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First time engine builder (342?)

3K views 39 replies 13 participants last post by  Ed Curtis 
#1 ·
I've decided to try building a budget stroker. I've sourced a bare block. Visually looks good. Cross hatching still in cylinders with no visible scoring and no lip at the top of the bores. Did some measuring on it this evening and my worst measurements were (basing off 4.000") 0.0015" taper and 0.001" out-of-round. Deck flatness was within 0.0025" with the worst being inline with the cylinders on the edge closest to the lifters. I was planning on a 347 stroker but after my measurements I think I'm ok with just a hone and standard bore 342?

My plan is for this to be a fun learning experience and not go crazy just yet. So unless I'm mistaken my next course of action is to source the rotating assembly and main bearings, then clearance the block. I've looked at Eagle and DSS so far. Any other recommendations? This is going to take me a while since I'm doing it with my "play money" so this thread could go on for a while with me asking questions. Thanks for getting me started.
 
#2 ·
Cast crank, I beam rod? If so use scat, this will give you the best chance of a usable cast crank. You want to mag check the deck, coolant holes to head bolt holes. This is a common crack area, sometimes you can see with the naked eye, most times you need something with magnetic particle checking tool to verify if there is cracks or not.
 
#3 ·
What he said.^
I used Scat Cast 9000 crank and their 5.4" I-beam capscrew rods in my 331. Decent quality at a really decent price. If you are staying NA and keeping the RPM's under 6500 or so, they will be fine.
There are some crack detection kits available from MSC and other industrial supply houses. But even the dye penetrant / UV style will run $60-100.

A good relationship with a local machine shop will go a long way.
 
#4 ·
Cracks was one thing I forgot to mention but you both brought it up. So my plan was to dye pen the most common problem areas myself. Where else should I check besides around the head bolt holes and coolant passages?

This will be a very mild NA engine under 6500. Not looking for anything crazy. Thanks for the input!
 
#6 ·
I've noticed that it can be difficult to find a 342 kit. I guess most suppliers just assume at least 30 over for a kit. I really don't think I need that with this block. Should I look at building my own rotating assembly? Kit would be easiest, but I have time.
 
#7 ·
Yea as stated try to find a machine shop and become friends. We have a bunch of local engine builders and racers that we do favors for all the time. If its someone we know they usually drop the block off and we inspect them for beer money. But I suppose if someone did bring a block by it would only be $100 or so to look it over.
 
#8 ·
I bought some GT40 heads and explorer upper/lower intake because I found a decent deal but what I really need to decide on is the rotating assembly (namely the piston volume) and cam so now I'm looking at compression ratio. I definitely want to be able to run pump gas. Based on online calculators the kits I'm looking at would put my stroker at 9.46:1 or 9.62:1 static CR with GT40 heads (assuming 64cc chamber) and 6.5cc or 5cc pistons. I'm planning to run an E or F cam (keep in mind this is a "budget" build!) and based on calculators that puts the low/high dynamic CR between 7.75:1 and 8.25:1 based on options. I know there are loads of opinions out there but a common theme I've read is that you want to keep dynamic somewhere between 7.5 and 8.5 to avoid detonation. The 5cc piston with E cam would put me at the estimated 8.25:1 dynamic. Would I be pushing it there? I don't want any possibility of issues with pump gas.
 
#9 ·
You’ll be fine, we have 93 octane down here as I’m sure y’all do too.

If you keep the coolant temps down to around 180* it will help with pinging, but you’ll probably never see it.

E cam will be fine for a cheap build, just buy a used one. Usually around $100

Edit: wait, you’re using gt40s and an e cam for a stroker engine?
 
#10 ·
The above post by strokeme is woody from fordstrokers. If you go to sbftech and look up a 306 build and 300hp you should find a thread he wrote on how to get there. Your build is possible but may not need the stroker kit. Pick the hp goals and call woody. You limit yourself with the HCI choices you make. Also check on the ring and piston package you can get. Then your machinest can hone the block right.
 
#12 ·
I will check into that. As I stated in my first post, this is a fun budget project for me. Not necessarily looking for max hp from this build, but a 347 can offer some nice low end torque. I'm not racing. I spend most of my time just rolling on the throttle at low rpm. I'm just wanting to learn and have a streetable engine in the end. I realize that's probably foreign to a lot of people here.
 
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#22 ·
You’re still using a stock block, and chiefly worried about the rotating assembly being pushed too far? I have several buddies who cracked the block, but none who said the RA kicked the bucket.

Put some actual induction parts on the motor. Letter cams and GT40s have their place and it’s when the budget is 50 cents. Throw that money you were gonna use for rotating assembly at your top end, some good link bar lifters, and have the 347 guys call you a liar when you tell them you have a 302.
 
#26 ·
...

... Throw that money ... some good link bar lifters,...

When are the link bar lifters needed or more reliable? Do they need to be considered for an engine shifting at 6000rpm, or another at 5500rpm? That's one of a few items I haven't decided about yet.


