EngineQuest EQ head build March 2012

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femtnmax

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EQ heads for a street 360. Valve sizes used were 2.02/1.60 intake/exhaust. The EQ heads on the outside look identical to RHS, without the “RHS” logo. Bought most of the parts from the local machine shop, their prices were equal or better than summit, and no shipping charge.

Intake port throat diameter: according to Speedtalk advanced tech, throat diameters approaching 90% of valve diameter make great flow bench numbers, but torque recovery and track performance improve if the throat is smaller. The as-cast intake port throat diameter just below the valve seat measured 1.7 inch, which was 88.5% of an OEM Mopar 1.92 valve diameter. For the 2.02 valve O.D. the throat was enlarged to 1.76 inch diameter for 87% of valve O.D.

Pushrod pinch limiting port velocity: EQ pinch measured .875 avg width x 2.3 height =2.00 sq.inch. For comparison, widening the pinch to .935 inches gave 2.15 sq.inch of port area. According to the speedtalk forum, the maximum preferred limiting port velocity is Mach 0.55 = 615 ft/second at sea level.
The as-cast EQ head port velocity at the pushrod pinch =
(.00353 x 6000rpm x 3.58stroke x 4.03bore squared) divided by 2.00 sq.inch = 616 ft/sec. So the as-cast intake port pushrod pinch is good for around 6000 RPM.

Peak torque RPM = (2.00 sq.inch pinch x 88200) divided by 47.75 cu.inch one cylinder.
Peak torque RPM = 3694 RPM. The 2.15 pinch area has peak torque at 3970 rpm.

After the valve job and unshrouding the valves, the combustion chamber volume increased from 58cc to 64cc. The chamber cc’s were further increased by unshrouding the combustion chambers a little closer to the gasket line, and adding an angle to the quench area between the spark plug and intake valve shrouding to obtain 68cc for 10:1 static compression with flat top pistons at .004 below deck height. The valves were unshrouded to fit a Felpro Q1008 head gasket which has a .039 compressed thickness.
Final part numbers and cost include:

Pair of heads from AAmidwest:
http://www.aamidwest.com/files/file/EQ_2010_2011Catalog_sm.pdf
Part number Ch318B with LA style intake manifold bolt pattern. Weight 49 lb each.
Cost each $239 + $25 shipping. Total: $528

Valves from Scorpion Performance:
http://www.scorpioncheckout.com/SearchResults.asp?Cat=149
Corvette LS1 intake valve: 2.02 diameter, 8mm stem, 5.0 length
Part number: SRP06, set of 8, cost $98.95
http://www.summitracing.com/parts/SCC-SRP06/
Corvette LS1 exhaust valve: 1.60 diameter, 8mm stem, 5.015 length
Part number: SRP31, set of 8, cost $97.95
http://www.summitracing.com/parts/SCC-SRP31/
Cost for 16 valves plus shipping from Summitracing Total: $209

Valve springs:
Comp Cam beehive spring 26981-16
110 lb seat load @ 1.70 installed height, 293 lb @ .528 lift, 347 lb/inch, 1.115 coil bind.
At .528 inch valve lift coil bind clearance is 0.055 which is still acceptable.
http://www.summitracing.com/parts/CCA-26981-16/
Cost $147 from local machine shop. Total: $147
The valve guide boss diameter at spring seats needs to be reduced to use the 26981 springs. The valves were NOT sunk in the ports when doing the valve job; like some shops are doing to obtain the correct spring installed height. Instead the LS1 valves have longer stem lengths than OEM, and the seats were cut just enough to make the seat pattern. Shims were added under the springs to obtain the 1.7 installed height.

Valve spring retainer:
CompCam part 774-16 for GM Gen III, 5/16 valve stem, 7 degree.
http://www.summitracing.com/parts/CCA-774-16/
Cost $52.95 from local machine shop. Total: $53

Valve locks:
Comp Cam 623-16 for LS1, beadlock, 8mm stem, 7 degree lock
http://www.summitracing.com/parts/CCA-623-16/
Cost $30.50 from local machine shop. Total: $31

Reamed and honed the guides from 5/16 to 8mm, and cut the valve seats in heads. Final geometry has exhaust valve seats 0.02 below intake seats. Smokey Yunick in his book “Power Secrets” suggests locating the exhaust seat .03-.04 deeper in the port than intake to reduce pulling the intake charge out the exhaust port during valve overlap. 4 angle valve job $160, ream and hone guides $50, unshroud valves and reduce guide boss diameter N/C.
Machine shop labor cost: Total: $210

Valve seals:
Positive intake seal (Mopar 318/360 magnum part): SS 72844 @ 10.50 for 8
Umbrella style exhaust seal: VS 232P @ 0.79 each = 6.32. Total: $17

Total cost for two heads: TOTAL: $ 1195
The cost is more than a set of pre-assembled heads, but I know each part and know the valve job and guide clearance is correct. Maximum valve lift for this combo is .530 inch.

