Well, my .030 over 318 has decks from .095-.105. Both sides. Original plan changed, said eff it, squared to 9.58 vs 9.6 spec. So 9.58 and square yields 8.25:1 SCR vs the variances around 8:1 SCR. Is it even worth it? I’m sending the cam out to see what was put in it many years ago. But now leaning on just taking the rotating assembly in for balancing, figure out the cam, little head grinding and put it back together.
Since you already have done the block machine work, just complete the build. It will run fine on crappy regular. 318 are quite reliable, they certainly made them for a long time. Use what you have.
I bet you're going to be happy enough. A good increase in airflow with a nice intake and carburetor, good flowing exhaust, heads and a cam meant to work well with relatively low compression/low rpm will wake it up.
The engine doesn't care about static compression ratio , only cylinder pressure. One component can make or break that engine! [The Camshaft] Try and get a cam cut with the highest lift possible but minimal duration and overlap. Avoid the trap of having too much LSA because the engine won't breathe enough to benefit from this. The short timing overlap prevents the engine bleeding off too much cylinder pressure. AND it makes a nicer driver
Yes, you told me that before. I should have just moved on it, but have gone down the camshaft rabbit hole. Pretty much just should have taken what you said and called a grinder. Hard headed Italian here!
Depending on the cam you’re going to have checked out, I think you will have what you want without any more machine work. Estimating a 4% HP gain per point of compression and assuming your engine will make 250 HP in its current state. You gain 1.5 HP going from 8.1 to 8.25 to 1, if you increased compression to 9.1 you would gain 10 HP. One of the best cams for a low compression 318 is the Hughes 318 Whiplash, this cam takes advantage of the .904 lifter. It is expensive and you have to use their lifter, springs and oil to get their No flat cam guarantee. $292 for the cam and $635 for the cam, lifter, springs + oil. The specs are : 109LSA +5 installed at 104 Valve lift with 1.5 rockers .480 in .526 ex Duration at 0.050 213 intake 226 exhaust Designed for 8.6:1 or less compression, stock or low stall converter and 3:55 gears or less. Has a very lumpy idle and about 9 - 11 inches of vacuum at idle. This is one of the cams I’m considering. Dan
With that compression ratio, I would look at a little cheater blower or other forced induction apparatus to get the HP numbers up.
You know, I wonder if this has been discussed before? https://www.bing.com/search?form=MOZLBR&pc=MOZR&q=how+to+hot+rod+your+318 https://www.google.com/search?q=Performance+from+your+318 https://www.ecosia.org/search?method=index&q=hop+up+318+engine
Best bang for the buck is a stroker kit. Figure 2K. Add in a gasket set, a cam kit and used intake/carb. Probably under 3K if you can find bargains. Problem is, that may be double your budget or more and doesn't include any machine work. So if you are trying to keep it under 1k, it might be done, but requires just a gasket set, cam, maybe rings and bearings and no machining, just DIY hone and lapping. This is the make or break point. Another long block out of your local yard that doesn't need stuff is going to be under 400. If your current block and heads need more than that in machining, AND you can find another that just needs hone and lapping, you are ahead. But it's going to be almost half your budget! Just get the best 360 out of the yard you can find and drop it in. U PIK IT - V8 ENGINE W/O ACC 295.00 Each 55.00 Core
I understand wanting to do more with less, but if budget is the limiting factor, you go to the yard, find as many 360s as you can, pull the heads and inspect, grab the one that needs little to no work and put it back together with gaskets and aerosol overhaul it. Try to find the lowest mileage little old lady/man car. It will take more money to fix what you have. parts and prices are Rock Auto. FEL-PRO FS8553PT12 gasket OH set is 85 bucks SEALED POWER 5024MA main bearings are 78 bucks ENGINETECH BB136J rod bearings are 15 bucks a pair 120 bucks. You haven't touched the valvetrain or pistons/rings yet.
I get ya Rod. Thing is this engine went to a shop some 25 years ago and rebuilt. All I recall about the cam in it was “like an RV cam”. Card is long gone. I’m just looking for the best bang for the buck with what I have, I don’t need/want 300 HP, etc. The truck it’s in is 2525lbs (before I crawl into it). So what originally started off with getting around 9-1 SCR, went to just squared and 9.58 deck height to just leave it as is and focus on the cam. Based on what @Kerrynzl has said, my cam may or may not (I’m leaning towards not) be optimized for the low compression I’m running, but truly don’t know. I figure at this time I can send the cam out for measurements, or just look for a cam as Kerry suggests and eliminate one step, trips to the machine shop, etc.
Mike , The big question is "How are you going to drive it?" Cams are easily swapped out. Buy a multi-keyway timing set and degree your existing cam using the compression test method Doing this can save buying another cam and lifters especially if it is “like an RV cam” You can get surprisingly good results from being ruthless with your decisions. If you don't overspend on this build ,your options are open later. [including a swap] read this hotrod.com/articles/mopp-0312-318-long-block-bolt-ons/
Seems to me I have read this conversation on this board, or a different board concerning this very motor before, not very long ago. Apparently the last time, when he received the same answers, they were not what he wanted to hear. So, call a cam manufacturer give them your information, tell them what you want, send them your money, do what they tell you, put the stuff in your 318, then complain about how it isn't what you wanted. Or you can sell me the long block 318 you have and put that money towards building the motor you really want. PM me your walk away price!
I had a different agenda before Gene, I’ve scaled that way back. This question isn’t relative to the previous one.
You advance or retard the cam and keep doing compression tests for each setting You generally want as much cranking cylinder pressure as possible. If the cylinder pressure starts dropping off , you have dialed it too far. [either way] It is best to do this with a squirt of oil down the bore [to eliminate leak down]
I was just able to read the article. Certainly a significant improvement. And easily doable. Thanks again, we need double likes on meassages
That's what I figured, thanks. Not sure if I'll be able to do that on a fresh build, engine on stand, but maybe I'll figure something out.
Mike , you have the most realistic expectations for your engine. It is very easy for us to spend your $$ with good intentions. 230hp would be easy to achieve from a 318. I could get that from a stock 2 barrel with a bit of labour. But using the cam you already have [or maybe a better one later on] a 4 barrel and headers will push it over the line. [and a lot cheaper than blueprinting] By the time you read this, it will be Xmas in NZ So merry Xmas too you and all the HAMB members who read this
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