Lets discuss another engine build

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If mine I'd use KB362, 0 deck to quench pad. .040" gasket, XE268H and have a great engine.

I would also do a few oiling modifications before block goes to machinist.
 
rumblefish360 said:
The amount of deck milling needed or not. The pistons will not sit at zero deck out of the box. Or they shouldn't. If the pistons are .010 in the hole, thats fine. You need to calculate the ratio. In order to do this, the piston to deck clearance must be known as well as cylinder head cc amount and the gasket dimensions.

These pistons at zero deck with a 72cc head and a .039 gasket will yield a 9,8-1 ratio. There is a slight variable with the cylinder heads gasket bore. So you could gain or loose .01 or .02.
If you use a thicker gasket, lets say .055, the ratio drops a bit closer to the 9.5-1. So IF your piston is in the hole .010 or .020, that is OK and actually probably a good thing. 9.5-1 is pushing matters with that small cam. And I do mean pushing it. Your better off @ 9.0-1.

Through usage, the carbon build up will add a little more compression. Though it will take a long time. It does slowly add up. So if 9.5-1 is border line, what will another .03 do? Answer, nothing good.
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Ok, that makes sense to me. One thing and not sure if you caught it, is that I have 64cc heads on average. Which obviously bumps the ratio up higher. Now if Im thinking of this correctly that means I should go with one of the original two pistons, so that Im not above that desired 9.5 and probably closer to the 9.1 side of things. To allow for the carbon build up and gaskets etc... Correct?
 
nm9stheham said:
As for the KB362's, I just added up the numbers and the compression height is 9.558 which is about .041-.042" below stock LA deck height and about .02-.025 below stock Magnum deck height. The H116CP's are more like .055" below stock LA deck and about .035-.040 below stock Magnum deck. DO you have a Magnum block?

So either will need a lot of decking with an LA block if you want to get to zero deck and have a quench gap. The Magnum decking to zero deck would not be so bad with the KB's. Conventional wisdom is that you run a true 9.5:1 CR with iron heads IF you have a quench gap, otherwise keep it down closer to 9:1. With the 262 cam, I would stick with these rules.

I too am getting 9.8:1 SCR with the H116CP pistons with a .051" thick head gasket and assuming a Magnum block, but not zero decked. With the H116CP's at zero deck, I get 10.3 SCR with a .051 head gasket. Either is too high for your street use with pump gas and iron heads and no quench per conventional wisdom.

Going back to the KB's I get 9.25:1 with the KB362's at zero deck and a .039 head gasket (Felpro 1008) and a Magnum block. IIRC, the raised pad on the valve side of the KB pistons is at the top and will form a quench gap with the head's closed area, and so you will have the benefit of a quench gap to help the pump gas be OK with a 9.25 SCR. But check with KB on that raised part to be sure....) Those pistons are pretty much designed to meet your application. That is one thing I have noticed with KB: they seem to have more variety of pistons and look to have done their homework in dome designs to meet both the wilder high CR drag race apps and the pump gas street engines.

And as far as hypers... I have raced hypers a fair while with 14-15 psi boost with no problems; I was a bit worried but they were fine. And we just put some KB hypers into my son's 340 with the tops shaved .030"; the thinnest part of the head is donw to .185" miniumum thickness...so far so good but we yet to have really let 'er rip as we progress through a gradual break-in and wringing out fo small problems.

But with the lighter weight of the KB 362 hypers and pins, you will need to re-balance the engine, as you are dropping about 122 grams per piston and pin. It will make the stresses on the engine less. The H116CP weights are almost identical to stock so no re-balance is needed for those.
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Im running a LA block, Magnum heads.

I was basing all my ratio numbers off of a .040 x 4.080 head gasket and 64cc head chamber. I wasnt sure where to start so I picked that gasket which I believe was a Felpro.

I am ok with re-balancing the rotating assembly. Im pretty much looking at it like a brand new engine build so what ever I have to do to make it right.
 
