• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 1994 - 1995 Specific Tech

how hard is it to run a siamese block on the street?

  • Thread starter Thread starter milehighstang
  • Start date Start date Apr 1, 2005

milehighstang

New Member
Mar 31, 2005
54
0
0
littleton, colorado
Apr 1, 2005
#1
  • Apr 1, 2005
  • #1
hey i was really contemplating a R302 block, but because its a siamese block i have heard that it is nearly impossible to keep these blocks cool on the street. is this true? i plan on making way more power than the stock block can handle but if i cant drive it on the street than i dont want that either
 

302fordracer

New Member
Mar 27, 2004
738
0
0
Vancouver, WA
Apr 1, 2005
#2
  • Apr 1, 2005
  • #2
lol..wow you must be looking for a crapload of power...
 
C

CArkid0101

New Member
Oct 7, 2004
76
0
0
Meno Falls, WI
Apr 1, 2005
#3
  • Apr 1, 2005
  • #3
what is a siamese block? Whats the differences?
 

milehighstang

New Member
Mar 31, 2005
54
0
0
littleton, colorado
Apr 1, 2005
#4
  • Apr 1, 2005
  • #4
well they say a stock block is good to 450-500 rwhp. the R302 is rated at 1200rwhp. lets just say i plan on making a number between that. O and siamese blocks are solid castings between the cylinder bores, and there are no water passages between them. this is done for added strength. but because of that the engines can get hot!
 
T

TMC

Founding Member
Jan 17, 1999
1,426
0
36
Chicago
Apr 1, 2005
#5
  • Apr 1, 2005
  • #5
It won't be a problem on the street with the right parts to keep it cool. A decent radiator should be all you really need but a decent oil cooler would help insure it to stay cool. I've seen a few guys with R blocks on the street and they have not had any issues. One of those guys moved to AZ and hasn't overheated it even in the summer down there.
 

clang5oh

New Member
Apr 17, 2003
254
0
0
in a car that scares women and children
Apr 2, 2005
#6
  • Apr 2, 2005
  • #6
my brother in law runs a chevy 400 (all chevy 400 were siamese bore) in his 85 1500. it got a little warm but really there was never a real problem other than the pinging. it was a little built and all the factory cooling stuff kept it in line.
 

milehighstang

New Member
Mar 31, 2005
54
0
0
littleton, colorado
Apr 2, 2005
#7
  • Apr 2, 2005
  • #7
thanx guys really appreciate the info. sounds good. im not so nervous to run the r302 now. thanx
 
You must log in or register to reply here.

Similar threads

Progress Thread Progress Thread- From6to8's 95 GT/Saleen Supercharged 331 install
  • from6to8
  • Mar 22, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
24
Views
958
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- May 6, 2026
from6to8
J
1996 v6-v8 swap
  • jujuonurmom
  • Oct 28, 2025
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
0
Views
201
1996 - 2004 SN95 Mustang -General/Talk- Oct 28, 2025
jujuonurmom
J
SN95 Desktop 363 Engine Combination - Looking for input
  • WhiteCobra95
  • Sep 8, 2025
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
11
Views
1K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Oct 6, 2025
Habu135
B
water pump installation questions
  • B0udreaux
  • Feb 5, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
38
Views
2K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Feb 28, 2026
General karthief
Progress Thread BluePrint 347 long block engine swap
  • Sparky714
  • Aug 2, 2024
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 7 8 9
Replies
163
Views
10K
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- May 8, 2026
Sparky714
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 1994 - 1995 Specific Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?