Curiosity Question...

[McKenney]

If one were to acquire a 5AGE crank, and had a 7AFE block wouldn't that solve the problem of the 7AGE being a weak bottom end? They're both longer stroke crankshafts and from what I could dig up mostly the same as far as size except for the 5AGE crank being an 8 bolt and much stronger. I was curious and couldn't find any info about anyone building one. The 5AGE stuff is scarce, but thought it might be kinda kewl.

[dr.occa]

i'm not up on my 7afe info but my first question would be: are the mains between the cranks the same?

[GTSRolla34]

Mains should be the same. Bill Sherwood has mentioned using a 4AGE crank in a 7A block on his website. The 5AGE is a stroked 4A crank, so it should work. Are you talking about the HKS stroker crank? I think the real benefit to your inquiry would be to get the stroke measurements for the 3 cranks and see what kind of rod/piston combo to go with. As far as fitment goes, it should fit.

[McKenney]

I was just wondering... Thinking about strength and all. Are the 7A blocks 7 rib or 3?

[dr.occa]

Mains should be the same. Bill Sherwood has mentioned using a 4AGE crank in a 7A block on his website. The 5AGE is a stroked 4A crank, so it should work. Are you talking about the HKS stroker crank? I think the real benefit to your inquiry would be to get the stroke measurements for the 3 cranks and see what kind of rod/piston combo to go with. As far as fitment goes, it should fit.

i vaguely remember some of the details in bill's pages. the 4age crank in a 7a block wasn't going to be much of a benefit due to the deck height on the block and vice versa (regarding 4ag block skirt clearances which could be solved with a grinder and a steady hand).

stroke info:

7AFE: 85.5mm
1, 3-6, 8A: 77mm
5age: 83mm

[Projectgofast]

When ever people post about the 7age they seem to focus on the 6 bolts vs 8 bolts on the flywheel, ok so it may be slightly weaker
but the fact is most poeple will never make enough power to ever notice or for it to matter. The rods are a weak point but I havent had them fail yet, but there are after market forged rods availible, building a 7age is a cheap way to make some tq I've been running mine for well over a year and I beat the piss out of it. Im just surprised there isnt more of them around the junkyards are full of 7afe's

[dr.occa]

... Im just surprised there isnt more of them around the junkyards are full of 7afe's

i'm with jason on this.

it may not be as rev friendly as the 4age but you don't need it to be.

[mooreofit]

the 7afe crank is not weak and easily holds 500chp


http://www.cardomain.com/ride/2131056/9" onclick="window.open(this.href);return false;

the weak point was the rods. belfab has since solved this issue.

[dr.occa]

it's not that i'm concerned with the weakness of the crank or rods, it's the oil passages in the crank itself. it may be negligible by some but it is a concern when keeping the assembly in upper rpms for long stints. the 7a crank does not receive a continuous feed of oil around the full circumference of the main and rod journals. it's possible this may be resolved with an accusump to keep oil pressures at a dependable constant. part of the crank's design was also to be economical as a mass produced crank.

[GTSRolla34]

When ever people post about the 7age they seem to focus on the 6 bolts vs 8 bolts on the flywheel

Beyond strength and weakness it could also come down to an availability concern. Some may already have light-weight 4AGE flywheels and would like to reuse them. I don't know enough about the 7A series to know flywheel information as far as size, weight, aftermarket support, or whether they clear the bellhousing. 4G63 cranks are 6-bolt and they will support plenty of power, so I would think there are more concerns than just strength.

[mooreofit]

lightweight flywheels are available thru mike at nst. loosing hydrodynamic wedge is not an issue from what i have seen. the only issue hear about is the out of square bore and stroke and overrevving vs power output due to the exteded throw of the crankshaft

by the way this is by no means a new idea. see corollacarclub and search 7age or ge head swap. there's a bunch down in the land of oz too

[Projectgofast]

Beyond strength and weakness it could also come down to an availability concern. Some may already have light-weight 4AGE flywheels and would like to reuse them. I don't know enough about the 7A series to know flywheel information as far as size, weight, aftermarket support, or whether they clear the bellhousing. 4G63 cranks are 6-bolt and they will support plenty of power, so I would think there are more concerns than just strength.

I think the 4AC runs a 6 bolt flywheel as well, you can just run one of them, I can't remember if I got a 7a flywheel or a 4ac but I'm running a stock gts clutch

[dr.occa]

well, in spite of some of the "cons", i'd still rock a 7age setup. i'd run a stock bottom end even.

for long term abuse, i'd go with aftermarket rods alan mentioned, balance them, then acl rods, mains (2 sets and run full groove) & thrusts (4B1680, 5M1695 & 2T1695 respectively) and an accusump from canton racing.

that should do for me.

[mooreofit]

thats a qestion ive been waiting to get answered for months project. i was wondering if the gts clutch would bolt to my 7afe flywheel im bolting to my 4afe crank.