I've been following this post and I do however have a question. I was always under the impression that the xe268 comp cam was doggy on a 9:1 compression ratio. Now you guys are saying that it's too small? I've got just over 9:1 and I went with the HE268 to be conservative. So is that cam waaaay too small? I've got 596 heads with 2.02 valves, I can tell the upper rpm lacks but I also contribute that to the performer intake. Plans are for an RPM or an air gap. So what cam should I be using at a 9.5:1 ratio? The car has 3.23 gears and a 3 speed manual. It seemed to pull fine til it reached 5k rpm then died out. I always ran 91 octane and didn't notice any pinging.
 
Coronet 500 said:
If mine I'd use KB362, 0 deck to quench pad. .040" gasket, XE268H and have a great engine.

I would also do a few oiling modifications before block goes to machinist.
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By oiling mods, I assume you mean clean up the block so that oil can drain back easier? Or was there something else you had in mind?
 
straightlinespeed said:
By oiling mods, I assume you mean clean up the block so that oil can drain back easier? Or was there something else you had in mind?
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Oiling mods as in drilling out the oil passages in the block so they are not blocked by casting flaws and whatnot. There is a sticky somewhere around here.
 
nm9stheham, I do believe what your saying. But the difference in a race engine vs. a street driven small cammed engine are two different animals not to be compared.

Straightline, didn't know your chambers are 64cc. I also possibly assumed they are a iron head, which would be where I would get the 9.5-1 ratio. Add 1 full point for aluminum.
I gave you my advice on what I think is a wise & safe course. But if you want to push it, then have at it. It is something that I'm doing right now and something I know I can correct if I push it to far.

Alpha13, in general, a cam should be treated to the compression ratio that has it working at its best. When is the ratio to low or high. When the engine doesn't run. Where is the perfect ratio for the cam? The manufacture has guidelines that should be looked at and followed. Though it should be understood that each manufacturers guideline maybe a different thought in there head.

Compare CompCams descriptions with CraneCams descriptions and note there very different for the similar cam by the other. You would think one is nuts. If you have never read Cranes suggestions, they list compression ratios and cruise speeds a good bit higher than Comp does. Now go compare it the other cam companies

I'll save you some time for the lesson and say there is a large operating window in which a cam will perform really well in. You just have to remember that your octane limited. The cams description of peppy vs. doggie can be a issue of splitting hairs or a serious performance gap.

nm9stheham's testimony is I'm sure 100% accurate for his vehicle. He keeps mentioning it as proof. However his race engine is a different animal and so is his cam. While someone, anyone here will say an engine is an engine and they respond the same, I say true to a point.

I still stand behind what I said about how much or little you will feel or not. My butt dyno doesn't have a huge memory storage as to keep excellent track of what one piston change feels like compared to the next. LMAO, I don't change pistons that often.

I just find feeling a 4.5% change in power which I showed the above calculations to be something I would feel much less whoop and holla about. Which leaves me with this question for everybody, not that it has to be answered by anybody.

How much of a victory margin will be shown at the end of the 1/4 mile strip with an additional 20HP? Let's just use 2 identical '70 Dusters for the example with the one exception of the compression ratio of one of the cars being 1.5 down on ratio on the posters intended XE268 cam.
 
rumblefish360 said:
nm9stheham, I do believe what your saying. But the difference in a race engine vs. a street driven small cammed engine are two different animals not to be compared.

Straightline, didn't know your chambers are 64cc. I also possibly assumed they are a iron head, which would be where I would get the 9.5-1 ratio. Add 1 full point for aluminum.
I gave you my advice on what I think is a wise & safe course. But if you want to push it, then have at it. It is something that I'm doing right now and something I know I can correct if I push it to far.

Alpha13, in general, a cam should be treated to the compression ratio that has it working at its best. When is the ratio to low or high. When the engine doesn't run. Where is the perfect ratio for the cam? The manufacture has guidelines that should be looked at and followed. Though it should be understood that each manufacturers guideline maybe a different thought in there head.

Compare CompCams descriptions with CraneCams descriptions and note there very different for the similar cam by the other. You would think one is nuts. If you have never read Cranes suggestions, they list compression ratios and cruise speeds a good bit higher than Comp does. Now go compare it the other cam companies

I'll save you some time for the lesson and say there is a large operating window in which a cam will perform really well in. You just have to remember that your octane limited. The cams description of peppy vs. doggie can be a issue of splitting hairs or a serious performance gap.

nm9stheham's testimony is I'm sure 100% accurate for his vehicle. He keeps mentioning it as proof. However his race engine is a different animal and so is his cam. While someone, anyone here will say an engine is an engine and they respond the same, I say true to a point.

