Slant 6 stroker kit?

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AussieDart

AussieDart

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Hello Everybody, The other day I was looking at the slant 6 block (225) that I have and decided it would make a nice project for me. I have looked high and low on the interwebs and on this site but cannot find anything. Can anyone tell me if there is a producer out there that makes stroker kits for the slant 6? I definitely don't want to be making anything myself, I just want a kit that I can bolt together. Appreciate any advice you may have. And here for your amusement are a couple of pictures of the block on my home made engine stand that I built from scrap that I had lying around the garage.
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To answer your question, I’ve never heard of a kit to stroke the 225. Maybe because It’s already got that long stroke.
 
65 Dartman said:
To answer your question, I’ve never heard of a kit to stroke the 225. Maybe because It’s already got that long stroke.
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Yes I think you could be right. I keep reading about stroking a 198 with a 225 crank but that is all I have come across. Nothing about stroking a 225.
 
Back in the 70’s a machine shop I knew of used to install ford pistons with Chevy rods. This took advantage -if memory serves me right... of Off set grinding the crank with above deck pistons. Raising the compression and shorting the stroke. The drawback was the head did not flow enough on the higher rpm. The shorter stroke allowed for much higher revs. I know this does not answer your bolt in kit question. BUT if you wanted to create a kit and you said you did not- it gave a possibility. Hate to waste this trivial info in my brain. Does me nothing to take this nugget to the grave. Lol!
Good luck in your quest.
Syleng1
 
Syleng1 said:
Back in the 70’s a machine shop I knew of used to install ford pistons with Chevy rods. This took advantage -if memory serves me right... of Off set grinding the crank with above deck pistons. Raising the compression and shorting the stroke. The drawback was the head did not flow enough on the higher rpm. The shorter stroke allowed for much higher revs. I know this does not answer your bolt in kit question. BUT if you wanted to create a kit and you said you did not- it gave a possibility. Hate to waste this trivial info in my brain. Does me nothing to take this nugget to the grave. Lol!
Good luck in your quest.
Syleng1
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Thanks. Any info is helpful.
 
There was an explanation or video link posted somewhere on this site about the stock 225 slant six already having too long of a stroke to bore ratio to produce the best power.
 
The only info I have read on stroking a /6 (an already over stroked engine) is off-set grinding the crank, leading to custom rods and pistons.
 
THe 225 CAN be stroked by offset grinding the crank, buy my GOD it already has a 4 1/8" stroke. It doesn't need help "THERE". It needs a better cylinder head, because the 225 head was never redesigned. They simply slapped the 170 head on it and kept on truckin. The only head redesign was done about 68 I think all across the board.
 
RustyRatRod said:
The only head redesign was done about 68 I think all across the board.
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I don't have my Doug Dutra book handy, but i seem to recall another head combustion chamber redesign in 1975 or '76. That is when they also did away with the spark plugs tubes. I think.
 
J Glenn said:
I don't have my Doug Dutra book handy, but i seem to recall another head combustion chamber redesign in 1975 or '76. That is when they also did away with the spark plugs tubes. I think.
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I'm not aware of another major chamber redesign. Surely anything in the mid 70s wouldn't be conducive to making power. lol
 
AussieDart said:
Yes I think you could be right. I keep reading about stroking a 198 with a 225 crank but that is all I have come across. Nothing about stroking a 225.
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The references you're seeing are regarding using a 198 rods with a 225 crank, with 2.2 four-banger pistons. Referred to as a "Long Rod" engine, a "Non-stroker Stroker". Displacement remains about the same, but this moves the pivot point in the piston and allows the use of lighter, (more) modern pistons and rings. I know this because I built one of these engines 15+ years ago. Still have it in a retired Swinger in my garage.
 
J Glenn said:
I don't have my Doug Dutra book handy, but i seem to recall another head combustion chamber redesign in 1975 or '76. That is when they also did away with the spark plugs tubes. I think.
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You may well be right.
 
I thought the chamber redesign came around 1968, and that chamber design was relatively unchanged when they changed to the peanut plug head. I also think that the article about the subject is in the"articles" section of the slant 6 forum.
 
I suppose we in Aus are so lucky as we abandoned the slant six in favour of a hemi six in 215 245 and 265 sizes. the bore and stroke of the 265 is 3.91 x 3.68 with a comp of 10.5 to 1 on the performance E49 engine producing 302 HP from the factory or 325 HP with the bathurst spec cam.We now have available a Alloy head and one person I know of has a drag car with 265 turbo doing high six second qtrs with well over one thousand HP.
 
A 170 block with a 198 crank. The 198 will need the counter weights turned down for clearance.
 
I need a scrap jaguar 6 head and a bandsaw....looks doable for a cross flow dohc head to fit the 6. Timing belt off the front hub... Get bolt spacing right and water feed it from the end. Anyone got a old jag laying around? Bore spacing 4.13" on jag to 3.98-4.00 on a slant.
An olda Aurora 4.0/Northstar V8 head has 4.00 bore spacing 101mm. Same as slant. ( i made my /6 fuel rail from one) Take 2 heads, chop off the last cyl of each and make em 2 3cyl heads inline on a 6 like Isuzu NPR truck. Then you get a 4v per cylinder. Dream a little dream.....
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It's already 4.12 stroke.

It needs a cylinder head. 1000.00 worth of work for enough air for about 400hp.
At least that's what I charge for one ready to go.
 
pishta said:
I need a scrap jaguar 6 head and a bandsaw....looks doable for a cross flow dohc head to fit the 6. Timing belt off the front hub... Get bolt spacing right and water feed it from the end. Anyone got a old jag laying around? Bore spacing 4.13" on jag to 3.98-4.00 on a slant.
An olda Aurora 4.0/Northstar V8 head has 4.00 bore spacing 101mm. Same as slant. ( i made my /6 fuel rail from one) Take 2 heads, chop off the last cyl of each and make em 2 3cyl heads inline on a 6 like Isuzu NPR truck. Then you get a 4v per cylinder. Dream a little dream.....
View attachment 1715621138
View attachment 1715621136
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Well. What ya waitin for? Junkyards are full of northstars.
 
Why the 198 crank in a 170? With an overbore you have a 210. Only 15 cu in below a 225 and at least 1000 RPM more.
 
Hyper_pak said:
Why the 198 crank in a 170? With an overbore you have a 210. Only 15 cu in below a 225 and at least 1000 RPM more.
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Yeah but he left out the .100 over bore. That's what I was gettin at. They take .100 fairly easily so I wonder if you couldn't bore the 170 enough to make it a 225 with the 198 crank?
 
Personally, I don't like the idea of a bored and stroked low deck slant. Too much work, and money. Too few advantages. Only advantage is Maybe, a little more RPM then a 225, but not more then a 198 (you use the 198 crank) unless the special piston is light enough.
A 170 starts out as a zero deck motor, so the only way to get a compression increase with a flat top piston is to mill the head, which will give you somewhere between 10 and 11 to CR. A 225 engine can get around 13 to one with common parts, and milling the deck and the head.
 
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