OTHER PARTS TO COMPLETE THE BUILD

Rocker arm studs: CompCam part 4542-16. Total: $72
http://www.summitracing.com/parts/CCA-4542-16/

Pushrod guide plates: CompCam part 4825-8. Total: $28
http://www.summitracing.com/parts/CCA-4825-8/

Rocker arm polylocks: Pioneer part S-1010. Total: $28

Rocker arms: CompCam part 1416-16, 1.6 rocker ratio. Ebay. Total: $147

With the valve closed, the #1416 rocker arm roller tip contact pattern on the valve tip started .05 from the rocker stud side of valve stem centerline. At max valve lift the roller was .05 from centerline on the exhaust side of the valve tip for a total contact sweep of .10 inch. At max valve lift the roller tip contact was at the dwell point just prior to sweeping back toward the intake valve centerline. I will fine tune the rocker contact when sizing pushrods. So don’t listen to the sales pitch from some of the EQ suppliers that Chevy rocker arms won’t work. AAmidwest said they would work and they are correct. I had a local machinist (a dirt track racer) ask his Mopar friends what rocker arms they were running with EQ heads…Chevy rockers was the reply.
I tried a Crane Nitro 1.6 ratio stamped steel rocker. With the valve closed the rocker contact was set just within the valve stem. Then increasing valve lift had the rocker “rock” across the valve tip just like OEM non-roller rockers; the contact moved to the opposite side of the stem to the very edge of the valve at full lift (.530 lift). A larger diameter valve stem would have allowed a little more clearance between rocker contact and valve stem O.D. Smokey said you want 0.020 inch minimum. Checking with a magnifying glass I wasn’t confident that I had at least that minimum amount so I went with the Comp rockers. I could not “start” the Crane rockers any closer to the stud side of the valve stem because the rocker arm body was about to hit the polylock.
 
Finally have time to get the heads on the engine. Changes to the parts list:
With the taller valves need to use Ford 302 rocker arm studs. The Mopar studs are too short and the rocker arm trunion was riding on the threaded shaft instead of the non-threaded shoulder.
Second item is the Pioneer poly locks have 0.32 inch of non-threaded shoulder at the bottom, where the geometry needs threads to the lower end of the poly lock to have the preferred number of threads engagement (equal to the diameter of the stud). So ordered ARP poly locks.
Last item is the pushrod length worked out to 7.75 inch for EQ head on LA short block with hydraulic flat tappet cam and Comp Magnum ball pivot roller tip rocker arms. This pushrod length puts the rocker tip contact at valve stem centerline when valve closed, then contact moves 0.07 inch toward the exhuast side of stem at full lift, which is still .08 inch from outer edge of valve stem.
Full roller rockers would have needed a taller rocker stud which would mean going to rocker stud with 3/8 base thread. We then did an experiment on a cracked mopar OEM head, threaded the head for both 3/8 and 7/16 rocker stud base threads. The 3/8 threading left telltail signs of the old 5/16 threads, which was a concern, but a bolt was inserted and tightened to 50 ft lb before the cyl head threads started to deform...this is well above the 30-35 ft lb torque needed to secure a 3/8 rocker stud. So threading the 5/16 stud holes to 3/8 inch is a good option. The 7/16 hole left not much material between the hole and casting surface, in fact the remaining material was 50% less than if the same procedure was done on an OEM chevy head. IMO EQ left out potential customers by not adding about 0.07 inch of material radially to the meat around the rocker studs.
Should have the engine running in a couple weeks when I'm back in town from work.
 
Photo is of 68cc combustion chamber. After polishing the chambers the volume was 62cc. Then the valves were unshrouded as much as possible, followed by enlarging the chamber below the intake valve at the bottom of pic. This last cut removed metal from the thick deck of the casting, but did not thin the casting of the combustion chamber. Pistons are flat top with 5cc valve reliefs set at .004 below deck for static compression ratio of 10:1, and dynamic ratio of 8.4:1.
Head gasket shown is Felpro #1008 with 0.039 compressed thickness.
 