I still stand behind what I said about how much or little you will feel or not. My butt dyno doesn't have a huge memory storage as to keep excellent track of what one piston change feels like compared to the next. LMAO, I don't change pistons that often.

I just find feeling a 4.5% change in power which I showed the above calculations to be something I would feel much less whoop and holla about. Which leaves me with this question for everybody, not that it has to be answered by anybody.

How much of a victory margin will be shown at the end of the 1/4 mile strip with an additional 20HP? Let's just use 2 identical '70 Dusters for the example with the one exception of the compression ratio of one of the cars being 1.5 down on ratio on the posters intended XE268 cam.
Click to expand...

Well I would feel that it would depend on several factors including but not limited to, if the two cars hooked exactly the same, the reaction time, the wind speed and direction between runs,... But even then I would guess it would only be a foot or less.
 
I can throw out a recommendation for a cam, but without everything else in the mix, such as static compression ratio, what pistons you will run, how much quench, if any and so on, it will be as good of a recommendation as a five year old can give.
 
If I was building a cruiser,This is what I would do; It's a theory;
With closed chamber,iron heads,I would pump the Scr to the moon, or at least to whatever it takes to make a DCR of 8.0 to 8.5 . On a 4.03 x 3.58 this would be 10.0Scr +/- .25.
Detonation is only a concern when the chambers see full atmospheric pressure/density. Any time the engine is throttled and and the chambers are not seeing full density,the more Scr the better.This makes a more efficient engine and translates to snappy performance and better mpgs.
There is just one caveat; If in fact the Scr is too high for WOT running,then the chambers must never see full atmospheric density and full ignition timing at the same time.On a cruiser,I see that as doable tune.
I would also employ the "Tight-Quench" theory. And, instead of decking the block down for short cd pistons, I might get pistons that are tall enough to be machined down. Any extra money spent on this will quickly be paid back at the gas pumps.I would set it up using the thin .028 headgaskets.I would put a very small Vacuum sec 4bbl on it, with fresh cold air. Then I would Tune the heck out of it.
That's what I would do. This is an opinion.

Now here's a fact;
I built an engine very much like that, except with aluminum heads, and 10.8Scr. The cam was a 223/230 Hughes(HE2430). It accepted full timing,(32 to 36 degrees), and burned nothing but 87E10. The pistons were KB107s at zero deck. The gaskets were the .028s.(yes that means I was running .028 quench).The gaskets gave up at the end of the 2nd year, and I replaced them with .039s (now running .034quench).At this time I remachined the decks to bring the pistons out of the hole .005. The Scr dropped to 10.7. I ran a 750DP on the AG,with fresh cold air.
Ok, so I have aluminum heads, that work at 10.7/8.8,on 87E10. And I believe the Scr could go higher from the results posted here on FABO in the past.How does that apply to you?

Here's an opinion;
If I was to build an engine with closed chamber,iron heads, as in the opening statement(Scr of 10.0,etc); I believe it would work just fine,as a cruiser.And I'm willing to bet it'll take WOT as well.And I think it would run harder than my beast did.
But if you even think that you wanna run it hard, more than occasionally,(remember I tuned mine to 87), then I suppose if you dropped the Scr to 9.5 or 9.0, I suppose it would be a set-it and forget-it type of deal. (The .039 gaskets would get your Scr down to 9.66). But that is not what I would do for a cruiser.

BTW; That combo of mine was very nice; enough power to go 106@ 3800ish pounds, and with a smaller,cruiser carb,a 600 vacuum secondary, I was able to tune it to get 32mpgUS,@4000lbs(with passenger and gear) with double overdrive. The final-drive ratio was 2.02. Rpm was about 1650@65mph. These are facts.
 
straightlinespeed said:
Im running a LA block, Magnum heads.

I was basing all my ratio numbers off of a .040 x 4.080 head gasket and 64cc head chamber. I wasnt sure where to start so I picked that gasket which I believe was a Felpro.

