engine options

slagburn

I just ran my MJ at the track yesterday. Sea level equivalent, 14.0 without juice, 11.99 with the 200 shot. OK, but need more motor. I think right now the bottleneck is my untouched 291C heads. I've got a 292 cam in it, roller rockers, 10.8 compression, Torker intake, headers, good ignition system. This has only produced 261 rwhp without power adders. The way I see it I have a few options. I have a set of opened up heads with a 64 cc chamber instead of the 51cc's now on it. I could get those heads back on with the same pistons and drop the C/R down to about 10:1 and go twin turbo, but I don't know how the stock 401 crank and rods will like that. Probably better than 200hp worth of N20 though. Another option is to keep my dished pistons and get the Edelbrock heads, or even the new HLR splayed heads. Maybe a change to flat tops depending on the HLR chamber size. Or, I could go the custom bottom end route and go with Chevy rods, offset grind the crank or whatever is usually done to get more cubes. I don't really know what the parts and machining list is for this kind of work. I guess what I'm looking for is a little help in choosing a path. I'm not made of money, so what's going to be the best combination of expense and durability? I'd like 400 rwhp normally aspirated, or 600 with turbos. Am I asking too much of the old AMC? Thanks...

jeepsr4ever

I would go the stroker route and up the compression. If this is a strip only motor dont be afraid of 12-1 and/or some head work and stroking it with either honda bearings and a chevy rod or a chevy rod and chevy bearing.

fuzz401

I just ran my MJ at the track yesterday. Sea level equivalent, 14.0 without juice, 11.99 with the 200 shot. OK, but need more motor. I think right now the bottleneck is my untouched 291C heads. I've got a 292 cam in it, roller rockers, 10.8 compression, Torker intake, headers, good ignition system.
This has only produced 261 rwhp without power adders.

my cj does 13.495 at sea level with just carb - weighs 3500 lb
401= 12.cr - air gap intake - 750 elde carb - crower 292 solid cam - roller rockers - 6090 heads - 37" swampers - 4" lift -th-400 trany-2400 stall converter - headers - stock dizzy with a different modual

I would think you should get more then that out of it

Mudrat

fuzz401 wrote
my cj does 13.495 at sea level with just carb - weighs 3500 lb 401= 12.cr - air gap intake - 750 elde carb - crower 292 solid cam - roller rockers - 6090 heads - 37" swampers - 4" lift -th-400 trany-2400 stall converter - headers - stock dizzy with a different modual

I would think you should get more then that out of it

And I still think your crazy for pushing a CJ at over 100 MPH!!! On the other hand, you have portmatched and polsihed right :t:

fuzz401

ports matched = yes exhaust ports polished = yes bowls blended = yes 100 mph = not yet 98.7 fastest to date :t: :mrgreen:

Lifted79CJ7

Mudrat wrote
And I still think your crazy for pushing a CJ at over 100 MPH!!! On the other hand, you have portmatched and polsihed right :t:

On swampers, no less!! :?

jeepsr4ever

I can see it now "Z" rated TSL's :mrgreen:

fuzz401

might be what I need a 200 shot :t: :-| 111!!!

jeepsr4ever

:-|

Lifted79CJ7

fuzz401 wrote
might be what I need a 200 shot :t: :-| 111!!!

Blown7

fuzz401 wrote
ports matched = yes
exhaust ports polished = yes
bowls blended = yes
100 mph = not yet 98.7 fastest to date :t: :mrgreen:

I think if you dropped the windsheild and ran the air in your face that would be all you need to break 100 MPH + Jeff

slagburn

I think I'm gonna do a single turbo and see what happens. In a month or two I'll pull the lump back out and check out the bottom end, then swap my ported 58cc heads back on it to drop the CR, then turbo time. Enough of trying to figure out why I can't get any HP without a power adder, I'll just keep one installed and enjoy the ride.

Lifted79CJ7

Hey, if you add a turbo, would you mind adding any info HERE? I am really interested in this right now....

:lo1l: Jack