I'm interested in upgrading my current budget short block to something that can reliably handle ~700RWHP via 76mm turbo (say 6,500 rpm limit). I'd like to avoid a $4,500 shortblock if at all possible at this level.

CURRENT:
Stock crank/rods, 4.000 SRP's and ARP fasteners.

I'm half tempted to swap out my stock rods for some decent 5.7 H-beams, stud the two bolt main, and re-use my current std. bore dished SRP's. Looks like cost for this type of DIY job would be $1200-1500. Not sure what the current leakage is with the stock 35K mile std bore though. If it ends up needing to be bored with new pistons that could change the scope here.

Do you think that'll get the job done?

I've been bouncing back and forth with the idea of the above 'budget' forged rod motor or purchasing a complete splayed main, Callies SB in the ~$4K range.

Would be going into a street car with as much as I can get out of a single TC76mm and pump gas. Mild heads and cam.

Help talk some sense into me

Thanks,
Scott.

 

well, another cheaper alternative would be

4.030" -20.10? cc dished speed pro pistons (415 for the set)
5.7 forged h-beam eagles (490ish with l19 bolts, or 335 w/o)
and stock crank, you would be good for about your 700RWHP

add in another couple hundred for a crank (600 prolly), and you'd be good for 1000ish

no need to go crazy on the bottom end for a mild build

 

700RWHP is not even close to a "mild" build. We are talking about 3 times the power the motor puts out!

Be safe

Splayed 4 bolt mains
forged crank....eagle, callies etc
5.7 H-beams Forged
Forged piston -20 or more (depending on heads)

Jay

 

Scott, I'd keep the max rpm below 6500---- use a cam that peaks in the 56-5800rpm range, shift at 6000rpm. That will help with the longevity of the shortblock.

 

Turbo will be all done around 6000, so don't worry about spinning to 6500.

Eagle rods are good, but the regular bolts are junk. ARP2000 or L19 is a must.

I think the stock crank is ok.

The 2 bolt mains might be a problem. I'm at 700 rwhp with a TH350 (~850 rwhp M6 equivalent) with a 4 bolt billet conversion. My block has fretting damage under the main caps from walking. 2 bolt will be worse.

Do a search on turbomustangs for the grenade. The dude has a stock rebuilt long block TPI motor with all junk parts running twin stock GN turbo's at 20++ psi boost with a shot of nitrous at about 700 rwhp total. His has severe fretting under the mains and he admits its days are limited.

 

yup, its that much more than stock...but its also not an "extreme" build either compared to what we've been working on lately....

 

Thanks guys,

Still debating with myself how much I want to put into the car in this economy. A shortblock done right is no small chunk of change. Might just throttle the turbo back.....

-Scott.

 

Scott, any idea when you will get a chance to get some numbers on the current setup (dyno or track)?

 

I'd love to max out the TC76 with you're kit, but, I think we'll be on a BUDGET motor this year, so we'll see.
-Scott.

 

I hear ya Scott... you could always try and get results for 7psi... or whatever you are running.

 

Send me a trial of all of your kits and I'll give you real world numbers for each of them.



lets start with the T88 kit first!

Something I have always learned building an engine is that I always go way over my "budget" I set for myself. To be honest I would rather run your current setup longer, and build a great engine to throw in there months down the road. Instead of throwing in a half a$$ed attempt. You will honsetly cost yourself more in the long run. Especially seeing 700rwhp+ I cant see a 2bolt main lasting that long, or a stock crank taking that kinda abuse. I just would not risk ending up having to build a motor with everything you should have put on it in the first place.

 

 

Starting to look past the 'budget motor' thing and get a serious shortblock in the car. It's just a huge expense and hard to justify at first glance.

I'm thinking the stock crank and studded 2-bolt might be ok for a 600whp streetcar. I have a dished SRP piston in there currently so I could simply put in some $300 forged rods and main studs; call it good for ~$600 plus tools/mics. BUT, I know I'll be right back here, in this very spot real soon. So, it's not so much throwing away the $600 for 600hp but rather knowing I need to re-think, teardown, yadayada everything again real soon because I won't be happy.

If I wanted 600hp the above would be the best bet for a street car.

Problem is I got a few parts on the car now that want to make more than that

I'm looking at a Callies crank (either dragon slayer or Compstar), compstar rods, TBD pistons, splayed mains etc. Still pricing everything out. But we'll see. Hopefully things come together by mid summer this year.

Thanks for all the recommendations,
Scott.

 

600whp is all i'd run on a 2 bolt motor. splayed 4 bolt conversion on that block will give it the ability to run almost 1000hp if the internals are good.

For what its worth, i'm gonna run eagle forged crank/h beam rods with ARP2000 bolts, JE turbo pistons, and stock 4 bolt mains with arp bolts. Looking for 700whp with T56 manual. May try to hit 750-800 in kill mode but i'll never run it much with that power. 700 is all i'd feel comfortable racing and that will put me well into the 9's which is MORE than enough for me. I'm already 10.6's with 520ish whp. a 200 shot basically should cut close to a second and add 10-13 mph or more.

 

Anyone have cost for the splayed conversion. I've seen ~$150 for 3 center caps but can anyone provide a good estimate on machine work cost?

-Scott.