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  • sm_EQ heads 68cc chamber volume.jpg
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Thanks for the encouragement.
Finished assembly today, ran the engine for 25 minutes to break in the cam, set total timing at 34*, then took the Challenger out for 20 miles on the road pushing thru the rpm range. The engine ran good with no issues.
Tomorrow I'll runs the roads again after removing all the pushrods to check for any rubbing on the cylinder heads...during mockup the pushrods were running close to the backside of the intake gasket surface so did a little grinding at each location for clearance (LA flat tappet lifters locate the pushrods closer to the cyl head).
Also during mockup the longer rocker studs (Ford 302) have too long a base thread, so shortened all the base threads to .58-.6 inch length, locktited them in the heads at 23 ft lb torque. The rockers road real well on the longer rocker studs, the ARP polylocks fit nicely with more than enough thread engagement and did not have to engage the hex lock nuts too deep. So geometry and final fit was real good IMO.
Will be able to verify rocker tip contact/sweep on the valve stems too.

Parts that were swapped/added to the original list:
Rocker arm studs: Comp 4504-16, have 5/16 base thread & 3/8 rocker thread.
Pushrods: Comp 7644-16, with 7.75 inch length for LA short block & magnum heads.
Polylocks: ARP 300-8241. With the cam on lobe base circle, took up all pushrod freeplay, set the polylocks at 1/3 turn in, then tightened the hex adjuster and polylock main body turning them together for full tightness at about 1/2 turn in.
I kept the Comp magnum roller tip rocker arms. For full roller rockers may need to drill out the heads for rocker studs with 3/8 base thread...mainly because there is more selection of rocker stud lengths.

The car is a street driven heavy Ebody Challenger, 3800 lb with driver, 3.23 axle gears and 4 speed. So needed good low-mid range engine torque; the EQ heads intake port shape should help torque. The old cam was 218* @ .05 lift which had great mid-top end, but the engine surged when slowing down to turn corners in 2nd gear...so changed to 215* .05 duration and that fixed the problem (I was keeping in mind the OEM 340 cam had 210*).
After a few more miles on the engine I'll get into the carb secondaries and see how the overall performance is. I'm pleased so far with the results.
Hope all this helps someones engine build.
 
I love ,your attention to detail.You have the scrutiny,of a machinist,or a Super Stock racer.This knowledge ,comes from somewhere.(lol).
 
Tightened most all fasteners, removed and inspected pushrods and rocker arms. Everything checked out OK, so put another 100 miles on the car today. Here is a pic of rocker arm valve stem tip contact. Contact area is .07 inch wide, and stops .05 inch from exhaust "side" edge of valve. Smokey Yunick said to keep the contact pattern at least .02 inch from edge of valve, so I'm ok there. He also said not to fuss too much over centering the pattern on the valve tip; it is more important to have the smallest pattern sweep across the tip. Moving the contact closer to centered on valve stem increased the contact pattern width and reduced the total valve lift, so I stayed with the most lift possible and narrowest pattern. Last pic is the car on the road in Yellowstone Park last summer.

View attachment sm_EQ rocker arm geometry 004.jpg

View attachment sm_sm_Buffalo in Hayden valley2.JPG
 
femtnmax said:
For full roller rockers may need to drill out the heads for rocker studs with 3/8 base thread...mainly because there is more selection of rocker stud lengths.
Click to expand...

There is another way to go. Eliminate the studs all together and use either Harland Sharp or Hughes rockers. They bolt directly to the head using ARP bolts through the rocker and have a machined pedestal underneath each rocker arm and have rocker pairs tied together so there's no need for pushrod guides. I am using Harland Sharp's on my EQ heads and they bolted on with no mods and have really good geometry. I have not had the oppertunity to see the Hughes rockers in person but here their really nice and produce great geometry also. Here's some pics of mine when I was mocking it up.

View attachment DSC02066-1.jpg

View attachment DSC02070-1.jpg

View attachment DSC02067-2.jpg

View attachment DSC02068-1.jpg
 
Nice setup,Fishy.Didn't know,H.S. did a Magnum setup,looks nice.
 
1wild&crazyguy said:
but what do these heads flow??
Click to expand...

I believe their in line with RHS heads. Here's what mine did OOTB and with some port clean up, bowl work, and chamber relief. My worked numbers aren't all that impressive but I'm just an amateur with no flow bench. I had to do the work then drive them 40+ miles to have them flowed to see what gains, if any I made. I wasn't building a race car so the worked #'s suited me so I didn't go any farther.

OOTB/Worked

---Int---------EX---
.1-68/67 52/56
.2-133/140 106/109
.3-193/201 148/150
.4-235/246 176/182
.5-252/265 182/192
.6-240/268 182/198
 
340sFastback said:
Sounds like a great build. How about a video of that bad boy?
Click to expand...
Finally, here is a video of the engine with EQ heads and a short road test.
[ame="http://www.youtube.com/watch?v=Gxcygx54T-0"]360 Mopar Engine July 2013, MT - YouTube[/ame]
 
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