Thread: newbie help building engine

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Originally Posted by 1gary

The point of the provided link I posted in summary is too big of a duration on a low compression engine makes it preform worst.The days of just sticking in a cam are long gone because we know so much more about cam timing,how that interacts with compression ratios,formulas about SCR's and how to use DCR's because of pump gas,how to use aluminum heads for a increase in SCR's,sizing intake runners for the c.i. of a engine,targeting a .045 quench and piston types to get there.

The cam quest will only give you answers in the point of view from cam use and there is a ton more to it than that.

On a budget less the $1,000.00, SCR, DCR, Aluminum heads, Runner size, quench, and all the other hi dollar engine building stuff doesn't even come into consideration!!!!! The OP wants to change cams, period. Not be made to feel like an idiot as usually happens when an engine newbie asks a simple question!!!!!!!!!!!!!!!!!!!!!!!!!!!

PS---For this and many applications, Cam Quest is a very accurate program on selecting a cam and components for an engine.... At least IMO it beats the heck out of studying all this online bs about engine building that is no more or less then someone else's opinion of how things should be!!! It's a whole different world just changing out a cam and lifters then building a one off race engine that every component is optimized for performance!!!!! The main difference is, the OP wanting to re-cam an engine on a tight budget is real world stuff, not some imaginative engine build that some spend months researching and most never actually even turn a wrench on building something!!!! This man's budget wouldn't began to cover the machine shop bill for a race engine!!!! I say more power to you, OP!!!! Build and do what you can afford to do now, there's lots of time to build some perfect to the nuts engine sometime in the future!!!! Just do it!!! That's what Hot Rodding is really all about!

How firm is the budget??. Any room for expansion??. One thing you learn quick is how these parts are only one part of a system(a cam) and although you thought you could make a simple change,it does involve a host of other things even for the simplest street rod.A grand should cover a cam and kit of less than a 500 lift,but even at that,relevant to the heads,valves,compression ratio,exhaust,intake carb,etc ends up leaving alot on the table.

It gets back to my post of what is your hp goals?. Then what can you afford to build given those goals??.

Certainly doesn't make much sense to tear down a block to deck it and not look at boring it with a new set of pistons that could positively effect quench and that is part of the puzzle to prevent pinging on pump gas.

You can and should plan a big picture build plan for even the simple cam swap.Projects should have no end date and maybe if you chose a cam that was one to be used with bolt on heads later.I mean plan ahead like what you said do it once. Seems to work if you find a cam your interested in,buy the one just below it.

Bull! I agree 100% with Dave. You want to change out your cam and lifters, not build a race engine, or plan to build one later. That fine article from the Crankshaft Coalition, (written with a lot of input from TechInspector1 who sometimes graces us with his input here and who knows more about cams and integrating them into any engine) provides excellent guidelines on choosing the right cam based on the engine you have. Don't let anyone belittle you about what you want to do or the amount you have budgeted. You don't need any master plan if all you want to do is swap a cam. You can use the information you have to get a modest HP increase, and also pick up a modest lope that will let everyone know you're not running a stock engine. Forget about horsepower goals, torque goals, and all the other high performance, high efficiency falderal. Dave very accurately pointed out that you're going to need to go into the engine and do some machine work to worry about such things, so pick out a cam that's not too wild for your compression ratio, have a ball, and ignore anyone who tells you you're wrong to buy a cam and lifters for an otherwise stock engine. Been done that way for many, many years, and you can always go bigger down the road, when you have the need, and maybe the extra bucks to play bigger. Have fun!!

Alright just so i know when filling out cam quest . Is that something to consider upgrading? Is the flat tappet hydraulic lifters just fine.

Originally Posted by mikesaik

Alright just so i know when filling out cam quest . Is that something to consider upgrading? Is the flat tappet hydraulic lifters just fine.

For me, I would not consider buying a flat tappet cam today given the changes in our motor oil configuration and the well documented history of cam failures due to problems on initial startup, or some later event that causes a tappet to stop rotating in the bore. You cannot know that the problem has started until the symptoms of a flat lobe appear, and by then you have metal particles carried through the engine and you're facing a total teardown to clean it up. Some say once the break in is done right they're OK, but roller lifters are the only way to go, IMO. Others may have other ideas.