I am ok with re-balancing the rotating assembly. Im pretty much looking at it like a brand new engine build so what ever I have to do to make it right.
Click to expand...
OK, yes that is the Felpro 1008 head gasket.... .039" thick. The bore hole size is more like 4.12" or 4.18" but it has little effect on the CR. If you want the hole size to be very close to the bore size, then I only know of Cometic to do that.....at $200 per pair versus $80 per pair of the Felpro 1008's. But .028" head gaskets will reduce the decking cut and just put the pistons a bit down in the hole.

So the LA block will need more decking than the Magnum block; the KB362's will need less decking than the HC116P's. The intake will need milling too.

With the LA block and Magnum heads, you are planning on the AMC lifters and pushrods with the oil feed holes, correct?

I personally think the quench gap is worth the effort. .035" is the recommended minimum (depends on how it is checked) and IMHO, .040" to .045" is still good.

If you are re-balancing, and want to upgrade rods, then the SCAT I-beam's are worth looking into IMO. The great thing is that they are already weight matched at both the big end and pin end, as well as overall, and the weights are marked right on the box, so they are ready to go for balancing without any rod work, which saves $$. And the KB's we recently got were all within +/- 1 gram as were the pins, so along with the SCAT rods, you have piston/pin/rod assemblies that don't need any further balance machining. We just worked up our new bobweight (which anyone who can weigh a few parts to 1 gram accuracy or less, and can manage arithmetic, can do), and handed that and the crank to the machinist for a $95 balance job of just the crank. (For a 360, add in the flexplate and the damper.)

The Scat rods save a bunch more weight over the stock rods, like about 155-160 grams per rod, so your rod/piston/pin weight will be 275-280 grams lighter than stock (with the KB's), which gets more weight and stress off the crank, and helps revving (a bit).

But the Scat rods is just another option..... I am not trying to push you into it.
 
Sorry guys, I'm not ignoring this thread right now, but I'm out of town and only checking it from my phone. When I get a normal computer again I'll pipe back in.
 
Getting back to the tight quench theory.
When I was running that combo with the .028 quench,and the 223/230/110 cam, I just cannot express how pleased I was with that combo. If that cam had not dropped lobes, during the phase out of the Zinc stuff, I would never have needed more. That engine pulled right off idle and went to 7000 with the longest smoothest flattest power delivery I had ever experienced with a SBM. And it pulled double O/D with 2.9s. If you do the math on that I think it's about 1350@65mph, and, now this is important, it did so with the throttles barely open. That was a very sweet engine.
I still have that old girl, now with 125,000miles on her, but the cam was changed to a 230/237/110, and the quench, as mentioned was opened up to .034. This current combo is no slouch either, and I would highly recommend the combo to most street guys, but I sure noticed the shift in the power delivery. I wanna say I liked the 223 cam better, because of the sub 4000 character, but I sure do love the 4000 up character of this 230 cam.As a streeter,I did not like the 292/508/108 cuz the pull was all at the top.They say that cam is 249ish@050, but it only measured 240 in my combo.I imagine it would be a great strip or street/strip cam.
If I could offer any thing from my experience it would be this; street 360cams might fall somewhere between 220 and 240 degrees, with the lower being very cruiser friendly, and the upper end being strip friendly. And that's why I have a middle of the road 230* cam.
 
Ok, Im finally back to civilization and have my computer.

Thank you again everyone for the input. After reading thru everything I do want to play it safe as Rumble (Rob) said.

AJ, I appreciate the input, but for this engine Im going to keep the ratio below the 9.5. I do have another block that someday I will play with a more radical combo.

nm9, Thanks for the input on those rods. I found those on Summit Racing and I marked them. Depending on how much the machining bill comes in at will determine the extra funds I have to play with. Also yes, Im using the oiling lifters and push rods and have the oil galley's plugged to the heads.

After all the reading Im leaning towards the KB362's. I think the engine will be a very pleasant upgrade from what it currently is and I shouldnt have to worry about an octane issue or WOT ping.
 
Just double checking with all of you. The engine goes to the machine shop on Monday. I just want to know if there is anything else I should bring to his attention or even ask him about before he starts.
 
