achalmersman stroker 4.1 build (291 block)

[achalmersman]

Well, I'm progressing on this again. I have the crank, rods, pistons, bearings. The cam and rings are on their way. Today I worked on clearancing the #1 rod to oil gally tube. I layed the crank in the block and hung one slug and rod to the number 1 journal. Snuck up on the grinding until I could sneak a 0.030" torch nozzle cleaner through the gap. While that rod was hung I measured my rod side clearance to be 0.006" and the rod small end to piston clearance at 0.017". After machining the rods for the better clearance in the neighborhood of 0.010-0.012" my little end to piston clearance should open up as well. Next will be clearances to the cam once the camshaft gets here. After that the rotating assembly will go to the machine shop to have the rods milled, and the assembly balanced. Pictures included

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[ek02]

You can gain another .030 rod bolt to oil galley clearance by rounding off the head of the rod bolt slightly. It doesn't take much and saves any more grinding on the block. I like .060 clearance to be safe. Your build looks very good so far.

 

[Steve V]

Looks very nice! Did you get Molnar rods? I got 3 sets in Friday and they are way nicer than the ones GN1 sells. Looks like they won't need any grinding/milling for cam clearance . Still need to verify. They come with ARP bolts as well and GN1s have Chinese no name ones. Good Luck

 

[achalmersman]

Looks very nice! Did you get Molnar rods? I got 3 sets in Friday and they are way nicer than the ones GN1 sells. Looks like they won't need any grinding/milling for cam clearance . Still need to verify. They come with ARP bolts as well and GN1s have Chinese no name ones. Good Luck

Yes these are Molnars. Yes I agree I am very happy with the quality. ARP2000 bolts and they ship them with lots of metal. Anybody using these rods should expect to have to machine them for side clearance but at least you can take metal off. Can't put it back on lol. I'm hoping I have no cam interference too but have to wait till it gets in to find out. The crank is a GN1 4340. Hoping it gets the green light from the machinist when I have him balance and check. I put a dial indicator on the 2 center mains yesterday and they seemes straight. Havent measured any journals yet for taper or anything.

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[ek02]

The Molnars cleared my cam, but I still took a little off to be sure I had more than enough clearance. I checked mine with a feeler gauge from the opposite cylinder where I could get my hand in the bore. The Molnars are tight on side clearance. I left them at the stock side clearance on my spare engine since I don't run that one hard. The engine I run hard has way more on a set of CAT H Beams (with ARP2000 bolts).

 

[BEATAV8]

The reason you need steam holes on a 4.1 is because the bores touch inside the water jacket. That means the air bubbles between the bores on the bottom side can't flow out. Therefore you have to give them a way to float up to the heads and into the water jacket. Since 8445s aren't built with siamese bores in mind, they don't have holes.

I’m wondering if drilling the steam holes is required for a street car. I think that a few minutes of driving would flush out any trapped bubbles?

 

[1972chevy]

subscribed

 

[Chevman2448]

Im subscribing as well. Im running earls pistons as well.

 

[marleyskater420]

Looks very nice! Did you get Molnar rods? I got 3 sets in Friday and they are way nicer than the ones GN1 sells. Looks like they won't need any grinding/milling for cam clearance . Still need to verify. They come with ARP bolts as well and GN1s have Chinese no name ones. Good Luck

Steve, Molnar does design rods with extra cam clearance. I was at Duttweiler's shop today and showed him the custom billet rods that Molnar made for us (RPS) and his first comment was "These should clear the cam. I see where he added some clearance on these." Which is exactly what Molnar told use he did with the design when he first made them.

In addition to that, Duttweiler did say that I could quote him when he said our rods could take the 1,500-1,600hp I was shooting for, and said "They should be adequate", since things like detonation can always blow stuff up...but it was nice to hear our $900 rods could take the power of $1,600 ones

I will post up later some pics of a regular Molnar rod and our custom piece so you can see where I'm talking about. Duttweiler didn't say that the extra clearancing on the rod would affect its' power handling, so I would ask Molnar if he could machine sets for you like these.

