[shoebox1.1]

I’ve personally not run a summit cam but my Pontiac buddies have relied on them for years and always had good running cars.

[TransAm 474]

Jay,

When you say the 2802 cam needs a couple extra degrees of Advance due to the bigger exhaust spread, do you mean it needs to be advanced a couple degrees from the 109° Intake Centerline the cam card states,(which would be 107°)or are you just talking about the advance that is already built into the cam, and should be installed at 109°?

[Jay S]

They are suppose to come with 5 advance like you said. 109 will be a good place to set it at.

[Jay S]

We usually install the 10 degree split cams with the 112 and 114 lsa on 108.

[TransAm 474]

Originally Posted by Jay S

They are suppose to come with 5 advance like you said. 109 will be a good place to set it at.

Awesome, thanks! How do you think the cam will behave in a 9.8-1 engine? Strong low end? We are looking at the Hughes GM25 converter for it, car has 3.55 gears, Th400.

[Jay S]

If you have them talked into doing a 2500 stall that should take car of any lack of bottom end power the 2802 lacks.

In the mid 220s it has always seems like cam options are slightly limited for off the self stuff. The other cam similar to the 2802 is the crane 278/290 222/234 114lsa, .467/.469. Several members on here run it. It should have a little stronger bottom end power than the 2802, might even oust or come close to the 60916. Mainly because that crane is has less seat timing than the summit and is 5 degrees asymmetric, versus the summit and the crower are symmetric profiles.

The crower and summit cams the opening rates and closing rates are the same, versus the crane has 5 less degrees on the opening side versus the closing side. Plus the 278 rating is “suppose to be” at .004 tappet (I question some of their ratings since Harvey Crane left, some of their profiles look like .006 now). Not a big difference on the asymmetrics, but the 278 crane would have a little better vacuum and bottom end every bit as good of top end. I have done more engines with symmetrical cams, but the last several years we have been using asymmetric profiles and running bigger profiles on the higher compression stuff. Thought I would mention the 278 crane, for the lift, duration, wide lsa, and being asymmetric grind, it has a well designed cam. Bang for the buck, summit grind is great though. I would do the crane before the 60916 at 9.8.

[chiphead]

What are the Intake Closing points on the 2802 and the Crane 278, based on advertised numbers and installed per cam card?

[TransAm 474]

Originally Posted by Jay S

If you have them talked into doing a 2500 stall that should take car of any lack of bottom end power the 2802 lacks.

In the mid 220s it has always seems like cam options are slightly limited for off the self stuff. The other cam similar to the 2802 is the crane 278/290 222/234 114lsa, .467/.469. Several members on here run it. It should have a little stronger bottom end power than the 2802, might even oust or come close to the 60916. Mainly because that crane is has less seat timing than the summit and is 5 degrees asymmetric, versus the summit and the crower are symmetric profiles.

The crower and summit cams the opening rates and closing rates are the same, versus the crane has 5 less degrees on the opening side versus the closing side. Plus the 278 rating is “suppose to be” at .004 tappet (I question some of their ratings since Harvey Crane left, some of their profiles look like .006 now). Not a big difference on the asymmetrics, but the 278 crane would have a little better vacuum and bottom end every bit as good of top end. I have done more engines with symmetrical cams, but the last several years we have been using xasymmetric profiles and running bigger profiles on the higher compression stuff. Thought I would mention the 278 crane, for the lift, duration, wide lsa, and being asymmetric grind, it has a well designed cam. Bang for the buck, summit grind is great though. I would do the crane before the 60916 at 9.8.

Thank Jay, that is some great info. We will probably definitely end up going with the Hughes GM25, because we are building his TH400 as well to go along with his new engine build, and it will have to have a new converter anyway, so the difference in price is not much over a stock replacement unit. We ordered most of the enfine parts last nught, we went with the Icon IC891-030 pistons and Summit 2802 and 68404 Crower springs.

[Jay S]

Cam card says 282/292 on the summit for advertised. Cranes HP series appears to be the same as summit, only problems is the summit cam card should be at .006, and the crane at .004. I don’t put much stock in either rating being right. The summit and the HP series cranes appear to be the same to me, probably ground by one of the big cam companies. The HMV is right below the hp series in their cam profile list. If you compare the hp and the hmv in the crane catelog it is probably a decent comparison. FWIW

https://issuu.com/am_cranecams/docs/...rofile_catalog

[Stan Weiss]

Originally Posted by Jay S

If you have them talked into doing a 2500 stall that should take car of any lack of bottom end power the 2802 lacks.

In the mid 220s it has always seems like cam options are slightly limited for off the self stuff. The other cam similar to the 2802 is the crane 278/290 222/234 114lsa, .467/.469. Several members on here run it. It should have a little stronger bottom end power than the 2802, might even oust or come close to the 60916. Mainly because that crane is has less seat timing than the summit and is 5 degrees asymmetric, versus the summit and the crower are symmetric profiles.