Run the KB 2 valve relief piston. Zero deck height it. Run a cam that can actually DO something instead of that cookie cutter 268 CRAP. You will need more cam anyway because the compression will be up where you have wanted it the whole time (which is really a waste) but if you're gonna do it you might as well DO IT.

I would recommend something in a solid flat tappet between 240-250 @ .050 on a 108.
 
I don't know people tie themselves to a certain compression when building a motor pick your cam and fuel and run the pistons gaskets chambers etc.. that give you the CR for that DCR.
 
RustyRatRod said:
Run the KB 2 valve relief piston. Zero deck height it. Run a cam that can actually DO something instead of that cookie cutter 268 CRAP. You will need more cam anyway because the compression will be up where you have wanted it the whole time (which is really a waste) but if you're gonna do it you might as well DO IT.

I would recommend something in a solid flat tappet between 240-250 @ .050 on a 108.
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Thank you Rob for the input. Given you know the history of my engine prior to the tear down. You remember all the problems I've had with it. Even after we went thru all the work last spring it was still a dog and never ran right. Why, no idea, but it could had been many things or just one thing. Since I did get the original engine shop to hook me up with what I originally asked for, I was going to make use of them. Which is why I threw out the KB pistons and one similar.

Your absolutely right, I have the option to build it the right way, which is what Im trying to do now. I know you have mentioned many times to me that I could have a good running engine on stock compression. Trust me I heard you my friend, which is part why I started this thread. I would like to know options I have and how to go about building a engine that Im looking for (good cruiser that can be fun).

If you have a suggestion on a complete engine build (using my same Iron Magnum heads), sorry I have to run hydraulic lifters and cam with that head, I think?!?! I would love to hear it. Even if using the same stock pistons, that I have now. Break it down for me, Im curious. You know Im not looking for a radical engine I just dont want a "factory" engine.

273 said:
I don't know people tie themselves to a certain compression when building a motor pick your cam and fuel and run the pistons gaskets chambers etc.. that give you the CR for that DCR.
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Well, partly because Im not a engine guru. I dont understand how to go about building a engine, hence why I asked. I can say it, I dont know jack about this subject. I dont know how to pick a cam, I've read articles on them but none of that makes sense to me.

I read threads where people want big horse power small blocks. I see them throw out SCR of 10.5, 11 and 12. I look at those numbers and builds know they have to run race gas. I know what I want and its not a big horse power engine. Just a good cruising engine, that I can have fun with, but not a factory built engine. Something with pep.

Really what I do know is that I have to be under 9.5 SCR with iron heads to run pump gas. I assumed that the closer I got to that number the better the engine will be. Sorry that was long winded but that is why I picked a SCR # I thought I had to have that info in mind.
 
RustyRatRod said:
I would recommend something in a solid flat tappet between 240-250 @ .050 on a 108.
Click to expand...
This does not strike me as what goes into a 'good cruiser'. It is getting into street/strip... IMHO. TC stall will have to be pushing 3000 RPM...revs can go to about 7k.... A 3k-7k RPM range is a smaller RPM ratio than a 2k-6k engine..... A wide operating range with a wider torque band makes a car easier to drive for general street use. (I raced a 4k to 8k 4 banger engine for quite a while, so I do kinda know that end of the spectrum.) Not trying to be disrespectful at all; the solid just does not seem to me to fit the desired application.

As for the solid AMC lifter to oil... look at the Comp Cams 801-16. That looks to be what would do that. There may be other brands.

The DCR first then SCR makes a lot of sense.... I actually start with an SCR and cam, get the DCR, and then adjust the cam or SCR a bit if needed to maintain the desired DCR limit. It just is that for a typical hydraulic flat tappet street cruiser cam, like the 268ish type, the SCR ends up at around 9.5 for pump gas and iron heads, for the pump gas DCR limit of the low 8 range. The 268ish hydraulic flat tappet gets set by the RPM range and stall.... like discussed above. It may be boring to do the same thing.... but there is clear rationale behind it.
 
straightlinespeed said:
Well, partly because Im not a engine guru. I dont understand how to go about building a engine, hence why I asked. I can say it, I dont know jack about this subject. I dont know how to pick a cam, I've read articles on them but none of that makes sense to me.

