package recommendations

Post by cjperformance »

Doesnt really matter where you start with icl, 104/106 will be fine, just check piston/valve clearance 5 deg either side so you know you can change easily if you want to. It wont be short on tq thats for sure.
Load that belt drive when you set the cam to simulate some running load.
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Re: Looking for engine package recommendations

Post by 406shark »

Thanks guys.

Yes, the belt drive is the open version. I'm going to install the Harold/Lunati cam with the 1.5 rockers at this time. I'll check for PTV clearance and start at 104° install. I'm going to pull the 355 apart in 4 weeks and move the parts over onto the 434. I'll be testing the 434 when I'm down in Tennessee that week. I know that based on my race weight and the MPH/ET I've been running what the 355 makes power wise. It'll be interesting to see what adding all those cubic inches do for the MPH/ET running all the same parts other than short block.

I may end up getting new and bigger heads and carb over the winter to be able to make more power. Right now I just want to get the most out of what I have on hand.

I have a friend that runs the same setup I do as far as chassis and modifications, his weighs 45 pounds more than mine. I'm going to change up my 4 link settings to get it where his is, cause I know his works running 5.50's in the 1/8th. That should save some testing at the track, initially anyway.

I'll update this thread once I have some results.



Thanks again,
Jeff
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Re: Looking for engine package recommendations

Post by midnightbluS10 »

There's a company that makes a 3d-printed, carbon fiber type cover for the Jesel belt drive. I wonder if it would fit the comp setup? They appear to be very, very similar. Anybody know if they're that much different?
JC -

bigjoe1 wrote:By the way, I had a long talk with Harold(Brookshire) last year at the PRI show. We met at the airport and he told me everything he knew about everything.It was a nice visit. JOE SHERMAN RACING
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Re: Looking for engine package recommendations

Post by GARY C »

Cam from a 355 going into a 434? Doesn't the 434 need a small base circle?
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