The crower and summit cams the opening rates and closing rates are the same, versus the crane has 5 less degrees on the opening side versus the closing side. Plus the 278 rating is “suppose to be” at .004 tappet (I question some of their ratings since Harvey Crane left, some of their profiles look like .006 now). Not a big difference on the asymmetrics, but the 278 crane would have a little better vacuum and bottom end every bit as good of top end. I have done more engines with symmetrical cams, but the last several years we have been using asymmetric profiles and running bigger profiles on the higher compression stuff. Thought I would mention the 278 crane, for the lift, duration, wide lsa, and being asymmetric grind, it has a well designed cam. Bang for the buck, summit grind is great though. I would do the crane before the 60916 at 9.8.

Jay,
Are you going by listed spec or have you have you run them on a Cam DR?

When a cam is asymmetrical it can either have the opening shorter and longer closing or longer opening and shorter closing. From what I understand UltraDyne used to have a few extra degrees on the closing side.

Stan

[chiphead]

I ran the numbers thru wallace calculator. I assumed both were installed at 109 ICL. Not sure if the calculator can account for asymmetric profile.

2802 has IVC of 68* ABDC
Crane 278 has IVC of 70* ABDC

What I don't understand is how a Lunati HR 231/239/110 on a I06ICL has a similar IVC??

Lunati 231/239 HR has IVC of 67* ABDC

Does that mean the HR will have a similar dynamic compression, even though it has 7* more duration at .050"?

[Stan Weiss]

Originally Posted by chiphead

I ran the numbers thru wallace calculator. I assumed both were installed at 109 ICL. Not sure if the calculator can account for asymmetric profile.

2802 has IVC of 68* ABDC
Crane 278 has IVC of 70* ABDC

What I don't understand is how a Lunati HR 231/239/110 on a I06ICL has a similar IVC??

Lunati 231/239 HR has IVC of 67* ABDC

Does that mean the HR will have a similar dynamic compression, even though it has 7* more duration at .050"?

The first question one needed to answer is what is ICL? On a symmetrical cam this is not a problem. On a asymmetrical cam is ICL half way between opening and closing or the point of max lift? I use the method the cam manufactures say to on the cam card. Also when I calculate DCR I use seat_to_seat numbers and not 0.050" numbers.

Stan

[Jay S]

Right or wrong, I always use .009 at the valve for the IC for Wallace’s dynamic compression calculator. The .004 or .006 at the valve might be more accurate if every cam had the same lash ramp design with in the same series and in the OEM world. I simply do not use the ASAE SAE specs much. We try to check specs for cams out at the valve at .009 or check the .006 tappet and add the effect of the rocker arm ratio in. I use cam DR numbers, but also have checked cams and ran regression coefficients to take out the extremes on measurements. Compcams and Bullet I can pretty much use the published profile numbers. I prefer Bullet, you do not get the Corporate answers like the big companies. I haven’t done much with Cranes for a while, so the crane stuff is not as fresh in my mind as it use to be. At one time I had high and low dcr number recommendation for all the crane cams for a 400 cid engine. I wish I had it yet, the trends were interesting as the cams went bigger and switched to rollers.

It is exactly right that the lunati HR will have the similar dcr numbers, it doesn’t account for area under the curve, cam asymmetrical trends, or the E/I split on the head flow and cam. I just trend the DCR down or up on that stuff and adjust the overlap so the exh closing is not behind the intake closing on the overlap for the ICL depending on the E/I duration split.

Usually the asymmetric measurement or the pan is measured from .004 tappet to .050. By .010 tappet most cams are symmetrical. The lobes UD Harold designed seem to run around 8 on the pan. His past comments I have found to be true on his cam design and pan. The cranes hmv series are 5, comp XE if I recall correctly run about 6, magnums have pan to, but I do not recall how much, at least 5. I have never seen a crower having any pan, I have seen a lot of intentional design making the lash ramps gentler.

What does the pan matter? That pan changes the way the cylinders are filled. If your already pushing compression putting a cam in that is really good at filling cylinders is not helpful. You need to adjust the dcr down via the static or a bigger cam profile.

When your doing budget builds and using books cams sometimes have to work with the best match of off the self parts. In this case it looks like the 14cc dishes icons and the 2802 should be good choices.

[Will]

Was in a car club back in the early '00s and one of the members had a '67 'bird with a high compression 400 in it. #16 heads (unported) on a TRW forged piston bottom end. Nothing fancy. I think he had a Torker II intake with a Holley 800 on it, mild converter and 3.73s. Had the 2802 cam and that engine ran like a raped ape on the cheapest 92 octane he could find. Never had any problems with the engine.

[TransAm 474]

What AC Spark Plug should we run in this? Just want to make sure we get the heat range correct. Just as a reminder, these are 12 heads, big plug......

[Douglas Willinger]

How much compression ratio is feasible with iron heads, with somewhat higher octane fuel, not 91-93 with or without say 10% Ethanol, but say 95-97 octane, achievable with added octane booster.