I read threads where people want big horse power small blocks. I see them throw out SCR of 10.5, 11 and 12. I look at those numbers and builds know they have to run race gas. I know what I want and its not a big horse power engine. Just a good cruising engine, that I can have fun with, but not a factory built engine. Something with pep.

Really what I do know is that I have to be under 9.5 SCR with iron heads to run pump gas. I assumed that the closer I got to that number the better the engine will be. Sorry that was long winded but that is why I picked a SCR # I thought I had to have that info in mind.
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That's fair, I see why you'd pick that cam it's about big as you can go before you starting to need deep gears and high stall and above that you start giving up bottom end for top end power.

Compression is important and the more you have the better but the problem is our crappy gas pushing it isn't really gonna gain you anything except headache if you get it wrong.

Theres DCR calculators online plug in you specs and figure what CR is need and I'd caution on the low side. Probably what they consider it pushing it for mid grade in your area "weather".
A few percentage of a point isn't gonna make that big of difference. And to push the limits everything has to be spot on from machining to tune to engine and air Temps to weather.
 
I have a blueprinted 11.5 : 1 static 360 with iron heads, running street and strip on 93 octane for the past 20 years. there are many factors involved - vehicle weight, rear gear, quench, running temp., cam, air/fuel ratio, timing etc. saying 9.5 : 1 is the max shows a lack of real world experience.
 
nm9stheham said:
This does not strike me as what goes into a 'good cruiser'. It is getting into street/strip... IMHO. TC stall will have to be pushing 3000 RPM...revs can go to about 7k.... A 3k-7k RPM range is a smaller RPM ratio than a 2k-6k engine..... A wide operating range with a wider torque band makes a car easier to drive for general street use. (I raced a 4k to 8k 4 banger engine for quite a while, so I do kinda know that end of the spectrum.) Not trying to be disrespectful at all; the solid just does not seem to me to fit the desired application.

As for the solid AMC lifter to oil... look at the Comp Cams 801-16. That looks to be what would do that. There may be other brands.

The DCR first then SCR makes a lot of sense.... I actually start with an SCR and cam, get the DCR, and then adjust the cam or SCR a bit if needed to maintain the desired DCR limit. It just is that for a typical hydraulic flat tappet street cruiser cam, like the 268ish type, the SCR ends up at around 9.5 for pump gas and iron heads, for the pump gas DCR limit of the low 8 range. The 268ish hydraulic flat tappet gets set by the RPM range and stall.... like discussed above. It may be boring to do the same thing.... but there is clear rationale behind it.
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The torque converter is one thing I didnt think about. I would rather not have to buy a new converter. Im running a Edge Racing Converter at 2800 stall. The rear gear ratio is 3:23, which I swapped to from 3:73. I still have the 3:73 gears so I could easily swap back, if needed.

I looked up those lifters, those will oil thru push rods? Also if I went with solid lifters then I would need adjustable rockers correct? Im currently using hydraulic lifters and magnum pushrods with the factory 1.6 ratio magnum rocker arms.

Back to the converter Im not sure if that has a lot to do with the engine build but thought I would bring it up.
 
273 said:
That's fair, I see why you'd pick that cam it's about big as you can go before you starting to need deep gears and high stall and above that you start giving up bottom end for top end power.

Compression is important and the more you have the better but the problem is our crappy gas pushing it isn't really gonna gain you anything except headache if you get it wrong.

Theres DCR calculators online plug in you specs and figure what CR is need and I'd caution on the low side. Probably what they consider it pushing it for mid grade in your area "weather".
A few percentage of a point isn't gonna make that big of difference. And to push the limits everything has to be spot on from machining to tune to engine and air Temps to weather.
Click to expand...

Thanks I'll look for the DCR calculators and start playing with them. Problem is I have no idea what DCR I should go for.

Marcohotrod said:
I have a blueprinted 11.5 : 1 static 360 with iron heads, running street and strip on 93 octane for the past 20 years. there are many factors involved - vehicle weight, rear gear, quench, running temp., cam, air/fuel ratio, timing etc. saying 9.5 : 1 is the max shows a lack of real world experience.
Click to expand...


I appreciate the input, but that is much to radical for what Im wanting in my car. Knowing my luck something would be just right and I dont want to risk it.
 
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