I also agree with the others. If the short block can go back together for little money and time, I'd make a first step with mid level HCI parts. There are tons of parts to consider outside of the short block, which all contribute a bunch to overall power, and reliability. I'd work on most of those, and at some point soon, you will more clearly see a goal to aim for. Then the choices and budget will be simpler to handle.
 
#23 ·
I am going against convention here so I guess these replies can be expected. Nowhere did I ever say I was worried about pushing the RA too far. Nowhere have I said I'm looking to max out the HP on the stock block. Nowhere have I even said I had specific goals for this engine. What I've said is I'm building a budget stroker for fun and I've only asked pointed questions about block inspection, stroker kits, and compression ratios. I understand I will choke a 347 with GT40 heads/intake and an alphabet cam is less than ideal. I'm ok with that. When I'm ready, I'll sell the heads and intake for what I have in them, throw some nice aftermarket parts on, get a proper cam, and probably max out the capacity of the stock block. When I get to that point I won't have to pull the motor to stroke it, I'll be doing all that work under the hood. That may not be what most would do, but is that so crazy of a plan?!
 
#25 ·
That may not be what most would do, but is that so crazy of a plan?!
Yes, yes that is lol. It’s your call man, we’re just trying to steer you in, what seems to us, is the most logical direction.

In the end, it’s your car and money.
 
#28 ·
I think we need some actual goals defined or more information on how you drive the car to give any advice that doesn't involve spending money needlessly or twice.

What do you actually use the car for?
What's your current engine/driveline setup?
What do you want the car to do that it isn't doing currently?
 
#29 ·
The car is more or less a grocery getter and rarely goes more than 20 miles from home. Current engine/driveline is bone stock except for what's in my sig. I bought the car with no engine and pulled the engine from a beat up hatch, rebuilt the T5 and rear end, and got it on the road. The engine is tired. My driving habits are a bit mild, some may describe it as a little boring lol. What I'd like is more torque to put me back in the seat a little more when rolling on the throttle at lower rpm and I thought a 347 would do the trick. I don't really want to build on the old tired stock motor, and I don't want to pull it out to rebuild it because I want to continue driving it. That's why I decided to buy a block and build something on the side.
 
#30 ·
Nevermind the numbers, I think these are the kind of curves I'd be happy with. I guess to put it simply, I'm looking for plenty of low end torque and don't really care what's going on above 4500 because I'm going to spend little time there. Does that help?

 
#31 ·
I mean it sounds like you want to build and tinker either way. If you're starting with a bare block you might as well do a stroker.
I'd run the GT40 heads you have. Just get a custom cam done and a good set of valve springs.

If/when you want more power put on a better set of aluminum heads.

It's not the most efficient idea but it's not a completely terrible idea for your goals.
 
#32 ·
I mean it sounds like you want to build and tinker either way.
Yes! This is what I like to do! This is mostly a project I decided on because I had run out of other projects in my shop. Like I said before, if the performance is a bit anemic to start with I'm ok with that. I was just thinking it'd be good to at least build a solid base to grow on later.
 
#33 ·
In a world of instant gratification, something like this is incomprehensible.
You've got the bare block sitting there... gotta spend $ for crank/rods/pistons anyways, may as well stroke it ($ difference is minimal)... I too would build the foundation.
There was a user here running a 347 with E7te's, hydro roller... going low 11's n/a... he may have had some weight reduction, don't recall.
Not a whole lot of budget 306's going low 11's, much less fancy top end ones...
I think you are on the right path if long term is your goal.
 
#35 ·
Long term for sure. No intentions of ever selling the car. Always wanted one, probably a real good thing my parents wouldn't let me have one when I got my license. Got this one rolling down the road after plenty of B/S/T. Plan now is to just tinker with it from here on. So far I've concentrated most on suspension/chassis/braking and cosmetic upgrades. Oh, and reintalling the A/C that was deleted from the hatch donor car. I like to be comfortable too. :)
 
#37 ·
I am far from an expert... rather on the opposite end of the spectrum...
My stock STR Jeep does not have link bars from the factory, and, there are some forum posts on lifters that have "turned"(?) in their "bore"(?)... its not got a sporty cam (as would be considered by this crowd) only spins to 6krpm and has an auto trans, so, no missed shifts.
Not sure what causes them to turn (float/bounce/springs on the edge of too little pressure/tired springs/push-rod flex... or just harmonics in general causing a perfect storm... maybe all of the mentioned... ?) but in my simple logic, anything running a sporty cam/spring package should consider it... and if it's a standard which provides opportunity for missed shifts... well... insurance ??
Maybe Ed or Mark will chime in.
 
#38 ·
Trying to understand. Are you saying some people have had their roller lifters turn in a roller block (dog bone failure, wear, etc)?. I thought link bars were only needed when putting roller lifters in a non-roller block.
 
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