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86 Engine Swap

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brian86

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I HAVE RECENTLY PURCHASED AN 86 L98 COUPE WITH 167,000 MILES ON IT. THE ENGINE RUNS SMOOTH BUT IT DOES NOT LIKE HIGH RPM'S. I HAVE A 350 4-BOLT MAIN ENGINE THAT IS LIKE NEW IN A PROJECT CAR. MY QUESTION IS , CAN I USE THE SHORT BLOCK 350 IN PLACE OF THE L98, IF I USE THE TPI ON IT? ALSO IF SO DO I HAVE TO USE THE L98 HEADS? I HOPE SOMEONE CAN HELP ME WITH THIS. THANK YOU.:confused
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,237
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
Unless you go to an aftermarket intake or modify your existing runners somewhat, you're still gonna run out of wind at higher RPMs. Your stock TPI doesn't breath very well. :(
 

JT ZR-Won

Well-known member
Joined
Dec 6, 2000
Messages
1,273
Location
Bradenton, FL
Corvette
'90 ZR-1 #365 (SOLD...but Dad's got it now)
Brian, welcome to the CAC:D Like Ken said, the stock TPI unit isn't to friendly above 4500 RPM. If RPM's are what you're looking for, I believe the Mini Ram is the best setup. You'll lose a couple of pounds of torque, but you'll make plenty of horsepower to make up for it. The only thing that sucks is the mini ram isn't to wallet friendly:( For a cheaper alternative, the Accel Super Ram is supposed to be pretty good also, but doesn't produce the #'s that the mini ram does............good luck & keep us posted

Jay
 

corvette66

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Nov 3, 2003
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519
Location
Mattawan MI
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1969 427
...

Jay, do you know the price on a mini ram, or where they can be purchased? just wondering. I Would like to take a look at them.

rock on guys

dan
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,237
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
Another very old thread revived! :L

The Mini-Ram is available from Tuned Port Injection Specialists (TPiS), and they list for
  • 500-505 Mini-Ram II Manifold, fits stock/aftermarket heads using Fel-Pro 1204........$895.00
  • 500-518 Mini-Ram Intake for heads requiring a Fel-Pro 1205 gasket........$895.00
  • 500-519 Mini-Ram Intake for heads requiring a Fel-Pro 1206 gasket........$895.00
  • 500-530 MR III for GM Fast Burn Heads........$895.00
The following is from the TPiS web site:
This fabulous one-piece casting is ideal for the serious car nut. If used as a replacement over a stock Tuned Port intake, on a mild 350ci motor, you will see a 75-95+ HP gain. If you build the motor on the mild side, i.e. small cam and some porting, stroker motor, 100-125+ HP,over the stock or modified TPI intake is very possible. If you go on the wild side you will be able to exceed any single four barrel power numbers, all with greater driveability and economy. Installs on existing TPI vehicles with just our Fuel Rail Kit and Level VI Prom. Use the mini-ram to replace and out-perform any carbureted system. We have been driving this manifold for over ten years. It has wonderful throttle response, delivers more torque from 2000 to 2700 RPM than a stock or modified TPI, and gives a great rush of power from 3500 RPM to 6500 RPM. The reason the TPI intake is so restrictive is due to its intake runner length, which is 17 inches long! Your typical carburetor intake is about 5-6 inches long, and our mini-ram intake is 3 inches long. The shorter the runner the higher the peak RPM, the higher the peak RPM, the higher the HP number.

This is why it makes so much more power. On a built 350 with a bigger: base manifold, runners, ported plenum, 52mm T/B, and a ZZ-9 cam, peak HP is 380 at 4750 RPM,and peak torque will be 460lbs/ft. Put a mini-ram on the same motor, and peak HP will be 450 at 6000 RPM, with 430lbs/ft of torque. Sure you lose some torque, but you will still have a hard time hooking up, so the torque loss is not an issue. Over a stock TPI you would see easily over 100 more HP. If we do the same combo with a 383 the modified TPI would only be at 400HP at 4500 RPM, and 515lbs/ft of torque, basically a tow truck motor, all torque, and no RPM or top end. Put a mini-ram on and you will see 480HP at 5800 RPM, with 490 lbs/ft of toque, and a lot flatter toque curve, over a TPI long runner intake. And once again you will still have trouble hooking up. This same runner concept is why the LT1 motors made 60 more HP over the TPI motors out of the box. If you look at stock TPI aluminum head flow numbers, and compare them to stock LT1 aluminum head flow numbers, you will see little difference, also the cam specs are very similar, and the throttle bodies, and cubic inches are the same. So why does the LT1 make more power? Simple, intake runner length, is the main difference, shorter runner more RPM, and RPM is HP. If GM put a 17 inch long intake runner on the LT1 motor, the numbers would be the same as the TPI motors.

* If you are running the Vortec iron heads, you will need to have them drilled and tapped for the standard SBC bolt pattern,we offer this service for $75/pair, though shipping them may not be worth it, so check some local machine shops for this service. If you have this done then you can order p/n 500-518, but you must specify you are running Vortec iron heads, and we will match the ports accordingly.
_ken :CAC
 
M

Moonunit 451

Guest
JT ZR-Won said:
Brian, welcome to the CAC:D Like Ken said, the stock TPI unit isn't to friendly above 4500 RPM. If RPM's are what you're looking for, I believe the Mini Ram is the best setup. You'll lose a couple of pounds of torque, but you'll make plenty of horsepower to make up for it. The only thing that sucks is the mini ram isn't to wallet friendly:( For a cheaper alternative, the Accel Super Ram is supposed to be pretty good also, but doesn't produce the #'s that the mini ram does............good luck & keep us posted

Jay

Hey guys lets don't forget the LT-1 conversion which is much cheaper than the MR and widely to be believed nearly the same. If you look around there is a sight that either sells the parts, gives instructions or both. Found it. http://www.lt1intake.com/ Here is a pic of the powdercoated one complete that I just sold to Mad-Mic :cool


Welcome Brian :beer
 

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