Gimme a few minutes and I will post the pics up. It is 12:20am and I have been on the road since 1pm driving back from the Buick Bates show....

 

[marleyskater420]

Pics.

 

[434nova]

Any update on this build?

 

[black owned]

Any update on this build?

Ttt

 

[grass doctor]

following ...

 

[achalmersman]

Wow I poked my head in here for the first time in a long time and didn't expect to see my thread at the top of the 2nd page. Im sorry to report you will be depressed as I have become. I sent my block and parts to the machinist I used for the line bore / cylinder hone almost 2 years ago to go through it and set the main clearences / rod clearences, / balance, gap rings, etc. Ive called in 3 or 4 times over 2 years and he hasn't made much progress. December will actually be the 2 year mark. I think I'm going to call again soon and ask if its going to be done before spring. Otherwise I want to come get it. Ive got many thousands of dollars worth of parts sitting over there. Unfortunately I made the mistake of telling him I wasn't in a rush when I dropped it off. I didn't mean "take several years".

I think one of the reasons I havent kept pushing him is things have changed family wise. I do a lot of competitive shooting, specifically PRS here recently. We also had our first baby in Feb so he's 8 months old now. I dknt have money sitting in the bank waiting to pay the machinist so it would probabky go on the credit card, but at this point that's what I'd do. I want it back and I do want to get my car built the way I want it. Im still able to drive the car, but its turned way down right now. I hope to get back on this soon and produce some interesting pictures / posts. Right now its depressing thinking Ive probably got 12-15k worth of shit laying around and nothing to show for it.

 

[434nova]

Wow I poked my head in here for the first time in a long time and didn't expect to see my thread at the top of the 2nd page. Im sorry to report you will be depressed as I have become. I sent my block and parts to the machinist I used for the line bore / cylinder hone almost 2 years ago to go through it and set the main clearences / rod clearences, / balance, gap rings, etc. Ive called in 3 or 4 times over 2 years and he hasn't made much progress. December will actually be the 2 year mark. I think I'm going to call again soon and ask if its going to be done before spring. Otherwise I want to come get it. Ive got many thousands of dollars worth of parts sitting over there. Unfortunately I made the mistake of telling him I wasn't in a rush when I dropped it off. I didn't mean "take several years".

I think one of the reasons I havent kept pushing him is things have changed family wise. I do a lot of competitive shooting, specifically PRS here recently. We also had our first baby in Feb so he's 8 months old now. I dknt have money sitting in the bank waiting to pay the machinist so it would probabky go on the credit card, but at this point that's what I'd do. I want it back and I do want to get my car built the way I want it. Im still able to drive the car, but its turned way down right now. I hope to get back on this soon and produce some interesting pictures / posts. Right now its depressing thinking Ive probably got 12-15k worth of shit laying around and nothing to show for it.

Sucks on the machine shop deal. I seen it happen many times before. Between them and body shops I don’t know who is worse. But good luck, hope your up and running soon.

 

[Boost231]

im in the same boat, coming up on 2 years as well. Was making progress till this whole coid thing hit now everyone uses that as the reason for the slow down. Trying to get head gaskets and custom arp bolts is taking forever.

 

[grass doctor]

where or who is the machine shop ?

 

[achalmersman]

Its nobody on this forum. I'd rather not put his name out as I'm not trying to start anything. He's a nice guy I just think he's overworked etc.

 

[Jerryl]

In my experience, most machining projects have a typical 9-15 month wait unless you have them on standby. A lot of it is likely related to setup amortization and profit margins, unless of course you pay top dollar to get your project in front.

 

[grass doctor]

Its nobody on this forum. I'd rather not put his name out as I'm not trying to start anything. He's a nice guy I just think he's overworked etc.

10/4 ...just curious ...especially if its no one on the forum ...interseting...hope you get her done or the best alternative..