Perhaps an intermediate blend of Petroleum and Ethanol, say, E-30, E40, E-45?

https://www.eesi.org/…/view/fact-she...ry-of-o…

"A national transition to an optimized mid-level ethanol blend, between E25 (25 percent ethanol, 75 percent gasoline) and E40 (40 percent ethanol), would lower consumer fuel costs and standardize the fuel supply. The Department of Energy recognizes that increasing the ethanol content of gasoline is a potential pathway to increasing the octane rating of the gasoline supply. A mid-level ethanol blend would enable the design of highly fuel-efficient engines that would significantly reduce petroleum consumption, reduce life-cycle greenhouse gas emissions, and help meet higher fuel economy standards. As of now, the Department of Energy and the EPA have approved the use of E15 for make and model year 2001 and newer vehicles, which account for 80 percent of the vehicles on the road today."

Also see:

https://www.frontiersin.org/articles...015.00016/full

"In addition to the octane number benefits of ethanol, several studies have indicated that complementary benefits to octane number can exist with intermediate ethanol–gasoline blends. Splitter and Szybist (Splitter and Szybist, 2014c) have shown that intermediate gasoline alcohol blends, like E30, have reduced combustion duration, and more recently Szybist and Splitter have shown improved dilution tolerance of similar E30 fuels over reference fuels and gasoline (Szybist and Splitter, 2016). Beyond flame speed and dilution tolerance effects, intermediate ethanol–gasoline blends have been shown to exhibit reduced combustion temperatures and increasing engine efficiency (Szybist et al., 2010; Jung et al., 2013b), which Szybist et al. illustrate could be a product of increased molar expansion ratio of alcohols compared to gasoline (Szybist et al., 2012). Many have indicated that the charge cooling of ethanol in direct injection engines offers reduced enrichment need (Stein et al., 2012, 2013; Jung et al., 2013a). An interesting recent study of Sluder et al. (2016) suggests that, in practice, fuel sensitivity – the fuel RON minus the fuel MON octane numbers – by default accounts for much of the charge cooling effects from direct fuel injection on fuel antiknock performance. Thus, these combined studies illustrate that the potential to increase engine performance and fuel economy offered through intermediate ethanol–gasoline blends extends beyond increased octane number alone

It was found the incremental increase in fuel ethanol content from E10 to E15 and E10 to E25 could enable fuel octane number to increase from 87 to 90 AKI and 92 to 95 AKI for regular and premium grades, respectively. Additionally, these finished fuels could be achieved by blending ethanol with base stock fuel octane numbers identical to those historically used for leaded fuels. Therefore, an incremental increase in fuel octane number from a 5 to 15% increase in fuel ethanol content could be a process that enables continued future evolutionary changes to personal mobility that comply with historically documented consumer technical and regulatory trajectories."

Notably, such mid range grades, E-25/E-45,would be adaptable to older design vehicles as those with carburetors, and hence offer a far greater spectrum of consumers.

[TransAm 474]

This build will come out around 9.8-1 compression..

1970 YZ block .030 over
4.150" bore
Zero Decked
Stock N crank 010/010
Eagle H-Beam 6.625 press fit rods
Icon IC891-030 pistons 14cc dish
Butler Total Seal classic rings 4.150" drop-in
Felpro 1016 .039" head gaskets
Stock 12 heads, cc'd at 70c chamber, hardened exhaust seats, Ferrea F5143/F5144 Stainless valves, Crower 68404 springs
9.8-1 compression
Summit 2802 Camshft
Stock 1.5 rockers
Hylift-Johnson 951 lifters from Paul K
ARP rocker studs and poly locks
Stock cast iron intake
R.A. III Qjet setup with Cliffs parts and recipe
Stock points distributor recieved
TH400 transmission
Hughes GM25-BOP converter
3.55 rear gears
1970 Trans Am
Pump Gas 91 Octane

What AC plug would be good to use in this application?

[Cliff R]

Combo looks fine.

I've seen two 400's go on the dyno with the 2802 cam (one was actually a 389) and apprx 10 to 1 compression with early big valve heads and mostly stock otherwise.

They made around 380-385hp and went into vehicles and fine on pump gas. We were directly involved with one of them as I knew the owner. He bought a 13" Continental torque converter from us for it and we installed it for him. I did the carb and distributor for it as well. Application was a full size car 66 or 67 Bonneville nearly as I can remember.

We kept in touch for years and the engine was fine, but I haven't heard from him in about 5 years or so, but I'm sure it's still out there getting it done as he's local here and would have contacted me if there were any issues.......Cliff

[unruhjonny]

Originally Posted by TransAm 474

What AC Spark Plug should we run in this? Just want to make sure we get the heat range correct. Just as a reminder, these are 12 heads, big plug......

the 100% correct one is an NLA R44S;
many here have had luck using the one step hotter R45S which is currently available.

I have had good experience with the Autolite 85;
The Autolite 85 seemed to run better than the R43S which is a cooler plug than OE.

[Cliff R]

I use and prefer NGK's, and have had perfect success with them to date. I will even use the same plugs over and over as I have in my own engine(s) for decades. I just periodically run them to the bead blaster and knock off all the carbon, check the gap and back in they go.

For several decades I ran the same set in a 400, then two 428's, then a 455. I only replaced them because they would fit the new KRE heads.......Cliff