Flat tappet hydro lifters is what you have and would need to buy a fresh set to go on a new cam.You can't reuse the old ones on a new cam.Hydro roller lifters is a upgrade,but a expensive one.It is a hydro lifter cam and roller lifter set and it's advantage is they have a better cam profile and don't need special attention for a cam break-in as a flat tappet cam does.

What Roger post states is correct and the warnings about flat tappet hydro cams.With a grand you should be able to cover the costs of a upgrade hydro roller cam as apposed to a cam and kit flat tappet cam where the costs would be about a third of that.

Mike,
My comments so far in trying to help you is to try to get you to plan now for future mods so when they come to past,you don't have to spend this money all over again having to replace this cam and kit.So I am trying really to save you money.As far as your budget and how much you would consider spending,it is a way to see if we could squeak out some more mods given a bigger dollar amount.Again in a effort to get the biggest bang for your buck.The way to do that is independently learn as much as you can on how these mods interact with each other and as your doing ask questions.

Originally Posted by mikesaik

Alright just so i know when filling out cam quest . Is that something to consider upgrading? Is the flat tappet hydraulic lifters just fine.

They still work fine, but you have to pay very close attention to the Manufacturer's recommendations when it comes to cam installation and break in. You will also need to use the correct oil, Joe Gibbs oil and a few others are the ONLY ones on the market with enough ZDDP to keep the cam from wiping out the lobes!!!! The biggest cost of the conversion to hydraulic rollers is the lifters themselves, I have seen them for sale used on Racing Junk and other sites... You can save some money buying used, just always the chance the guy selling them is a less-then-credible seller and pedaling some worn out junk!!!!!

let me start by saying i'm taken back by how quick you guys respond. I love the support and with every reply i'm feeling more confident about cams. To answer the budget question he was only looking to spend around $300-$500 bucks, however if it comes down to it that i'd be cutting a corner just cause of the budget then i'll be willing to through in some of my own money just to get it right.If thats the case then i'd would be willing to have a maximum budget for a $1000. I like the thought of hydraulic roller lifters over the original style. Does changing the lifters to rollers affect valve height more or is that all compensated into the cam i would be buying. I'm going to try that cam quest now but ill use the option of hydraulic roller lifters and see what comes up. Keep it under .5 lift right? If i go over that creates more bills right?

By valve height, are you referring to the pushrod length that would be required or???? I've been well pleased with the results from Cam Quest, used it for cam selection on a number of cars. Don't let the budget deal worry you, all of us have worked under the same constraints before, too!!!!! Some folks will try to tell you that you can't "just" change cams, and if you're trying to optimize the performance of any engine you're building that is true..... But when the real world of a $$$$$$ limitation sets in, then concessions have to be made. Hot Rodding for me has always been about making the most out of what you can afford, and as I posted earlier, don't become discouraged by the "experts" who try to tell you that you can't do things this way.......If we all had to wait to do anything til our budget was unlimited, nothing much would ever get done!!!!!

I mean valve height by what the cam has labeled as valve lift using std rockers. For example i did the cam quest for hydraulic roller lifters and received about ten results. Although only one had valve lift less than .5 Heres the details.

Comp cam grind number x4280hr
duration at .050 Intake 230.00 Exhaust 234.00
Valve lift Intake .474 Exhaust .474
lobe centerline is 111 Is that also referred to as lobe separation angle?
Intake centerline is 107

Well, with hydraulic rollers the cam can have a lot faster ramps, and therefore more lift......However, with you heads coil bind can become an issue--too much valve lift with not enough spring height can cause the windings on the valve spring to contact each other at full lift.... This is something that should always be checked when changing cams.... I believe I would follow up the Cam Quest suggestions with a call to the Tech Department at Comp Cams before ordering, too. I always do that, and have gathered a ton of information from them to help with performance!!!!! They're in the camshaft business to make a living, and the better help, advice, and assistance they can give you as a customer is only going to help their business!!!!

I mentioned to keep lift under .5 because of your budget.

To go over .5 means pinning the rocker studs, new springs, and potential for lot$ of problems such as bent push rods, bent valves, and poor power. The engine might sound like a beast at idle, but would be a complete dog, and not a scalded dog either.

I don't believe anyone else touched on exhaust mods. Long tube headders would compliment a mild cam nicely, and are one of the cheapest power mods you can bolt on, even provide fuel economy improvement in most cases.